The implant evolution has become a "restorative driven" field, and it is therefore important to know the designing principles of abutments and its connection to the implants and its rationale for use in clinical practice. The key is to have an optimum selection and designing of the implant to meet the implant position and angulation in the clinical scenario. A search was conducted both manually and electronically to find terms that included dental implants, dental abutments, custom abutments, cast abutments, abutment-implant interface, emergence profile, soft tissue profile, provisional restoration, CAD/CAM abutments, abutment innovations, abutment designing, abutment selection, and abutment materials. A total of 4332 English titles were obtained in various combinations and were repeated and duplicated due to multiple searching. Proper short-listing of the articles was done and a comprehensive review was formulated. This review article highlights various methods and rationale behind selection, designing of various abutments, its influence on emergence profile, and the newer advances and trends that have emerged in the field of implant dentistry.

Purpose: The aim of this in vitro study was to determine the color changes of four different restorative materials after exposing these materials to two different bleaching agents. Materials and Methods: In this study, bleaching agents were applied to a low-fusing porcelain (VITA VM9), heat-pressed glass ceramics (IPS Empress Esthetic), and two types of composites (Clearfil Majesty Esthetic and Clearfil Photo Posterior). Twenty disc-shaped specimens were fabricated (with a diameter of 10 mm and a thickness of 2 mm) from each material (n0 = 10). The initial color changes were measured using a spectrophotometer. The first set of specimens were bleached with 10% hydrogen peroxide (HP) for 1 h daily for 10 days. Another set of specimens were bleached with 40% HP bleaching gel for two consecutive applications for 20 min each. The data were analyzed statistically by using two-way analysis of variance (ANOVA) and post hoc Tamhane's T2 tests ( P < 0.05). Results: The mean color change value (ΔE) for Clearfil Majesty Esthetic was significantly higher than the value for VITA VM9 groups, treated with the 10% HP. In addition, the values for Clearfil Photo Posterior were significantly higher than the values for Clearfil Majesty Esthetic, IPS Empress Esthetic, and VITA VM9 groups treated with the 40% HP (P < 0.05). The comparative evaluation of bleaching agents on the color change of materials revealed that the differences between the bleaching agents were significant for the Clearfil Photo Posterior groups (P < 0.05). Conclusion: The effects of bleaching agents should be known and applied consciously when restorative materials (especially polymer-containing restorative materials) are present.

Introduction: The aim of this study is to determine the shear bond strength (SBS) of ceramic brackets bonded to three different porcelain surfaces. Materials and Methods: A total of 36 porcelain crowns were used in this study. Porcelain crowns were allocated to the three groups as follows: Conventional porcelain-fused-to-metal crowns, IPS e.max ceramic crowns, and porcelain-fused-to-zirconia crowns. Porcelain surfaces were etched with 9.6% hydrofluoric acid and rinsed with a water/spray combination. Then, ceramic brackets were bonded with a light-cured composite resin. All the specimens were stored in distilled water at 37°C for 24 hours and thermocycled and loaded into a universal testing machine for testing. Any adhesive that remained after debonding was assessed and scored according to the modified adhesive remnant index (ARI). Statistical Analysis: One-way analysis of variance (ANOVA) and Tukey's test were used to compare the SBS of the groups. The Chi-square test was used to determine the ARI scores among the groups. Results: No statistically significant difference between the ARI scores for the three types of crowns was observed. In the conventional porcelain-fused-to-metal crown group (7.09 MPa), the lowest values of bond strength were obtained. Although similar values of bond strength were found in the IPS e.max ceramic crown (8.60 MPa) and porcelain-fused-to-zirconia crown (8.93 MPa) groups, the statistically significant differences in values of shear bond strength have observed between the other groups. Conclusions: SBS of ceramic brackets bonded to different porcelain surfaces may produce different results due to the type of porcelain crown.

Background: The objectives of this study were to evaluate the frequency of complete edentulism among rural and urban population of Udaipur district of Rajasthan who visited at a department of prosthesis at a university for the 1 ^st time. Materials and Methods: A cross-sectional study using the systematic cluster sampling method was used to select the study sample of 524 elderly men and women. Data were collected using questionnaires and oral examination. Data were statistically analyzed using a Chi-square test. Results: Nearly 52.3% and 47.8% of the rural and urban females were completely edentulous in the age group of 30-50 years and 51-70 years. 55.1% and 53.8% of urban and rural males were completely edentulous in 51-70 years of age groups. Conclusions: It is essential to identify feasible strategies to provide primary dental health education and treatment to all rural and urban elderly in the future. We suggest community dental health services as a general health need of the elderly rather than a special health need of the community.