Purpose: The purpose of this finite element analysis (FEA) was to evaluate and compare the stresses on the terminal abutment and edentulous ridge in unilateral distal extension conditions when restored with different prosthetic options. Materials and methods: A finite element model of a unilateral maxillary edentulous arch distal to the second premolar was fabricated. The second premolar was used as a terminal abutment for three different treatment modalities, namely cast partial denture, semiprecision attachment, and flexible dentures. Three levels of loading (150, 250, and 350 N) were applied from two directions, that is, vertically (90°) and obliquely (60°), on the central fossa of the first and second molars of the prosthesis. The maximum von Mises stress distribution was recorded at two regions, that is, the terminal abutment (cervically) and the edentulous ridge. The data was divided into three groups according to the type of prosthesis. An independent t-test was used to compare the values of the three groups. Analysis of variance (ANOVA) was used to test the differences between the loading directions. Results: The highest level of stress on the terminal abutment and edentulous ridge was noted with the flexible denture (71.39 and 93.29 MPa), followed by cast partial dentures (8.63 and 3.69 MPa), and the least stress was noted with the semi-precision attachment (3.15 and 1.57 MPa, respectively). The difference in stress levels on both abutment and ridge when the flexible denture was compared with cast partial denture and semi-precision attachment was statistically significant (p < 0.05). However, the stress levels between cast partial and semi-precision attachment were not statistically significant (p > 0.05). The stress levels increased by increasing the forces from 150 to 350 N and changing the direction of forces from vertical to oblique in all three prostheses on both the abutment and edentulous ridge. Conclusion: Semi-precision attachment and cast partial denture did not depict any significant changes in stress levels on abutment teeth and edentulous ridge. However, flexible dentures show the highest stress levels. Hence, within the confines of the study, semi-precision attachment seems to be the most recommended treatment option, followed by cast partial dentures. Clinicians should limit flexible dentures to only provisional prostheses.

Purpose: The aim of the present study was to evaluate and compare the shear bond strength of feldspathic ceramic (VITA VM 9), and IPS e.max Ceram veneered on zirconia cores. Materials and methods: A total of 50 zirconia cylindrical discs measuring 10 mm in diameter and 3 mm in thickness were milled. 3M zirconia blanks were used to fabricate the zirconia cores. Half of the samples (n = 25) were layered with VITA VM 9 (group I), and the remaining samples were layered with IPS e.max Ceram (group II). The layered specimens were compressively loaded under a universal testing machine till fracture occurred. An independent samples t-test was done to compare the mean shear bond strength of two independent groups. Results: Specimens in group II, layered with IPS e.max Ceram, showed higher bond strength (1466.76 N) compared to group I, layered with VITA VM 9 (1274.12 N). The difference was significant (p = 0.047). Conclusion: Specimens layered with IPS e.max Ceram showed better bond strength than specimens layered with VITA VM 9. Hence, in patients with heavy occlusal loads, parafunction habits, multiunit restorations, or in cases of posterior rehabilitation, layering with IPS e.max Ceram can be considered.

Purpose: Commercially available stock trays do not usually fit the arch form and are relatively flat in dimensions, leading to a compromised impression and prosthesis. So, the purpose of this study was to categorize resorbed mandibular ridges according to arch width and sulcus depth and formulation of stock tray design conforming to different resorbed ridge forms. Materials and methods: Measurements on master casts of completely edentulous resorbed ridges (n = 280) were done using a digital vernier caliper. Cluster analysis of means of anterior and posterior arch width and posterior alveololingual sulcus (ALS) depth was done to categorize the extremely resorbed residual ridges for the formulation of conforming stock trays. Cluster analysis formulated three categories. Category 1 had a mean anterior arch width of 23 mm, posterior arch width of 50 mm, and posterior ALS depth of 5.5 mm. Respective dimensions in category 2 were 31, 58, and 12 mm, and in category 3 were 27, 55, and 8.7 mm. Means of arch length, ridge width, sulcus depth, and retromolar pad (RMP) angle were used to modify tray flange dimensions. One-way analysis of variance (ANOVA) for K-means and multiple Tukey honestly significant difference (HSD) tests were applied for validation of clusters/categories. Results: Significant p-values in one-way ANOVA for K-means cluster (p < 0.001) and multiple Tukey HSD test (p < 0.001) validated categorization of extremely resorbed mandibular residual ridges in the study. Mean values of other parameters were used to modify the tray flanges. The 135° angle of the RMP with residual resorbed ridge was suggested to be incorporated in trays to accommodate higher angles too. Conclusion: Use of the formulated stock trays, will improve their adaptation to the resorbed mandibular edentulous ridges and hence the primary impression making, which will provide a strong foundation for a successful final complete denture in such patients.

Purpose: The purpose of the study was to evaluate and compare the peel bond strength of a room temperature vulcanizing (RTV) maxillofacial silicone bonded to three different high-impact heat-cure acrylic resins. Materials and methods: A total of 80 standardized rectangular specimens of dimensions 75 × 10 × 6 mm were fabricated. The specimens were categorized into four groups (n = 20 each) as group I—conventional heat-cure acrylic resin (Trevalon) and three brands of high-impact heat-cure acrylic resins (group II: Lucitone 199, group III: Acralyn H, and group IV: Acryl Hi). Each standardized specimen consisted of a rectangular acrylic component to which silicone was bonded using a primer. Peel bond strength between the acrylic and silicone was measured using a universal testing machine. Kruskal–Wallis H test was performed to compare the peel bond strength among all groups, followed by Dunn post hoc test to find the significant difference for pairwise comparison. Results: Standardized test specimens belonging to group II (Lucitone 199), bonded to RTV maxillofacial silicone, showed significantly (p = 0.013) greater peel bond strength (0.0372 ± 0.013 MPa) among all the groups. The test specimens of group III (Acralyn H, 0.0213 ± 0.007 MPa), group I (Trevalon, 0.0185 ± 0.009 MPa), and group IV (Acryl Hi, 0.0148 ± 0.007 MPa) showed peel bond strength to RTV silicones in decreasing order. Conclusion: The high-impact heat-cure acrylic resin (Lucitone 199) had significantly higher bond strength to maxillofacial silicones with the use of a primer than other acrylic resins used in the study. The other two brands of high-impact heat-cure acrylic resins showed comparable peel bond strength to that of conventional heat-cure acrylic resins. Therefore, high-impact heat-cure acrylic resins can be used as alternatives to conventional heat-cure acrylic resins in conjunction with RTV silicones in the fabrication of maxillofacial prostheses.

Purpose: The purpose of the present study was to find the correlation between gingival crevicular fluid (GCF)/peri-implant crevicular fluid (PICF) alkaline phosphatase (ALP) levels and implant stability in controlled diabetic patients. Materials and methods: In this study, 30 controlled diabetic patients needing implants in the mandibular posterior region were divided into two groups, that is, group I—patients with normal serum ALP and group II—patients with raised serum ALP. Each individual was rehabilitated with one implant following a nonfunctional immediate loading protocol. Implant stability in each individual was assessed by measuring implant stability quotient (ISQ) values. GCF/PICF samples were collected to evaluate the level of ALP. Both parameters were evaluated at baseline, 1, and 3 months postimplant placement, and the resulting values were compared using analysis of variance (ANOVA) and post hoc Bonferroni test within the group, and unpaired t-test was used for comparison between the two groups. The correlation between the two parameters was determined using Pearson's correlation coefficient (r) test. Results: In group I patients with normal serum ALP, the mean ALP in GCF/PICF and ISQ values at baseline was 685.19 IU/L and 72.53; at 1 month, were 608.08 IU/L and 68.73; at 3 months, were 766.26 IU/L and 79.33, respectively. In group II patients with raised serum ALP, the mean ALP in GCF/PICF and ISQ values at baseline were 1042.75 IU/L and 72.40; at 1 month, were 932.75 IU/L and 65.07; at 3 months, were 1111.73 IU/L and 76.80, respectively. A significant difference was seen in GCF/PICF ALP values between the two groups, whereas nonsignificant difference was observed in ISQ values between group I and group II. Conclusion: No direct correlation was found between implant stability and GCF/PICF ALP in patients with normal serum ALP, and a negative correlation (with an increase in GCF/PICF ALP values, there was a corresponding decrease in the ISQ values) was found in patients with raised serum ALP at different time intervals.

Purpose: The purpose of this in vitro study was to evaluate the respective color stability of modern composite resins designed for esthetic restorations when continuously exposed to various beverages. Material and methods: A total of 60 disk-shaped specimens made out of three composite materials (Omnichroma, Beautifil-Bulk restorative, and G-aenial) were used. A total of 20 specimens measuring 10 mm in diameter and 1 mm in thickness were made from each composite resin. After dry storage at 37°C for 24 hours in an incubator, the initial color was assessed by a calibrated spectrophotometer. Test specimens were immersed in four staining solutions, and the control group was dry-stored. All specimens were kept in an incubator at 37°C for 28 days. After 28 days, spectrophotometric measurements were again performed to determine the color changes. One-way analysis of variance (ANOVA) was used for the comparison of each beverage among the three groups to find the significant difference. Results: Omnichroma material exhibited less color change as compared to Beautifil-Bulk restorative and G-aenial composites. The highest color change measured against a white background was observed for Beautifil-Bulk in coffee (p = 0.001), while the least staining was observed for Omnichroma in tea (p = 0.003). The highest color change measured against a black background was observed for Beautifil-Bulk in coffee (p = 0.001), while the least staining was observed for G-aenial in coffee (p = 0.001). Conclusion: All three types of composites displayed color changes after immersion in tea, coffee, orange juice, and cola. Omnichroma showed higher color stability than Beautifil-Bulk restorative and G-aenial.

Purpose: The objective of this study was to assess the fracture resistance of functionally graded monolithic zirconia with different nanoparticles in three-unit fixed dental prostheses (FDPs) after undergoing thermal and mechanical aging. Materials and methods: A total of 32 three-unit monolithic zirconia prostheses were machined and randomly assigned to four groups (n = 8 each) as Group A—control group (without any nanoparticle), Group B—titania sol group, Group C—silica sol group, and Group D—silica and titania nano-sol group. Grading with nanoparticles was carried out on presintered monolithic zirconia and then was sintered. Fixed prostheses were exposed to thermocycling for 5–55°C for 10,000 cycles. The long-term clinical performance of monolithic zirconia was assessed by quasi-static fracture strength of 0–300 N for 1,00,000 cycles. After following loading conditions, prostheses were loaded until fracture. Fracture mode and evaluation of nanoparticles were seen under a field-emission scanning electron microscope (FE-SEM). Energy dispersive spectroscopy (EDS) was done to find an elemental composition of nanoparticles in zirconia. Weibull's modulus implies the reliability of material for each of the four materials. Kruskal–Wallis analysis of variance (ANOVA) followed by a post hoc test done for the between-group differences in the maximum load-bearing capacity of the four groups. Results: Significant variance (p = 0.001) in the fracture resistance of three-unit FDPs after mechanical and thermal cycling was observed. The fracture resistance of the control group A (703.60 N) was significantly lesser than that of the titania sol group B (1031.35 N) and silica and titania nano-sol group D (1094.74 N). Weibull moduli values of all four groups are as follows in descending order groups D > A > B > C. Conclusion: Functional grading of monolithic zirconia with silica and titanium dioxide nanoparticles can increase the fracture resistance of three-unit FDPs after aging. The addition of titanium to zirconia has been shown to increase the Weibull modulus, which corresponds to a higher level of homogeneity of the material and more excellent reliability as a structural material.

Purpose: To perform a systematic review that provides an overview of the current literature on the most efficient surface treatment method for repairing three-dimensional (3D) printed dentures compared to conventional dentures and computer-aided design/computer-aided manufacturing (CAD/CAM) milled dentures. Materials and methods: The review followed the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) guidelines. Electronic searches were done via Ovid, PubMed, ScienceDirect, Scopus, and Web of Science for studies reporting on denture base repair with surface treatment. Inclusion criteria were the English language with full text and studies that included surface treatment. Exclusion criteria were studies that did not assess the performance of surface treatment in denture repair. A quality assessment and selection of full-text articles were performed according to Consolidated Standards of Reporting Trials (CONSORT). Results: A total of 531 articles were initially identified and screened. After applying inclusion and exclusion criteria, 14 articles were selected for the final analysis. Around 10 of the included studies utilized three-point flexural bending tests to test the flexural strength (FS) of the repaired samples. Four studies used the shear test. Around 12 studies used conventional resins and two studies used 3D-printed denture base resin specimens. Nearly 11 studies performed posttest analysis. Conclusion: Studies have shown various promising enhancements in repair strength with both mechanical and chemical surface treatment. However, more research is required specifically on 3D printed and CAD/CAM dentures and to compare mechanical and chemical surface treatments or combinations of both, for it to become a more established treatment option.

Esthetic crown lengthening followed by ceramic veneers can be performed for a patient with a gummy smile and defective teeth. However, definitive ceramic veneer restorations can be achieved after 3–6 months of surgery. During the healing period, provisional splint veneers for esthetic prototypes with conventional technique may create uncleanable interproximal areas, which leads to inflammation and interference with the healing process. This case report demonstrates a workflow of an injection layering technique for a patient with a gummy smile and discolored and worn teeth. At the early stage of esthetic crown lengthening, flowable composite resins are injected into transparent silicone index fabricated from a diagnostic wax-up, including cut-back and internal stain to mimic the internal characterization of the incisal edge of natural tooth color to create a long-term provisional nonprep veneer. The use of this technique with a simple and predictable workflow allows patient for function and evaluates phonetics, lip support as well as a highly esthetic outcome.