Purpose: The purpose of this study was to evaluate the effect of denture base material on the peri-implant stresses of overdentures held in place by inclined and straight implants during axial dislodgments. Materials and methods: Four heat-polymerized polymethylmethacrylate (PMMA) resin edentulous mandibular overdenture models were divided with respect to their denture base material and angulation of the implants in bilateral canine region in all four groups: group I (model with two parallel implant-supported PMMA overdentures), group II (model with two parallel implant-supported thermoplastic nylon overdentures), group III (master model with two inclined implant-supported PMMA overdentures) and group IV (master model with two inclined implant-supported nylon overdentures). All overdentures were secured with a ball and socket attachment and connected with strain gauges placed around implants. The stresses were measured under a 100N compressive load using an eight-channel strainometer linked to a universal testing machine. Student t-test was done for comparison between two study groups, and a one-way analysis of variance (ANOVA) was used for comparison of stresses at different implant sites in each group. Results: Straight implants experience higher levels of stresses in PMMA overdenture (group I) than nylon overdenture (group II) at all sides, and the difference was statistically significant. Inclined implants experience higher levels of stresses in PMMA overdenture (group III) than nylon overdenture (group IV) at all sides, and the difference was statistically significant at all sides except mesial side (p = 0.145). Inclined implants (group III) experience higher levels of stresses than straight implants (group I) at all sides with both PMMA and nylon overdentures. Conclusion: Peri-implant stresses were more with PMMA overdentures compared to nylon overdentures on both straight and inclined implants. Nylon overdentures with straight or inclined implants can be given as it generates less stresses compared to PMMA overdentures.

Purpose: Comparative assessment of the adhesive bond strength of conventional glass ionomer cement (GIC), 25% propolis-modified GIC and 50% propolis-modified GIC to human dentin. Materials and methods: Forty-five human permanent molars were embedded in acrylic resin block. GIC was modified with 25% ethanol-soluble liquid propolis (ESLP) solution and 50% ESLP to prepare 25% propolis-modified GIC and 50% propolis-modified GIC, respectively. The enamel was removed to expose the dentin followed by conditioning of the dentin surfaces. The samples were randomly divided into three groups: conventional GIC (group A), 25% propolis-modified GIC (group B), and 50% propolis-modified GIC (group C). Standardized-size molds were applied to the exposed dentin, and the GIC was bonded within these molds to form GIC cylinders. Shear bond strength was evaluated after incubation and thermocycling to simulate the oral environment using a universal testing machine. The statistical analysis was performed using one-way analysis of variance (ANOVA) and post hoc Tukey's test. Results: There was significant difference (p = 0.001) in adhesive bond strength among different groups. The highest mean adhesive bond strength (2.287 ± 0.372 MPa) was noticed in group B (25% propolis-modified GIC), followed by group A (conventional GIC 2.200 ± 0.853 MPa), and then group C (50% propolis-modified GIC 2.200 ± 0.853 MPa. There was statistically significant difference between conventional GIC and 25% propolis-modified GIC (p = 0.002) and 25% propolis-modified GIC and 50% propolis-modified GIC groups (p = 0.001). Conclusion: 25% propolis-modified GIC showed the most significant improvement in bond strength of conventional GIC. 50% propolis-modified GIC showed a deleterious effect. The 25% propolis-modified GIC seems to have the potential to improve clinical performance of restoration.

Purpose: This study compared the clinical efficacy of nanohybrid organically modified ceramic (ORMOCER) bulk-fill resin composite vs nanohybrid conventional bulk-fill resin composite in proximal compound posterior restorations. Materials and methods: In this randomized controlled clinical study, a total of 30 proximal carious lesions were restored randomly with either the intervention nanohybrid ORMOCER bulk-fill resin composite (Admira Fusion X-tra) or nanohybrid conventional bulk-fill resin composite (Grandioso X-tra). Two assessors who were blinded to the study procedures evaluated restorations at baseline (1 week), 6 months, and 12 months using the World Dental Federation (FDI) criteria, measuring functional, esthetic, and biological properties. Frequency and percentage represented the categorical data. Intragroup comparisons between interventions were calculated using the Chi-squared test. Results: The overall rate of survival of nanohybrid ORMOCER bulk-fill resin composite and nanohybrid conventional bulk-fill resin composite for proximal restorations was evaluated after 1 year. No restorations failed after 12 months in biological, esthetic, and functional properties, with no statistically significant difference in intergroup or intragroup comparisons. However, the intergroup comparison between both materials showed a statistically significant difference in color match and translucency (p = 0.0003). Conclusion: Under the study limitations, it can be concluded that nanohybrid ORMOCER bulk-fill resin composite showed comparable clinical efficacy to the nanohybrid conventional bulk-fill resin composite. Nanohybrid ORMOCER bulk-fill resin composite demonstrated slightly superior esthetic results during the one-year follow-up.

Purpose: The purpose of this study was to evaluate and compare hard and soft tissue changes around immediately loaded nonsubmerged, delayed loaded submerged, and delayed loaded nonsubmerged dental implants in partially edentulous arches. Materials and methods: A total of 30 implants were placed in 10 patients such that each patient received implants of three groups [immediately loaded nonsubmerged (group I), delayed loaded submerged (group II), and delayed loaded nonsubmerged (group III)]. The follow-up was done at 2, 4, and 6 months after implant placement. Marginal bone level was assessed by radiovisiography (RVG). The soft tissue changes were evaluated by sulcular bleeding index and probing depths. Data were analyzed statistically using the Friedman test and Wilcoxon test. Results: There was a significant increase in mean marginal bone loss from baseline to 6 months in all three groups of implants. Group I showed more mean marginal bone loss (0.87 ± 0.07 mm) when compared to group II (0.84 ± 0.12 mm) and group III (0.77 ± 0.07 mm). Sulcular bleeding decreased significantly from baseline to 6 months in all three groups. Sulcular bleeding was higher for group I (1.3 ± 0.51) when compared to group II (1.05 ± 0.61) and group III (1.22 ± 0.83). Group III showed (2.82 ± 0.31 mm) higher probing depth than group I (2.30 ± 0.49 mm) and group II (2.55 ± 0.57 mm), but the difference was insignificant. Conclusion: Immediate loaded nonsubmerged implants have more marginal bone loss and sulcular bleeding compared to delayed loaded submerged and nonsubmerged implants. Within the limitations of the study, it is suggested that posterior partial edentulism can be treated using all three techniques, considering other clinical factors.

Purpose: The purpose of this study was to compare the denture foundation surface area of maxillary and mandibular completely edentulous arches and the ratio of the two arches across different genders using digital analysis. Materials and methods: The study involved 24 edentulous patients who underwent denture construction. After pouring the definitive impressions, the dental casts were scanned using a three-dimensional (3D) scanner to produce digital replicas. These digital models were then converted into stereolithography (STL) files and imported into MeshLab software for further analysis and measurement of the maxillary and mandibular arches’ surface areas. An independent t-test was used for comparison of the surface area of arches in both genders. Results: The mean value of the maxillary surface area was 36.85 ± 4.04 cm², while the mandibular arch was 24.51 ± 4.46 cm² and the difference between both arches was statistically significant (p < 0.001). The male subjects had a larger maxillary arch surface area (37.56 ± 4.35 cm²) than the female subjects (36.13 ± 3.76 cm²), although the difference was not statistically significant (p = 0.398). Additionally, the male individuals had a larger mandibular arch surface area (25.63 ± 4.2 cm²) than female subjects (23.4 ± 4.6 cm²), and the difference was insignificant (p = 0.23). The mean ratio of the maxillary to mandibular arch surface area was 1.54 ± 0.24. Female subjects had a somewhat higher ratio (1.59 ± 0.27) than male subjects (1.49 ± 0.24). Conclusion: The study's findings show that male subjects have a larger surface area than female subjects in both arches; however, this difference was not statistically significant. The study utilized 3D scanning technology and software analysis to obtain precise surface area measurements and seems to be useful in the diagnosis and rehabilitation of traditional manual techniques.

Purpose: To evaluate and compare the efficacy of impregnation procedures on the flexural strength of polypropylene fibers reinforced polymethyl methacrylate (PMMA) denture base material. Materials and methods: Eighty PMMA samples of dimensions 65 mm × 10 mm × 3 mm were fabricated after different treatments as control group C (n = 20) and three test groups: silanized polypropylene fibers T₁ (n = 20) (fibers treated with silane coupling agent), polypropylene fibers soaked in monomer T₂ (n = 20) (fibers treated with monomer), and silanized polypropylene fibers soaked in monomer T₃ (n = 20) (fibers treated with silane coupling agent and monomer). Samples were subjected to flexural loading using a universal testing machine. Flexural strength was evaluated using the Kruskal–Wallis test and multiple analysis was done by Mann–Whitney post hoc analysis tests. Results: Mean flexural strength values obtained from different groups demonstrate that test group T₃ (silanized polypropylene fibers soaked in monomer) exhibits higher flexural strength (0.325 ± 0.021 N/mm²) followed by test group T₂ (polypropylene fibers soaked in monomer, 0.221 ± 0.009 N/mm²) and control group C (0.141 ± 0.011 N/mm²). Test group T₁ (silanized polypropylene fibers) showed the lowest mean flexural strength (0.070 ± 0.008 N/mm²) among all the study groups and the difference was statistically significant (p < 0.001). Mann–Whitney post hoc analysis showed that there was a significant difference between all groups. Conclusion: Based on the results of the present study, silanized polypropylene fibers showed the lowest mean flexural strength. When silanized polypropylene fibers soaked in monomer their flexural strength increased. In instances of anticipated fracture of dentures, impregnation procedures and addition of polypropylene fibers would be help to minimize them.

Purpose: To evaluate and compare the shear bond strength and color stability post thermocycling of two commercially available intraoral porcelain repair systems used for the repair of adhesive and cohesive fracture defects in porcelain fused to metal samples. Materials and methods: Ninety-six test samples were divided into Group I (n = 56) for shear bond strength testing and Group II (n = 40) for testing of color stability after thermocycling. Each group was further subdivided based on the repair kit used: Angelus ceramic repair kit and PrevestDenPro A.C.E ceramic repair kit for the repair of adhesive or cohesive defect fracture. Shear bond strength was tested using a universal testing machine. Color values were recorded using a spectrophotometer before and after thermocycling. Inferential statistics using one-way ANOVA test followed by Tukey's honest significant difference test was used to check difference between the subgroups. An unpaired t-test was used to compare means between two subgroups. Results: The highest mean shear bond strength was observed with PrevestDenPro A.C.E. ceramic repair kit for adhesive defects (13.39 ± 0.66 MPa; p-value < 0.001). The highest color stability was observed with Angelus ceramic repair kit for cohesive defects (with mean L, a, b values before thermocycling being 73.79 ± 2.83, 6.75 ± 0.86, and 10.73 ± 1.58, respectively, and after thermocycling 75.18 ± 2.61, 7.18 ± 0.76, and 9.45 ± 1.69, respectively, thereby giving a ΔE value of 2.44 ± 0.17; p-value < 0.001). Conclusion: From the present study, it can be concluded that for an adhesive defect, PrevestDenPro A.C.E ceramic repair kit has the better mean shear bond strength and Angelus ceramic repair kit has better color stability. For a cohesive defect, Angelus ceramic repair kit has a better mean shear bond strength and color stability. A careful consideration of the type of defect while choosing the repair system is crucial for better repair outcomes.

Purpose: To compare the retention of clasps made from cast cobalt-chromium (Co-Cr) and acetal resin in maxillary obturator prostheses for Aramany class 1 and class 2 defects with two different undercut depths (0.010 and 0.015 inch) on anterior and molar abutment teeth before and after cyclic testing. Materials and methods: Maxillary obturator prostheses for Aramany class 1 and class 2 defects were fabricated with clasps of Co-Cr and acetal resin. The study comprised four groups: group A (Co-Cr clasps, class 1 defects), group B (Co-Cr clasps, class 2 defects), group C (acetal resin clasps, class 1 defects), and group D (acetal resin clasps, class 2 defects). Each group was subdivided based on undercut depth (0.010 and 0.015 inch). The obturator prostheses were tested for retention using pull-out tests before and after 1,095 mechanical stress cycles. Statistical analysis was done using the Mann–Whitney U test. Results: For class 1 defects, cobalt-chromium clasps with 0.010 inch undercuts showed an initial retention force of 13.42 N (anterior) and 14.17 N (molar), which decreased postcycling. Clasps with a 0.015 inch undercut started with slightly higher retention, which also reduced after cycling. Acetal resin clasps, on the other hand, demonstrated lower initial retention values (e.g., 6.70 N and 7.25 N) and a significant drop postcycling. For class 2 defects, cobalt-chromium clasps performed similarly with higher initial forces than acetal resin, which again showed lower initial retention and greater reduction over time. Across both defect classes, cobalt-chromium clasps maintained superior retention compared to acetal resin. Conclusion: The study shows that both acetal resin and Co-Cr clasps provide good retention in maxillary obturator prostheses. Acetal resin is beneficial for esthetics and comfort, while Co-Cr offers superior strength and durability, making both materials valuable in different clinical scenarios.

Purpose: The purpose of this study was to evaluate the cell viability, surface characteristics, and osteoconductive potential of ovine bone graft modified with L-glutamine compared to commercial bone graft. Materials and methods: Hydroxyapatite was isolated from the femur of a goat by sintering at 360°C for 3 hours (group A). L-glutamine (HIMEDIA) was introduced into the hydroxyapatite-sintered material and named as group B. Commercially available bone graft (Bio-Oss, Geistlich) serves as the control (group C). The functional groups of the samples were characterized using a Fourier transform infrared spectrophotometer (FTIR), employing the potassium bromide pellet method. The phase composition of the groups was analyzed using X-ray diffractometer. The surface morphology and pore size of the samples were examined with a scanning electron microscope (SEM). Bone formation assay (BFA) was done to check for the optical density (OD) of samples, hence portraying the osteoconductive potential of the sample. The 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay technique was utilized to assess cell viability. Qualitative analysis was done using X-ray diffraction (XRD), FTIR, and SEM analysis. One-way analysis of variance (ANOVA) was done for the intergroup comparison of the BFA and MTT assays. A post hoc Tukey test was done to find the difference between the groups. Results: FTIR demonstrated the presence of specific functional groups in bone graft characterized with L-glutamine, like phosphate and carbonate whose presence indicates the presence of hydroxyapatite. XRD analysis highlighted the presence of hydroxyapatite in the sintered ovine bone samples confirming the suitability of these samples for a wide array of biomedical applications. Analysis of images obtained with SEM demonstrated a tightly bonded structure characterized by densely interwoven particles and distinct bioactive surface layers on the exterior of the bone graft characterized with L-glutamine. MTT assay demonstrated a significant difference among the three groups (p = 0.001), wherein group B demonstrated the highest values of cell viability. Findings for BFA indicate significant differences (p = 0.001) between the three groups, with group B demonstrating the highest values of bone formation assay, the other two groups, the ovine graft (group A) and control (group C) do not differ significantly (p = 0.911). Conclusion: L-glutamine positively affects natural bone graft growth, enhancing understanding of bone regulation. All characterizations demonstrated optimum qualities of the ovine bone graft characterized with L-glutamine, proving to be equivalent to commercially available bone graft, and could be made more economically viable for use in most clinical practices.