Prosthetic Dentistry

The aim of the study is to evaluate the association between the number of missing teeth and demographic variables, brushing, smoking habits, and chronic systemic diseases in Baghdad city, Iraq. Materials and Methods: The cross-sectional study extended from November 2022 to March 2023. Intraoral examinations determined the number of missing teeth. Subsequently, patients completed a written questionnaire covering demographic data, habits, and systemic diseases. Data were analyzed using descriptive and inferential methods. Results: The total number of patients was 250, with 146 males and 104 females. The highest proportion (33.6%) belonged to individuals aged 31 to 45 years. Rural residents constituted 71.6%, and 59.6% were employed. Approximately half of the participants (48.8%) had a university education. The study sample revealed 40% with five or fewer missing teeth, 38% with 5 to 10 missing teeth, and 22% with 10 or more missing teeth. Among 250 patients, 28.8% reported daily tooth brushing. Additionally, 70.4% reported daily sweet consumption, 58.4% were smokers, 88.4% had diabetes, and 80% had hypertension. The increase in missing teeth was significantly associated with old age, educational level, rural residence, lack of tooth brushing, sweet intake, and complaints of hypertension and diabetes mellitus. Conclusion: Tooth loss is multifactorial, resulting from both localized defects and systemic conditions. Preserving teeth plays a vital role in improving the quality of life and oral health. There is a need to educate and enhance awareness among patients about the harmful effects of losing or sacrificing teeth.

Purpose: To evaluate the efficacy of 0.5 % Sodium hypochlorite and 2% Glutaraldehyde spray disinfectants on impression compound and irreversible hydrocolloid impressions. Material and Methods: Twenty edentulous patients (age group of 45-65 years) were randomly selected for the present study. Maxillary and mandibular impressions of 10 patients were made in compound and remaining 10 patients in alginate. All 40 impressions were swabbed and incubated on nutrient agar culture media. Both alginate and compound impressions were divided into two groups of 10 each . 50% of total impressions of alginate and compound were disinfected with 0.5% NaOCl and were designated as group –I and remaining 50% impressions of both were disinfected with 2% Glutaraldehyde and were designated as group –II respectively. Post 10 minutes, the impressions were reswabbed and incubated on nutrient agar culture media for 24-48 hours and microbial colony count was carried out. Results: Numerous gram positive and gra...

ABSTRACT Aim This study aims to compare the color parameters of two different dental shade guides from local and international manufacturers (Eray Deluxe and Vita Classical). Material and Methods A total of 320 shade samples from 10 shade guides of each brand (n = 10) were evaluated. Color measurements were performed under standard lighting conditions using a spectrophotometer. Each shade sample was measured six times, and the L*, a*, and b* values were recorded in the CIELAB color space. Color differences were calculated using the CIEDE2000 (ΔE00) formula. Statistical analyseswere conducted using the Kolmogorov-Smirnov test, independent samples t-test, and Mann-Whitney U test (α = 0.05). Results The ΔE values of the Eray Deluxe shade guide were significantly higher in all color groups compared to the Vita Classical guide (P < 0.001). The largest difference was observed in the D color group, while the smallest difference was found in the A color tones. The L* values of the Eray shade guide were higher in the D color group, while the a* values were generally lower (P < 0.05). On the b* axis, the Eray shade guide exhibited more yellowish tones. SignificantΔE00 differences were detected between the two shade guides in the most commonly selected shades (A1, A2, A3, B1, and B2). Conclusions Neither shade guide perfectly matched the target colors, but the Vita Classical guide showed lower ΔE values, indicating a closer match to the target shades. In clinical practice, differences between shade guides should be considered. Key Words Color mismatch, Dental technician, Optical properties, Pigment variation, Spectrophotometry

The aim of this study was to examine the effects of various sintering procedures on the color parameters, marginal, and internal fit of zirconia crowns. Materials and Methods: Overall, 60 zirconia crowns were produced using 3 distinct zirconia blocks (Wieland Zenostar, Zirkonzahn Ice Translucent, and Zirkonzahn Prettau). For the sintering procedure of the crowns, six groups were created as follows: Wieland-Standard, Wieland-Speed, Ice-Standard, Ice-Speed, Prettau-Slow, and Prettau-Standard programs. The crowns were assigned into groups (n = 10 in each group). The color parameters, marginal fit, and internal fit of the crowns were evaluated. The normality of data distribution was evaluated with the Kolmogrov-Smirnov test. Two independent samples t-test and Mann-Whitney U test were used to compare the sintering groups. Results: Acceleration of sintering caused a significant change in the color parameters of the Wieland and Ice groups but not in the Prettau group. In the Wieland group, marginal (p = .047) and internal (p = .004) gap values of speed sintering were found to be significantly lower than those in standard sintering. In the Ice group, the marginal gap values of speed sintering were found to be significantly lower than those in standard sintering (p = .019). In the Prettau group, the marginal gap values of standard sintering were found to be significantly higher (p = .035) than those in slow sintering. Conclusions: It was concluded that the effects of sintering procedures on color parameters, and internal and marginal fit of zirconia crowns were clinically insignificant. Speed sintering can be recommended for zirconia restorations.

This study evaluated the effect of the thickness and translucency of lithium disilicatebased glass ceramics on resin composite substrates on color change and masking effect. Laminate veneers were fabricated using IPS e.max CAD (A1) blocks with two different light transmittance values (High translucent [HT], Low translucent [LT]). Slices of two different thicknesses (0.3 mm, 0.5 mm) were obtained (n=10) and laminate veneers were cemented on the resin composite substrates of two different shades (A2, A3.5). The color change (∆E values) was evaluated with the CIELab color system using a spectrophotometer, while the masking effect was calculated. The data were analyzed using independent-samples t-test and two-way analysis of variance. The ceramic thickness and translucency had a significant effect on final color and masking. When HT was used, and the laminate veneer thickness decreased (0.3 mm), the masking effect in ΔE values were lower (p<0.05). The ∆E values (>3.7) were clinically unacceptable. With the increase in thickness, translucency of porcelain laminate veneers decreases showing better color masking ability. Veneer thickness seems to be more effective on the restoration's masking ability than the shade of the substrate and translucency. Cinically, in case a 0.5-mm or thinner laminate veneer is planned, tooth color, resin cement and ceramic type should be considered.

This retrospective study aimed to evaluate and compare the clinical performance, plaque indices, and cemented surface areas of feldspathic ceramic endocrown and overlay restorations in endodontically treated premolars and molars over a 2-to 4-year follow-up. Methods: Fifty-one restorations (24 endocrowns, 27 overlays) delivered between January 2019 and September 2022 were examined. All were fabricated in a single session using CEREC system (Omnicam AC scanner, CEREC Software v3.85, and MCXL milling unit; Sirona Dental Systems GmbH, Bensheim, Germany) from feldspathic ceramic blocks (CEREC Blok PC; Sirona Dental Systems GmbH, Bensheim, Germany) and cemented with a dualcure adhesive resin cement (G-CEM LinkForce; GC Corporation, Tokyo, Japan). Clinical performance was assessed using modified FDI criteria, including esthetic, functional, and biological parameters. Plaque index was recorded, and cemented surface area was measured using archived STL files. Statistical analyses included the Mann-Whitney U test, chi-square test, Fisher's exact test, and two-way ANOVA (p < 0.05). Results: All endocrown and overlay restorations showed a 100 % survival rate, with no failures. No significant differences were found in esthetic, functional, or biological performance (p > 0.05). Plaque index scores were similar (p = 0.253), but a strong negative correlation was observed between plaque accumulation and periodontal response (Spearman's rho =-0.846, p < 0.001). Endocrowns had a significantly larger cemented surface area than overlays (p = 0.020), but this did not impact clinical success. Conclusions: Endocrowns and overlays provided reliable, minimally invasive treatment options for endodontically treated premolars and molars, ensuring high survival rates. Although endocrowns presented a larger cemented surface area, overlays showed similar success, supporting a conservative approach. Periodontal health was not significantly affected by restoration type, but clinical success was influenced by patient hygiene (clinicaltrials.gov ID: NCT06734806). Clinical Significance: Endocrowns and overlay restorations fabricated from feldspathic and cemented with a dualpolymerized resin cement used with a bonding agent can be safely applied in a single session for endodontically treated posterior teeth.

Statement of problem. The hatch distance, which refers to the spacing between adjacent laser lines in the laser melting process, may influence the microstructure of the metal framework and, hence, the metal-ceramic bond strength. However, studies on the influence of hatch distance on metal-ceramic bond strength are lacking. Purpose. The purpose of this in vitro study was to investigate the porcelain bond strength of cobalt chromium frameworks fabricated using selective laser melting with hatch distances of 50 µm, 55 µm, and 60 µm. Material and methods. Bar-shaped cobalt chromium frameworks were fabricated using selective laser melting with hatch distances of 50 µm (Group-50), 55 µm (Group-55), and 60 µm (Group-60). After porcelain application, the metal-ceramic bond strength was evaluated using a 3-point bend test according to the International Organization for Standardization (ISO) 9693-1 standard. After the 3-point bend test, elemental analysis was performed on both the metal and porcelain interfaces of 1 randomly selected specimen from each group, and the density of 1 metal framework from each group was determined using the Archimedes method. In addition, microstructural analysis was performed on 1 metal framework from each group using optical microscopy, while 1 porcelainapplied metal framework was analyzed using scanning electron microscopy. The metal-ceramic bond strength data were statistically analyzed using a 1-way analysis of variance (α=.05) Results. Hatch distance significantly affected the metal-ceramic bond strength (P<.001). Group-50 exhibited the highest mean ±standard deviation metal-ceramic bond strength (32.99 ±3.17 MPa), which was significantly higher than Group-55 (29.98 ±2.41 MPa; P<.001) and Group-60 (29.33 ±1.83 MPa; P<.001). No significant difference was found between Group-55 and Group-60 (P=.83). The elemental analysis indicated the absence of metal alloy components Co, Cr, Mo, and W on the porcelain side of the fracture interface across all groups. The proportions of porcelain composition elements Si, Ce, Ti, Zr, K, Al, Na, and Ca detected on the metal side of the fracture interface were consistent among the groups. As the hatch distance increased, the density of the frameworks decreased while porosity within the frameworks increased. The densities of Group-50, Group-55, and Group-60 were calculated as 8.28 g/cm³, 8.14 g/cm³, and 8.06 g/cm³, respectively. Conclusions. The results revealed that hatch distance may affect the metal-ceramic bond strength and microstructure of cobalt chromium frameworks. (J Prosthet Dent xxxx;xxx:xxx-xxx)

The purpose of this study was to examine the influence of fast sintering on the optical properties, fracture strength, and microstructure of monolithic zirconia (MZ) ceramics. After 20 disc-shaped and 4 square-shaped samples from the MZ block were machined in the CAM device, groups were created by the sintering procedure in accordance with the manufacturer's recommendations: Standard (Grup S; disc-shaped n = 10 square-shaped n = 2) and fast (Grup F; disc-shaped n = 10 squareshaped n = 2). Then, hydrothermal aging was applied to all samples. To calculate translucency, opalescence, and fluorescence values, the LabCh color data of the samples were defined using spectrophotometers. The disc samples were biaxially fracture tested, and the values were determined. The chemical content, grain size (GS), and phase composition of the square-shaped samples were analyzed, respectively. Since the grain size did not conform to the normal distribution, the Mann-Whitney U test was used for statistical analysis, and all other variables were analyzed by an independent sample t test (α = 0.05). The sintering procedure affected translucency, opalescence, fracture strength, and GS significantly (P < 0.05), but not fluorescence (P > 0.05). While both groups had similar crystal structures, there were some minor differences in chemical content. All samples had a higher fracture strength than the ISO 6872 standard recommends. The sintering procedure had no clinically significant effect on the optical properties of MZ. The fast sintering procedure of MZ can be recommended.

Purpose: This in vitro study is of significant importance as it examines the effects of reusing cobalt-chromium-tungsten-containing alloy powder on metal-ceramic bond strength and microstructure, providing valuable insights into the field of dental materials. Materials and Methods: Thirty bar and nine square-shaped cobalt-chromium frameworks were produced by the conventional lost wax (Group C, [nBar=10, nSquare=3]) and selective laser melting technique (virgin powder, Group V [nBar=10, nSquare=3]; 25-times reused powder, Group R [nBar=10, nSquare=3]). X-ray diffraction, scanning electron microscopy, and ONH analysis were used to evaluate the casting ingot, powders, and frameworks' phase compositions, grain size, and microstructure. Three-point bend tests were used to assess the metal-ceramic bond strengths.

Aim: The aim of the present in vitro study was to investigate the effects of different sintering procedures on the fit, color parameters, and fracture load of monolithic fixed partial prostheses (FPPs). Materials and methods: A metal master model was scanned and FPPs were designed. Groups were created by fabricating FPPs using four different sintering procedures (n = 10): Prettau-Standard (PST); Prettau-Slow (PSL); Ice-Speed (ISP); Ice-Standard (IST). PST-PSL (Group P; N = 20) and ISP-IST (Group I; N = 20) were colored with different coloring liquids. The marginal and internal fit were measured using the silicone replica method. CIELAB values of the samples were measured using a spectrophotometer. Then, for each sample, the die was obtained from polymethyl methacrylate. The specimens were cemented into dies and tested in a universal testing machine for fracture load. One-way ANOVA was performed to assess the effect of the sintering procedure on the marginal and internal fit; fracture load; and ∆E00, ∆L', ∆C', and ∆H' values of the FPPs. Results: The PSL and PST groups showed significantly smaller internal and marginal fit values compared with the ISP group. Additionally, the internal fit values of the IST group were significantly higher than those of Group P. Sintering time reduction led to a decrease in ∆E00 values. Fracture load values were not statistically significantly affected by the different sintering procedures for both brands. Conclusion: Different sintering procedures did not have a clinically significant effect on fit and fracture load. Different sintering procedures were found to have an impact on the color change of monolithic zirconia restorations.

Metal-ceramic (MC) restorations remain a preferred prosthetic option because of their high mechanical properties, biocompatibility, acceptable esthetics, and low cost. 1 Metal frameworks of MC restorations are often fabricated by using additive manufacturing (AM) technology 2 because of shortened production time, high dimensional accuracy, the ability to fabricate complex geometrical shapes, and the maximum density of the final product. 3,4 Currently, selective laser melting (SLM) is the most commonly used AM technology for fabricating frameworks, 4,5 typically with cobalt chromium (Co-Cr) alloy powder. 6-8 An SLM machine consists of 2 main parts: the laser source and the fabrication room. The room includes a powder supply chamber, building chamber, coater, and overflow container (Fig. 1A). In the SLM process, Co-Cr alloy powder in the supply chamber is lifted, and the build plate is moved down according to the selected layer thickness. The lifted alloy powder is then swept into the SLM machine's build plate and overflow container through the coater (Fig. 1B). A laser beam melts the spread powder layer according to the scanning track. This cycle is repeated for each layer until the metal framework is built. When the production is finished, the metal framework on the build plate remains embedded in unmelted alloy powder 9 which has been exposed to high temperatures during the melting of each layer. 10 After sieving, the unmelted metal powder remaining in the build chamber of the SLM device can be used by

Despite growing interest in zirconia-reinforced resin composites, the influence of manufacturing techniques on their surface and optical stability remains unclear. Purpose. The purpose of this in vitro study was to evaluate the surface characteristics and color stability of zirconia-reinforced resin composite materials produced via 3 techniques: 3-dimensional (3D) printing, subtractive manufacturing, and layering. Material and methods. Thirty-six disks (Ø10×1.0 mm) were prepared and divided into 3 groups: 3D printing (PriZma 3D Bio Crown; MakertechLabs), subtractive manufacturing (Lava Ultimate; 3M), and layering (Filtek Z350 XT; 3M). Surface properties were assessed using roughness analysis and scanning electron microscopy (SEM). Color coordinates (L*, a*, b*) were recorded using a spectrophotometer (SP60; X-Rite) at baseline, after staining (coffee or red wine for 12 days), and after repolishing (Superfix Dental Finishing & Polishing Disc System; TDV). Statistical analysis included color differences (∆E 00 ) and translucency parameter differences (∆TP 00 ), considering acceptability (AT) and perceptibility thresholds (PT) (α=.05). Results. Three-dimensional printing exhibited higher Ra than subtractive (P<.001) or layering (P=.010). For Rz, 3D printing and Layering were similar and better than Subtractive (P<.001). SEM revealed porous surfaces in 3D printing, contrasting with denser surfaces in Subtractive and Layering. All groups showed color changes exceeding AT, with 3D printing significantly higher after coffee or red wine exposure (P<.05). Repolishing reduced the ∆E 00 of Subtractive below PT after coffee staining and below AT after wine staining. ∆TP 00 altered after coffee staining, with Subtractive below AT after wine staining. Repolishing reversed ∆TP 00 below AT for all conditions. Conclusions. Three-dimensional printing and layering resulted in higher surface roughness, greater color changes, and lower translucency than the subtractive technique. (J Prosthet Dent xxxx;xxx:xxx-xxx)

Several aspects of the biology of Cycloramphus species of the Atlantic Forest are still poorly known, which makes it difficult to understand their historical relationships. Therefore, we were stimulated to promote a comparative cytogenetic analysis of several species of the genus Cycloramphus. The study of Cycloramphus acangatan, C. boraceiensis, C. brasiliensis, C. carvalhoi, C. eleutherodactylus, C. fuliginosus, C. lutzorum, and C. rhyakonastes, revealed that these eight species share a diploid number 2n = 26. Cycloramphus fuliginosus presented the most distinct karyotype, due to the presence of subtelocentric chromosomes in pairs 1 and 4. The main diagnostic feature observed in the other species was the presence of one pair of telocentric chromosomes in C. boraceiensis, C. carvalhoi, and C. eleutherodactylus, while the remaining species presented karyotypes composed exclusively of biarmed chromosomes. Constitutive heterochromatin was predominantly located in pericentromeric regions in all species,

A new species of the rarely reported genus Euryozius Miers, 1886, is described from the Philippines and is distinguished from its congeners by carapace and ambulatory leg proportions, anterolateral margin armature, and form of the frontal margin. This new species, Euryozius camachoi, ...

Objective: To measure the treatment outcomes of the restorative procedures for children undergoing dental rehabilitation performed by dental
intern and residents (MSc, PhD and Saudi Board) at King Abdulaziz University Faculty of Dentistry (KAUFD), Jeddah, Saudi Arabia.
Materials and methods: Sixty-one dental digital records of healthy patients undergoing comprehensive dental treatment were viewed by a
single examiner. These patients were treated by dental interns, and residents (MSc, PhD and Saudi Board) at KAUFD, Jeddah, Saudi Arabia
between 2015 and 2016. Only records of patients who returned for follow-up at least 6 months after their rehabilitations were evaluated.
Results: Compared to stainless steel crowns (SSCs) failure rates, preventive resin restorations (PRRs) failure rates were higher, but not
statistically significant (P=0.559). Compared to the failure rates of SSC restorations, failure rates in composite restorations were significantly
higher (p<0.0001).
Conclusions: SSCs are the most reliable restorations for carious teeth after six months recalls.

Purpose: The purpose of this study was to evaluate, in vitro, the efficacy of 10 percent carbamide peroxide used as an intracoronal bleaching agent in bloodstained primary teeth. Methods: Thirty extracted primary canines were stained using rabbit blood and randomly divided into two groups of 15 teeth each. Stained teeth in the test group were bleached intracoronally using 10 percent carbamide peroxide for 21 days. The bleaching agent was replaced at days seven and 14. The control group was not subjected to bleaching, and a cotton pellet damped with distilled water was placed in the pulp chamber. Shade alteration from the prestaining value was evaluated using a VITA Easyshade spectrophotometer at days zero, seven, 14, and 21. Results: All specimens in the test group returned to the initial baseline shade, with no significant differences from the prestaining values (P=0.097). Teeth in the control group did not undergo any shade alteration after staining, with no significant differences noted from the prestaining values (P<0.001). Conclusions: Intracoronal bleaching using 10 percent carbamide peroxide is an effective approach for whitening discolored extracted primary teeth.

Dermatophagy, the act of consuming shed skin, is documented across various amphibians and reptiles but remains understudied. This study presents the first recorded observation of dermatophagy in Himalayan toad (Duttaphrynus himalayanus) from Pokhara, Nepal. The toad was observed consuming its entire shed skin during a rainstorm, a behavior captured on video over 6 minutes and 18 seconds. We recorded complete consumption of the old skin, unlike previously reported partial dermatophagy in this genus. This observation expands the knowledge of dermatophagy in amphibians.

Prosthetic designs to reduce the risk of peri-implantitis should apply prosthetic principles developed for tooth supported prosthetics. Peri-implantitis and periodontitis are similar bacteriologically, pathologically, and histologically. These designs facilitate effective patient oral hygiene maintenance reducing bacterial plaque accumulation at the interface, the Free Margin of the Gingiva.  Currently there are limited design recommendations and illustrations for dentists and dental technologists to design and produce implant supported prosthetics applying these principles within the limitations of the current production processes.  Evaluation of patient's ability to comply with oral hygiene maintenance should be considered when choosing the best design for each situation.

This clinical report describes a straightforward alternative treatment for adult patients with extruded maxillary molars, who are reluctant to use fixed appliances and complex mechanics. The maxillary molar supereruption of a 57-year-old woman was treated using buttons bonded to the buccal and palatal surfaces of the molars, 2 mini-implants, and elastomeric chains. The intrusion was achieved in 5 months. The treatment stability was observed for 5 years after treatment. (J Prosthet Dent 2017;118:1-4)

This clinical report describes a straightforward alternative treatment for adult patients with extruded maxillary molars, who are reluctant to use fixed appliances and complex mechanics. The maxillary molar supereruption of a 57-year-old woman was treated using buttons bonded to the buccal and palatal surfaces of the molars, 2 mini-implants, and elastomeric chains. The intrusion was achieved in 5 months. The treatment stability was observed for 5 years after treatment. (J Prosthet Dent 2017;118:1-4)

The dimensional accuracy of four duplicating materials, including one brand of agar reversible hydrocolioid, one brand of polyether rubber, and two brands of polyvinyl siloxane tdddition siliconei rubber was studied. A standard stainless steel specimen of 76 x 76 x 9.5 mm was made. Vertical and horizontal grooves were made on the specimen as reference marks. The horizontal grooves were in different depths and widths. The duplicating materials were prepared and poured over the standard die to make a negative likeness. These negatives were poured with the same investment material. Twelve investment specimens were measured for accuracy and detail reproduction with a Talysurf finish analyzer. Results of this study indicated that polyvinyl siloxane and polyelher rubbers are superior in accuracy compared to the agar reversible hydrocolloid. No significant differences in detail reproduction were noted in anv of the duplicating materials tested.

O protocolo sobre implantes, também conhecido como prótese tipo protocolo ou All-on-4/All-on-6, representa uma das mais importantes modalidades de reabilitação oral fixa em pacientes edêntulos totais ou com dentição comprometida. Este trabalho tem como objetivo revisar os aspectos históricos, biomecânicos, clínicos e sociais relacionados a essa técnica, abordando indicações, limitações e perspectivas futuras. A literatura aponta taxas elevadas de sucesso, quando associada a planejamento digital e execução criteriosa. No contexto brasileiro, o protocolo sobre implantes é cada vez mais valorizado, por devolver função, estética e qualidade de vida aos pacientes.

Restoration of maxillary defects resulting from tumor ablative surgery presents a difficult challenge, with both functional and esthetic issues. Whether rehabilitation with an obturator prosthesis could significantly contribute to improved quality of life in patients with maxillary resection has been scarcely studied, with relatively small study samples. The purpose of this survey study was to assess the overall functioning of the obturator prosthesis and the effect of specific sociodemographic, medical, and treatment variables on obturator functioning and quality of life in patients with maxillectomy. Global quality of life (QOL) and satisfaction with the obturator prosthesis of 57 patients who underwent maxillectomy and prosthetic rehabilitation at the National and Kapodistrian University of Athens were assessed using 3 questionnaires: European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire C30 (QLQ-C30), the EORTC QLQ-HN35, and the obturat...

Background: This study aimed to evaluate the attitudes of trainee dentists who have completed pediatric dentistry internships and performed preventive, restorative, and pulpal treatments in pediatric patients to pediatric dentistry. Methods: An 18-question questionnaire was designed for participants to complete. The questionnaire form, uploaded online via Google Forms, was distributed digitally via a link. The study data were reported using descriptive statistics (numbers and percentages). Analyses were performed in the IBM SPSS 25 program. Results: It was observed that 85% of the trainee dentists participating in the study expressed concerns about caring for pediatric patients prior to receiving a pediatric dentistry internship. It was observed that in response to the question, "What is the treatment that you find the most difficult to treat in pediatric patients?" 85.5% of the trainee dentists responded that pulpotomy of primary teeth was the most challenging. Conclusion: It was observed that most of the dental students who participated in the study were concerned about the care of pediatric patients and experienced stress while treating pediatric patients. It was found that this situation negatively affected their desire to specialize in this field. Increasing dental students' knowledge and experience in treating pediatric patients during their training and equipping them with behavioral techniques to establish good relationships with children will help them treat more pediatric patients.

Background and objectives: This in vitro study was undertaken to evaluate the effect of air abrasion and acid etch surface pretreatment of denture base resin on tensile bond strength of two long term resilient liners. Method: A total of 120 heat cure PMMA resin blocks were prepared for producing 60 PMMA specimens with soft liner in between two blocks. The study comprised of 60 specimens divided into 3 groups. Each group containing 20 specimens. GROUP Iair abrasion with 50-μm Al2O3 particles (Abrasion group). GROUP II36% phosphoric acid etching (acid group). GROUP IIIControl Group. Each group was divided into two subgroups. Subgroup A was relined by Molloplast B and Subgroup B was relined by Ufi Gel P. Tensile bond strength was tested using universal testing machine. Results and conclusions: Among the soft liners tested for tensile bond strength, it was found that tensile bond strength was highest for acid etching and lowest for air abrasion group. Mean bond strength of Molloplast B ...

The installation of dental implants requires precise planning that considers vital anatomic structures and the long-term success objectives of implant survival. 1 Implants should be placed in the best position for functional and esthetic restoration. In computer-guided implant surgery (CGIS), the combination of computed tomography (CT) imaging with computer-aided design and computer-aided manufacturing (CAD-CAM) technology

There are several factors to consider while a tooth is to be replaced with an implant in the anterior region and achieving an esthetic result is even more challenging. We must evaluate numerous criteria to achieve the optimal esthetics. This article details a technique to replicate the soft tissue support and thus replicate the gingival margin position developed with the provisional restoration to achieve high functional and esthetic results.

Conventional complete denture prosthetics require several appointments to register the maxillomandibular relationship and evaluate the esthetics. The fabrication of milled complete dental prostheses with digital scanning technology may decrease the number of appointments. The step-by-step method necessary to obtain impressions, maxillomandibular relation records, and anterior tooth position with an anatomic measuring device is described. The technique allows the generation of a virtual denture, which is milled to exact specifications without the use of conventional stone casts, flasking, or processing techniques.

Statement of problem. Denture base resins (DBRs), such as polymethyl methacrylate (PMMA), are commonly used in the fabrication of removable dentures because of their physical, mechanical, and esthetic properties. However, the denture base acts as a substrate for microorganism adherence and biofilm formation, which may lead to denture stomatitis and be further complicated by fungal infections, of especial importance with geriatric and immunosuppressed patients. Therefore, methods to enhance the antimicrobial property of DBRs will be beneficial. Purpose. The purpose of this systematic review was to evaluate the literature on the antimicrobial activity of DBRs incorporating antimicrobial agents or materials. A search of English peer-reviewed literature up to February 2019 reporting on antimicrobial activity of DBRs with respect to antimicrobial agents or materials, antimicrobial test effects and methods, and conclusion or knowledge gaps was conducted by using Embase, Google Scholar, PubMed, and Web of Science databases. Search terms included denture base resin and antibacterial, denture base resin and antifungal, and denture base resin and antimicrobial. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied for subsequent data analysis. Results. Of 2536 identified articles, 28 met the inclusion criteria for the systematic review. Antimicrobial materials were divided into 3 groups: antimicrobial monomer or copolymer, 2 phytochemical or phytomedical components, and other compounds. Strategies on how to incorporate these substances into DBRs and their impact on the reduction and prevention of the growth of microorganisms were identified. Conclusions. Although many efforts have been made to improve the antimicrobial ability of DBRs, this systematic review found that the effectiveness of incorporating of antimicrobial agents into DBRs has not been demonstrated conclusively. Potential antimicrobial activity of denture base resins (DBRs) is an important issue for geriatric and immunocompromised patients, and further research is needed to identify techniques of incorporating biodegradable microcapsules or nanocarriers containing organic antimicrobial agents into denture base materials.

Statement of problem. Long-term clinical data are lacking on the comparison of the survival of adhesively luted pressed e.max lithium disilicate glass ceramic complete and partial coverage restorations in posterior dentitions and the effect that different technical and clinical variables have on their survival. Purpose. The purpose of this clinical study was to examine and compare the 16.9-year survival of posterior pressed e.max lithium disilicate glass ceramic complete and partial coverage restorations and associated clinical parameters on the outcome. Patients requiring either single-unit posterior defect-specific partial coverage or complete coverage restorations were recruited in a clinical private practice. The participants were offered the options of direct restorations, partial coverage cast gold, or glass ceramic (lithium disilicate) restorations. Those requiring complete coverage restorations were given the options of complete cast gold, metal-ceramic, or glass ceramic restorations. Only participants who chose glass ceramic partial and complete coverage restorations were included in the study. The overall survival of the glass ceramic restorations was assessed by the clinical factors determined at recall. The effect of various clinical parameters (type of restoration, dental arch, tooth position in the dental arch, age and sex of participant, and ceramic thickness) was evaluated by using Kaplan-Meier survival curves to account for attrition bias and other reasons for failure. The statistical significance of differences between parameters was determined using the log rank test (a=.05). Results. A total of 738 participants requiring 2392 lithium disilicate restorations in posterior teeth were evaluated. The mean age of the participants at the time of restoration placement was 62 (range: 20-99 years, 302 men and 436 women). Of 2392 units, 1782 were complete and 610 were partial coverage restorations. A total of 22 failures (bulk fracture or large chip) requiring replacement were recorded with the average time to failure 3.5 (0.02-7.9) years. The total time at risk computed for these units was 13227.9 years, providing an estimated failure risk of 0.17% per year. The 16.9-year estimated cumulative survival was 96.49%. The estimated cumulative survival of posterior complete (n=1782) and posterior partial coverage restorations (n=610) was 96.75% at 10.5 years and 95.27% at 16.9 years (P<.05). Of the 22, 16 failures were recorded for the complete coverage restorations. The total time at risk for these restorations was 10144.5 years, providing an estimated risk of 0.16 per year. The other 6 failures recorded occurred for the partial coverage restorations. The total time at risk for these restorations was 3083.5 years, providing an estimated risk of 0.19% per year. No statistically significant difference was found in the survival of posterior complete and partial coverage restorations among men and women, different age groups, or posterior tooth position in the dental arch (P>.05). The thickness of the restoration also had no influence on the survival of glass ceramic posterior restorations (P>.05). Conclusions. Pressed e.max lithium disilicate complete and partial coverage restorations showed high survival rates in posterior teeth over a 16.9-year period, with an overall failure rate of 0.17% per year. Risk of failure at any age was low for both men and women. No statistically significant difference was found in the survival of complete and partial coverage restorations, and none of the confounding variables, including the thickness of the restoration, appeared to have a significant effect on survival.

Background: Dental condensable composite resins were used as a substitute for dental amalgam to restore posterior teeth. They were be condensed as dental amalgam, which made it easier to produce an accurate proximal teeth contact. Objectives: The aim of this study was to measure the top and bottom hardness of two condensable composites at different thicknesses (2,3,4 and 5 mm) at different loads (25,50 and 100 gf). Percent depth of cure was calculated for both materials at the different thicknesses. The correlation between the hardness and percent depth of cure was calculated. Materials and methods: The materials used were Glacier and SureFil condensable composite resins. 120 specimens were prepared from both composite resins, 60 specimens each using transparent Perspex molds of 4mm diameter and thicknesses of 2,3,4,5 mm. Specimens of each composite resin were divided into 4 groups corresponding to the different thicknesses, 15 specimens for each thickness. Specimens for each thickness were further divided into 3 subgroups, 5 specimens for each load applied during hardness testing (25, 50 and 100gf). The hardness was measured using a universal micro hardness testing machine for the top and bottom surfaces of each specimen. Percent depth of cure was calculated by dividing the bottom hardness value by the top hardness value and multiplied by 100. Also, the correlation between the hardness and percent depth of cure was calculated. Results: The results indicated that, the top hardness values were greater than that of the bottom hardness values for both composite resins. Glacier composite showed that, the hardness was increased by increasing the testing loads and decreased by increasing the thickness, except at 3 mm thickness of Glacier, which showed higher hardness than 2 mm thickness. Also, SureFil composite resin showed increased hardness values by increasing the testing loads and decreased by increasing the thickness. The hardness of 3mm thickness was greater than that of 2mm thickness. The percent depth of cure in 2mm and 3mm thicknesses were more than 80%, while the other thicknesses showed percent depth of cure less than 80%. Both materials showed high positive correlation between the hardness and percent depth of cure. Conclusions: The top hardness was greater than that of the bottom hardness. The hardness of 3mm thickness was greater than that of 2mm thickness. The hardness was increased by increasing the testing loads and decreased by increasing the thickness. The percent depth of cure was decreased by increasing thickness. There was high positive correlation between the hardness and percent depth of cure.

Infection control is essential for the success of prosthodontic and oral implant procedures, as microbial contamination can lead to serious complications such as denture stomatitis and peri-implantitis. While synthetic disinfectants like chlorhexidine are commonly used, they may cause side effects including irritation, toxicity, and the development of microbial resistance over time. Natural products derived from plants, animals, and minerals are currently being explored as safer alternatives. Compounds such as epigallocatechin gallate from green tea; eugenol from clove oil; quercetin, thymol, cinnamaldehyde, and flavonoids from propolis; and terpinen-4-ol from tea tree oil have shown strong antimicrobial and anti-biofilm properties. These natural agents are not only effective against harmful oral bacteria but also promote healing, are more biocompatible, environmentally friendly, and are often preferred by patients. However, challenges remain regarding their routine clinical use. The strength and composition of natural agents can vary, and there is a lack of consistent product standards, clinical trials, and comprehensive safety data. Currently, these products are not approved by the U.S. Food and Drug Administration for dental use and are only available as over-the-counter remedies. Production costs and scalability must also be evaluated in comparison with synthetic alternatives. Emerging technologies, such as nanocarriers and targeted delivery systems, are being developed to enhance the effectiveness of natural agents in dental applications. Further clinical research and the establishment of clear regulatory guidelines are necessary to support their integration into clinical practice. Natural disinfectants hold significant potential to become valuable, safe, and sustainable tools for maintaining hygiene in prosthodontics and oral implantology.

The distal offset placement of a single implant to replace a single tooth would overcome the shortcomings of the placement of a single wide implant in the posterior region. However, long-term evaluation is still-lacking. The purpose of this study was to evaluate the long-term outcomes of patients treated with a single tooth restoration supported by a distal-offset placed implant. Thirty-one patients with a single restoration supported by an off-center placed implant were evaluated. The patients&#39; demographic data were described. The known implant length was used as a reference to calibrate the linear measurements on digital periapical radiographs. Implant details, survival, and prosthetic complications were analyzed. The implant survival rate was analyzed with the Kaplan-Meier method. Thirty-four implants were placed with a distal offset to support single-tooth restorations. Twenty patients were women, and patient age was 56 ±12 years. The implants had a follow-up time from loadi...

Objective Mandibular fracture is the most common maxillofacial fracture accompanied by complaints of malocclusion and pain. This causes a decrease in the quality of life. Mandibular fracture management can be done with open reduction and internal fixation or intermaxillary fixation. The Oral Health Impact Profile (OHIP 14) and the General Oral Health Assessment Index (GOHAI) were used to evaluate the quality of life after surgical treatment based on the distribution of age, sex, type of neglect, and surgical management. Materials and Methods This research is an analytic study with an analytical observational method with total sampling. The total sample used was 15 patients during the 2006 to 2020 period. The results of this study were scored, and then, the data were processed using the eta test. Results The results of the study based on the OHIP 14 parameters showed the results of each distribution, namely, age: p = 0.154, gender: p = 0.080, neglected type: p = 0.080, and management...

Those with an Angle Class III malocclusion have a reduced masticatory efficiency. The distinctive chin was a characteristic of the Habsburg (Hapsburg) dynasty. But was this the cause of the 'eating and digestive disorders' of Carlos II, the last ruling member of the Spanish Habsburg family? A lack of posterior occluding units 'leads to the premature swallowing of incompletely-chewed particles, to longer chewing, or to the avoidance of foods difficult to chew'. When orthodontic malocclusion is considered, 'only an Angle Class III exhibits a clearly reduced masticatory efficiency'. When looking at associations between such malocclusions and gastrointestinal disturbances, a recent study has showed that 'patients (with a severe Class III malocclusion) reported significantly more severe reflux symptoms than the 20 control subjects'. But taken as a whole, this article gives scant evidence for the much vaunted statement 'the first digestion takes place in the mouth'.

Objectives: There is scant information regarding the multifactorial aetiology of denture stomatitis (DS) in the world and, despite its frequency, associated factors are not completely understood. The aim of this study was to investigate the risk factors that may be associated with this lesion. Methods: A total of 70 edentulous patients, all wearing removable dentures, were divided into two groups. The test group comprised 43 patients with DS and the control group comprised 27 subjects with clinically healthy palatal mucosa. A thorough history-taking and physical examination were carried out; the subjects also answered a questionnaire. The serum level of vitamin A for each subject was assayed from a blood sample taken after the examination. Results: This study showed a significant relationship between the incidence of DS and three major factors: denture age (in terms of years), the practitioner manufacturing the dentures (general dental practitioner versus dental hygienist), and the nightlong wearing of dentures. Also, the vitamin A serum level was low in 94.29% of all subjects (cases and controls). Conclusion: Although many predisposing conditions were related to this situation, the most important risk factor was the continuous use of the dentures.

In dental practice, the fidelity of a model is given by the quality and type of material used, the technique by which it is made, and last but not least by the experience and skill of the dental technician. But, the emergence of CAD-CAM technology has led to a major change in the stages of making the working model, through the development of the virtual model. Thus, the purpose of this material is to perform a comparative study between several techniques for obtaining sectional working models, with or without pins, compared to the virtual model obtained by CAD-CAM technique.

Prosthetic rehabilitation of the maxillary front teeth is an extremely laborious problem for the dental team, consisting of the dentist and the dental technician. If for the physiognomic component the most recommended materials are the ceramic masses, for the resistance substrate there are several variants. Conventional technologies using dental alloys and modern ones involving the use of zirconium dioxide can be used successfully in performing fixed prosthetic restorations in the maxillary frontal area, both options having both advantages and disadvantages, as we will describe in this material.

A escolha errada do sistema cimentante pode levar ao fracasso clínico na cimentação de coroas e próteses parciais fixas. Este trabalho teve como objetivo estudar "in vitro" a espessura de película de seis cimentos odontológicos para fixação de peças protéticas, de três grupos distintos, sendo eles: dois cimentos de fosfato de zinco, dois cimentos de ionômero de vidro convencional e dois cimentos resinosos. Foi realizado a manipulação dos cimentos de acordo com as instruções dos fabricantes e após, interposto 1g de material entre duas placas de vidro polidas e sobre as mesmas um peso de 3 Kg, durante 10 minutos. Estas placas foram medidas com um paquímetro digital antes e após a presa dos materiais. Foi realizada a análise estatística com o teste T Student e com o Teste de Variância ANOVA e foi observado uma menor espessura de película de um cimento de ionômero de vidro perante os outros cimentos testados, com diferenças estatísticas ao nível de 5%. Os autores concluíram que o cimento de ionômero de vidro obteve a menor espessura de película, sendo apropriado para cimentação de coroas e pontes fixas.

In spite of numerous previous studies, there is no final conclusion on which type of cement is the best for dowel cementation. The purpose of this study was to compare the retention of dowels cemented with three different cement types: zinc phosphate, glass-ionomer, and compomere. Thirty teeth were divided into 3 groups, root-canals were prepared to ISO 140, to 7 mm depth and dowels were cemented. After 40 hours the tensile force needed to dislodge the dowels was recorded. For zinc phosphate it was 175±33.17 N, for glass-ionomer 235.5±46.93 N, and for compomere 275.63±96.42 N. The dowels cemented with compomere had significantly higher tensile strength than those cemented with zinc phosphate or glass-ionomer cement. Glass-ionomer cement had significantly higher tensile strength than zinc phosphate cement. The advantages of zinc-phosphate are its low price and simple usage. Thus, in many clinical situations it may be the cement of choice.

Purpose: The aim of this study was to clarify the effect of addition of glass fibers and titanium dioxide nanoparticles to the conventional acrylic resin. The tested parameters were monomer release, deflection at fracture, flexural strength, flexural modulus, and toughness. The modified acrylic resin groups were compared to the conventional unmodified and high impact types. The correlation between the tested material properties was also evaluated. Materials and methods: The materials used were conventional unmodified and high impact acrylic resins. The conventional acrylic resin was modified using 5% glass fibers and 5% titanium dioxide nanoparticles. Specimens were prepared according to the manufacturer's instructions and American Dental Association Specification No. 12. Monomer release was measured using isocratic high-performance liquid chromatography. Deflection at fracture, flexural strength, and flexural modulus were measured using three point-bending test with a universal testing machine. The toughness was related to the total area under the load-deflection curve up to the breaking point. The correlation between the tested properties was clarified. Results: All materials released monomer with varying values. The tested materials exhibited comparable values of deflection at fracture. Specimens modified with glass-fibers showed improved flexural strength and toughness similar to that of the high impact acrylic resin. Specimens modified with titanium dioxide nanoparticles exhibited reduction in the flexural properties and toughness. No significant changes were observed in the flexural modulus. There were positive correlations between the flexural strength, flexural modulus and toughness. On the contrary, there was negative correlation between deflection at fracture and flexural modulus. Conclusions: The most commercially successful method for reinforcement to date is the rubber toughening. The conventional acrylic resin denture base material could be reinforced by glass fibers while titanium dioxide nanoparticles could not. The tested materials released comparable amounts of monomer.

This study compared the retention of proBase hot versus a conventional heat-cured acrylic resin denture bases. Two completely edentulous patients of U-shaped and V-shaped palatine vault. Primary and secondary impressions of the maxillary arch were done to produce two master casts. Each master cast was duplicated into twenty-one stone casts using duplicating hydrocolloid. Standardized maxillary waxed denture bases were produced by duplication using silicone impression material. Twenty-one standardized denture bases for each tested (U-and V-shaped) maxillary arches were obtained. Stainless steel wire loops were placed at a vertical direction in the marked center of each waxed denture base for dislodging each acrylic denture base from its basal seat to measure its retention. Fourteen waxed denture bases constructed for each of U-and V-shaped palatal vault were processed into conventional heat cured acrylic, while the other seven waxed denture bases were processed into ProBase Hot denture bases as recommended by the manufacturer. A digital force meter was used for retention measurement. The results indicated a significant differences between the tested materials and the two arch forms. ProBase Hot showed the highest retention than that of the conventional acrylic resin (Acrostone) either long-curing or short-curing method.

Materials and Methods: Two types of dentures base materials were used (Vertex Thermosense and Major.base.20). Twenty wax specimens were prepared from both materials of 65 mm long, 10 mm wide, and 3 mm thick. The wax specimens were flasked and processed according to the ANSI/ADA specification No. 12 for denture base polymer and according to the manufacturer's instructions. The dimensional changes were measured immediately after deflasking, one day, two days and three days of water storage. The dimensional changes were measured using micrometer. For water sorption, twenty disk specimens of 50 ± 1 mm in diameter and 0.5 ± 0.05 mm thick were prepared. Water sorption was measured using an electronic balance. The results of this study showed that, Vertex Thermosense denture base material exhibited higher dimensional changes and water sorption than that of the conventional material (Major.base.20). ThermoSense showed significant shrinkage all over the tested periods. On the other hand, Major.base.20 denture base material showed significant expansion to compensate the curing shrinkage after 3 days of water storage. Vertex ThermoSense showed significantly higher water sorption than that of Major.base.20. Both materials exhibited increasing amount of water sorption up to 3 days. Vertex™ ThermoSense is the innovative, virtually unbreakable, new monomer-free rigid denture base material from Vertex-Dental B.V. The company offers many advantages for its product such

This study was conducted to investigate the maxillary denture bases and occlusal discrepancies using the Vertex Thermosens in comparison with the conventional polymethyl-methacrylate materials. Twenty maxillary denture bases were prepared from the Vertex ThermoSens and a conventional heat-cured denture base materials. Acrylic maxillary second molars were arranged in their respective positions on the ridge. After curing of both types of denture bases, they were deflasked with their respective master casts. Reference points were prepared for measurements of the antero-posterior and cross-arch dimensions at the denture borders using caliper device. Furthermore, the teeth discrepancies were measured between reference points in the ligual aspect of the second maxillary molars. The recorded data was analyzed using SPSS statistical software version 20. The results showed initial shrinkage of both denture bases in the antero-posterior and cross-arch dimensions immediately after decasting. This contraction was compensated gradually during storage in water up to 2 weeks. Regarding the variable time, there was a significant difference between the tested materials. Moreover, the results revealed occlusal discrepancies and shifting of teeth inward immediately after decasting, followed by outward movement after storage in water for 2 weeks. Regarding the variables time and materials, there were significant differences. Both materials exhibited inward shrinkage in the antero-posterior and cross-arch dimensions immediately after decasting. Both denture bases showed inward shifting of teeth immediately after decasting, followed by outward movement after storage in water up to 2 weeks.

Background: Degree of monomer conversion during processing of acrylic resin denture base materials is very critical in determination of monomer release and mechanical properties of acrylic resin in service. Objectives: The purpose of this research project was to investigate the effect of aluminum oxide powder reinforcement on the degree of monomer conversion, residual monomer, deflection at fracture and flexural strength after processing of heat-cured acrylic resin denture base materials. Also, the correlation between these properties was statistically tested. Materials and methods: The materials used were conventional heat-cured and aluminum oxide powder-reinforced acrylic resin denture base materials (2.5 % and 5% aluminum powder). Samples were prepared according to the manufacturer's instructions, ADA Specifications no. 12 and the International Organization for Standardization Recommendation. Acrylic resin samples of specific dimensions were prepared from unreinforced and reinforced acrylic resin materials using stainless steel plates. The degree of conversion was determined using FTIR Spectrometer. The concentrations of released methyl methacrylate monomer was measured using isocratic high-performance liquid chromatography. Flexural strength was tested using three point-bending test with a universal testing machine. Results: Aluminum oxide powder reinforcement showed slight increased degree of conversion than that of the unreinforced denture base resins. The released monomer in deionized water from the reinforced acrylic resins was significantly lower than that of the unreinforced specimens. The deflection at fracture of the reinforced specimens was significantly lower than that of the unreinforced acrylic resin. The flexural strength was significantly increased by addition of 2.5 % and 5 % aluminum oxide powder when compared to the unreinforced group. There was high positive correlation between the degree of conversion and flexural strength. On the other hand, there was negative correlation between degree of conversion and monomer release. Conclusions: Aluminum oxide powder reinforcement was slightly increased the degree of conversion of the heat-cured acrylic resin. Aluminum oxide powder reinforcement was significantly reduced the amount of monomer released and the deflection at fracture heat-cured specimens. The reinforced specimens showed significantly increased flexural strength than that of the unreinforced specimens. There was high positive correlation between the degree of conversion and flexural strength. There was negative correlation between degree of conversion and monomer release.

Objectives: Effect and correlation of aluminum oxide powder on degree of conversion, residual monomer and flexural properties of heat-cured acrylic resin specimens were studied. Materials and methods: Heat-cured acrylic resin and aluminum oxide powders were used. Specimens of specific dimensions from unreinforced and reinforced acrylic resins using stainless steel plates were prepared. Degree of conversion was determined using FTIR Spectrometer. Released monomer was measured using isocratic high-performance liquid chromatography. Flexural strength was tested using three point-bending test. Results: Aluminum oxide reinforcement showed increased degree of conversion than that of the unreinforced specimens. Released monomer from reinforced specimens was lower than that of unreinforced specimens. Deflection at fracture of reinforced specimens was lower than that of unreinforced specimens. Flexural strength was increased by addition of 2.5 % and 5% aluminum oxide. There was a positive correlation between degree of conversion and flexural strength. There was a negative correlation between degree of conversion and monomer release. Conclusions: Aluminum oxide powder increased degree of conversion and flexural strength but reduced monomer release and deflection at fracture. There was a positive correlation between degree of conversion and flexural strength. There was a negative correlation between degree of conversion and monomer release.