Purpose: The objective of this study was to investigate the clinical effect of guided bone regeneration (GBR) combined with modified large-head tenting screws in the reconstruction of a mandibular advanced vertical bone defect. Materials and methods: Patients who met the inclusion criteria were included in the study. Deproteinized bovine bone was filled alone underneath the large-head tenting screws as grafting material, and the collagen membrane was covered as a barrier. About 10 months after surgery, cone-beam computed tomography (CBCT) was employed to access linear and volume changes in the augmented area, and biopsy was harvested for micro-computed tomography (micro-CT) and histological analysis during staged-implant placement. Implant survival rate and surgical-related complications were recorded. Descriptive analysis was done using Statistical Package for the Social Sciences (SPSS) software. Results: From May 2017 to September 2021, a total of 20 patients fulfilled the inclusion criteria and received large-head tenting screw-enforced GBR. There were no postoperative complications or adverse events that occurred during the healing phase. Approximately 10 months after surgery, the average linear vertical bone gain was 5.76 ± 3.14 mm (0.05–11.77 mm), with the mean linear horizontal width gain being 3.42 ± 2.56 mm (0.56–8.91 mm). The bone volume/total volume (BV/TV) and bone mineral density (BMD) were 27.55 ± 4.59% and 0.28 ± 0.05 g/cm³, respectively. Histological analysis of the regenerated alveolar bone revealed that the new bone percentage was 25.95 ± 6.07% (17.4–36.7%), and the percentage of the remaining scaffold was 30.95 ± 3.79% (23.1–37.0%) at 10 months, postoperatively. All implants were placed according to preoperative planning, and no implants failed after the healing phase. Conclusion: With the limitations of the study, the combination of large-head tenting screws with deproteinized bovine bone and collagen membrane appears to be a promising and exceptional technique in the reconstruction of advanced vertical bone defects in the posterior mandible.

Purpose: This in vitro study was carried out to compare the wear of opposing natural teeth caused by zirconia, resin nanoceramic restorations, and polymer-infiltrated ceramic network (PICN). Materials and methods: A total of 12 disk-shaped samples measuring 10 × 2 mm were milled from each of the following blanks–Zirconia disc (3M™ Lava^™ Plus), Lava^™ Ultimate computer-aided design and computer-aided manufacturing (CAD/CAM) blocks, and VITA ENAMIC^® CAD/CAM blocks. The samples were grouped as group I—zirconia (n = 12), group II—resin nanoceramics (n =12), and group III—PICN (n = 12). A total of 36 freshly extracted maxillary premolars were collected and allocated to three groups (n = 12 each). The extracted teeth were weighed and scanned for prewear. The disc samples were subjected to a two-body wear test against the natural teeth in a two-body wear machine for 10,000 cycles, and readings were recorded. The teeth were again weighed and subjected to postwear scans. The one-way analysis of variance (ANOVA) was done to find the significant difference among groups, and post hoc Bonferroni's test was done for intergroup comparisons. Results: The results revealed that there was a statistically significant difference (p = 0.001) in all three groups. The maximum amount of wear was seen with zirconia (0.2912 ± 0.151 mm) followed by resin nanoceramic (0.1345 ± 0.017 mm) and PICN (0.1233 ± 0.007 mm). The maximum amount of weight loss was seen with zirconia (0.0100 ± 0.0048 gm), followed by resin nanoceramic (0.0037 ± 0.0037 gm), and the least amount of weight loss was seen in PICN (0.0017 ± 0.0009 gm). Conclusion: PICN displayed the least volumetric loss of the opposing natural teeth (both according to the weight and change in linear dimension), followed by resin nanoceramic and zirconia. In the case of bruxers, hybrid ceramics can be considered good alternatives to zirconia.

Objectives: The aim of the study was to categorize the partially edentulous arches based on Kennedy's classification and to explore the association of partial edentulism with gender, age, and reason for teeth loss among patients in a tertiary care center in Nepal. Materials and methods: A cross-sectional descriptive study was conducted among patients visiting the Department of Prosthodontics, Tribhuvan University Dental Teaching Hospital, Kathmandu, Nepal, for prosthetic replacement of missing teeth from May 2021 to July 2021. The patterns of partial edentulism were recorded by visual examination, and Kennedy's classification was used to categorize partially edentulous arches. The self-administered proforma was used to record the sociodemographic data and pattern of partial edentulism. Data were analyzed using Statistical Package for Social Science version 17 (SPSS) (SPSS version 17). Descriptive statistics were calculated, and the association between the variables was estimated using the Chi-squared test. Results: A total of 81 (47.65%) patients had edentulism on the maxillary arch only, 5 (2.94%) had edentulism on the mandibular arch only, and 84 (49.41%) had edentulism on both arches. Kennedy's class III was the most common partial edentulism in both maxillary and mandibular arches, which was 83 (50.30%) and 40 (44.94%), respectively. The patients were divided into three groups according to their age; 18–35 years (group I), 36–55 years (group II), and 56 years and above (group III). Kennedy's class III was the most common partial edentulism among groups I and II, whereas Kennedy's class I was the most common partial edentulism among group III in both the arches. Conclusion: The present study showed that the most prevalent partial edentulism was Kennedy's class III. There is an increase in classes I and II of the Kennedy classification and a decrease in classes III with an increase in age.

Purpose: The purpose of this finite element analysis (FEA) study was to investigate stress distribution in bone distal to the implant by varying the attachments, implant configurations, and biomaterials in a mandibular implant-retained overdenture (IRO). Materials and methods: Abutments were designed in four groups as per the geometry (ball and locator attachment) and biomaterial used for fabrication [grade IV titanium (Ti) and polyether ether ketone (PEEK)]. Eight finite element models were generated by varying either the attachment, material, and/or number of implants in each model. A force of 100 N was subjected to the implant assemblies of each model and von Mises stresses (VMS) and stress distribution patterns were evaluated and comparatively analyzed. In this in vitro study, the models were tested (n = 8) at axial (0°) angulation of force application. Results: The maximum VMS of the order of 7.27 MPa were observed in the cortical shell of the distal bone in two implant models using locator attachments as opposed to 5.89 MPa observed in the three-implant model using ball attachments. High stresses were concentrated in one location in the implant-abutment connection area, especially in the models designed with PEEK locators that totaled 7.36 MPa, in both two-implant and three-implant configurations. Conclusion: Finite element analysis (FEA) study confirmed that the three-implant configuration displayed a better stress profile when compared to two-implant specimens. Biomechanically, the most favorable combination was a three-implant configuration using PEEK ball attachments.

Purpose: Evaluation and comparison of aging resistance and fracture load of porcelain-fused metal (PFM) crowns and high-speed sintered zirconia crowns. Materials and methods: Two maxillary first molar typodont teeth were taken, and tooth preparation was performed for both zirconia (all ceramic) and PFM (metal-ceramic) crowns. These prepared teeth were scanned and milled with stainless steel to prepare dies. A total of 28 metal dies were prepared (14 zirconia and 14 PFM). These were further divided into degraded and undegraded groups (seven each) in both zirconia and PFM groups. An accelerated aging test was performed on the degraded group in the drying oven, and a fracture test was performed with a universal testing machine (UTM). Aging resistance was determined with the scanning electron microscope (SEM). A one-way analysis of variance (ANOVA) test was performed to find the difference in fracture loads among the degraded and undegraded groups statistically. Tukey's post hoc analysis was used to find the pairwise mean differences with all the tested groups. Results: Fracture resistance of PFM crowns was more with a mean fracture load of 2857 ± 114 N when compared to the monolithic zirconia crowns, which are sintered under high speed with a mean of 3528 ± 153 N. Aging resistance was observed in the SEM images, with comparable changes seen in the studied groups. The ceramic layer of the PFM crown shows well-scattered granules in the undegraded crown, and the degraded crown shows surface roughness with less granular size and worn-out areas. The metallic portion of the PFM crown showed sharp, well-defined crystals in the undegraded group and rounded crystalline edges in the degraded group. Conclusion: The fracture resistance of porcelain PFM is more when compared to the high-speed sintered monolithic zirconia crowns. Degradation of crowns decreases fracture resistance. SEM analysis shows as age increases; crowns are more likely to fracture.

Purpose: The purpose of this in vitro study was to compare the effects of different milling speeds on the marginal adaptation and roughness of zirconia crowns fabricated using the chairside computer-aided manufacturing (CAM) process. Materials and methods: A zirconia crown preparation of a maxillary central incisor was scanned and designed using an intraoral scanner and a chairside computer-aided design (CAD) system (CEREC Omnicam and CEREC SW 4.6.1, Dentsply Sirona, York, Pennsylvania, United States of America). A total of 20, 4% yttria-stabilized tetragonal zirconia polycrystalline (4Y-TZP) crowns (Chairside Zirconia, 3M, St Paul, Minnesota, United States of America) were dry milled through the fast (FA; n =10) and fine (FI; n = 10) milling modes using a four-axis milling machine (CEREC MC XL, Dentsply Sirona, York, Pennsylvania, United States of America). Times taken for milling and sintering were measured. After the sintering process, the roughness average (Ra) of the labial surfaces of zirconia crowns was measured. Each sample was temporarily cemented on a cobalt-chromium (Co-Cr) copy die to measure the marginal discrepancy (MD) using a scanning electron microscope at 65–75× magnification. The statistical analysis was done using an unpaired two-sample t-test to evaluate if there was any significant difference in milling times and surface roughness of FA and FI groups. Mann–Whitney U test was performed to assess any significant difference in marginal adaptation between FA and FI groups. Results: The milling time for the FA group was significantly shorter than the FI group (p < 0.001). The Ra values (µm) for the FA group were also significantly higher than the FI group (p < 0.001). However, both groups had an Ra level greater than the clinically acceptable range of 0.2 µm. There was no significant difference in the marginal adaptation of FA and FI groups (p = 0.436). Both FA and FI groups showed MD within the clinically acceptable ranges (MD < 100 µm). Conclusion: The FA milling option available in CEREC MC XL produced zirconia crowns with significantly rougher surfaces within a shorter period of time as compared to the FI milling mode. However, the roughness values in both groups were clinically unacceptable after milling, which should be improved with further polishing. Conversely, the marginal adaptation of the crowns produced by both speed modes were within the clinically acceptable range, with no significant difference.

Purpose: This in vitro study correlated the effect of venting in porcelain fused to metal (PFM) crowns on seating discrepancy, cement thickness, and microleakage. Materials and methods: Thirty freshly extracted non-carious molars were disinfected with chloramine T and prepared for PFM crowns. The prepared teeth were divided into three groups (n = 10 each); non-vented control group, occlusal vent group, and lingual vent group. Crowns were fabricated using direct metal laser sintering (DMLS) technology and cemented with resin-based cement. The discrepancy, microleakage, and cement thickness were evaluated under a stereomicroscope. The specimens were subjected to thermal cycling of 5000 cycles, followed by immersion in 2% methylene blue dye. The tooth was sectioned buccolingually to determine cement thickness and microleakage using Tjan's 5-point scale. One-way analysis of variance (ANOVA) was done to find the significant difference among the groups. The post hoc Tukey test was done for intergroup analysis of cement thickness and microleakage. Intergroup comparison for seating discrepancy was done using the Mann–Whitney U test and further correlation was investigated using Pearson's correlation test. Results: The vented groups showed statistically significant differences (p < 0.05) with better seating, less microleakage, and optimum cement thickness compared to the non-vented groups. Mean seating discrepancy was the lowest for occlusal vent group II (11.13 ± 10.13 µm), followed by lingual vent group III (25 ± 18.47 µm), and highest for control group I (104.28 ± 28.78 µm). The mean microleakage score was lowest for lingual vent group III (0.9 ± 0.46), followed by occlusal vent group II (1.1 ± 0.45), and highest for the control group I (3.3 ± 0.91). Mean cement thickness values were lowest for occlusal vent group II (110.4 ± 9.96 µm), followed by lingual vent group III (110.6 ± 16.82 µm), and highest for control group I (199.01 ± 25.79 µm). A nonsignificant difference was found between the two vented groups for all three parameters (p > 0.05). Conclusion: Both the vented groups show less seating discrepancy, less microleakage, and less cement thickness as compared to the non-vented control group. A high, positive, and significant correlation was observed between microleakage and cement thickness for all three groups.

Apart from the common complication of sinus membrane tear, sinus-related pathologies, sinusitis, or infections pose a challenge for implant placement. This case report presented sinus augmentation with simultaneous implant placement in infected maxillary sinus after cyst drainage with a follow-up of 2 years. A direct sinus lift was performed for the placement of implants. Upon opening the window with the piezosurgical unit, the sinus was drained, and fluid was sent for culture. The implants were placed and the graft was filled in the cavity. The patient showed good tolerance towards the procedure and did not show any complications after over a period of 2 years follow-up.

Loss of the eye can occur due to congenital defects, developmental agenesis, traumatic exposure, or tumors resulting in significant physical, psychological, and emotional problems. In such cases, prosthetic rehabilitation can be opted for using prefabricated eye shells or custom-made ocular prostheses. Adaptation of prefabricated eye shells usually does not match the patient's anatomy of the socket well. Custom-made ocular prosthesis offers the best result as they allow recording and replicating of accurate details of eye socket enhancing the fit of the prosthesis and esthetics. The present case report describes the prosthetic rehabilitation using customized impressions, the custom three-dimensional (3D) orientation of wax pattern, and the characterization of the ocular prosthesis in a patient with a postevisceration ocular defect.