Tania Sethi

Three-Dimensional Evaluation of Alveolar Bone and Soft Tissue Dimensions of Maxillary Central Incisors for Immediate Implant Placement: A Cone-Beam Computed Tomography Assisted Analysis.

Introduction:This study explored the relationship between the thickness of bone and soft tissue along the labial and palatal aspect of maxillary central incisors. The influence of overall socket width, labiopalatal positioning of the incisor on the bone, and soft tissue thickness were also investigated. Materials and Methods:This study used cone-beam computed tomography of 150 patients to determine labial, palatal soft and hard tissue thickness, labiopalatal (B-P) socket width and corelated the same to the labiopalatal positioning of maxillary central incisors. Results:Mean (SD) thicknesses of the labial soft tissue at cervical (C), midroot (M), and apical (A) locations and the corresponding bone thicknesses were 1.07 (0.28), 0.987 (0.27), 1.240 (0.41), and 0.928 (0.39), 0.894 (0.52), 1.57 (0.88), respectively. Similarly, palatal soft tissue and bone thicknesses at locations C, M, A were 1.807 (0.66), 1.557 (0.62), 1.639 (0.66), and 1.679 (0.62), 3.439 (1.28), 6.038 (1.63), respectively. Mean (SD) thicknesses of the B-P socket width at location C was 8.047 (0.963). Conclusions:There is a positive correlation between the labial and palatal bone and corresponding soft tissue thickness, between thickness of the labial bone and the labiopalatal thickness of the alveolar socket. No correlation was observed between the thickness of the labial cortical bone and the labiopalatal positioning of the tooth.

Reduction of excess cement during cementation of implant-retained crowns: A clinical tip

The osseointegrated implants has changed the treatment methods of edentulous patients. This technical note presents a simple chair side technique to minimize the overflow of cement at the time of cementation with the use of a custom-made abutment replica during the placement of an implant retained crown.

Evaluation of the effect of ultraviolet stabilizers on the change in color of pigmented silicone elastomer: An in vitro study

Aim and Objective: To compare and evaluate the effect of ultraviolet (UV) stabilizers (Chimassorb 81 and Uvinul 5050) on the color change of pigmented elastomer. Materials and Methods: Two pigments - Red (P112 Brilliant Red) and Yellow (P106 Yellow) and two UV stabilizers Chimassorb 81 and Uvinul 5050 were studied. A total of six groups of 10 samples each were fabricated using a combination of the above colors and stabilizers: Group A1 - Red control, Group A2 - Red + Chimassorb 81, Group A3 - Red + Uvinul 5050. Group B1 - Yellow control, Group B2 - Yellow + Chimassorb 81, Group B3 - Yellow + Uvinul 5050. All samples were subjected to ageing in an accelerated weathering chamber (Weather-Ometer). Color values L, a, and b were measured at 500 and 1000 h for all samples before and after weathering and change in color (Delta E) was calculated. Results: All groups showed a significant color change. At 500 h, Chimassorb 81 showed a statistically significant lesser change in both colors (red - 3.66 and yellow - 2.8) compared to their control groups (red - 5.19 and yellow - 4.9). At 1000 h, both UV stabilizers showed lesser color change (A2 - 5.49, B2 - 4.28, A3 - 7.47 and B3 - 4.09) as compared to their respective control groups (A1 - 9.57 and B1 - 5.91). Overall, the change in the color with Group A was more than Group B. Conclusion: Addition of UV stabilizers helped the reduction of color change. Chimassorb 81 showed a greater reduction in color change in both colors consistently at 500 and 1000 h.

Fabrication of a custom ocular prosthesis.

Defects of the eye may follow removal of a part of or the entire orbit. This results in the patient becoming visually, esthetically and psychologically handicapped. Restoring the defect with a silicone- or acrylic-based prosthesis not only restores esthetics but also gives back the lost confidence to the patient. This is a case report of a patient with a ‘pthisical eye’ and details the steps in fabrication of an ocular prosthesis. Particular attention has been given to the laboratory process in this technique to minimize the residual monomer content in the artificial eye.

Change in color of a maxillofacial prosthetic silicone elastomer, following investment in molds of different materials

Purpose: In the authors′ experience, the color of silicone elastomer following polymerization in molds made of gypsum products is slightly different from the color that was matched in the presence of the patient, before the silicone is packed. It is hypothesized that the investing materials and separating media have an effect on the color during the polymerization process of the silicone. Materials and Methods : This study compares and evaluates the change in color of silicone elastomer packed in three commonly used investing materials - Dental stone (white color), dental stone (green color), and die stone (orange color); coated with three different separating media - Alginate-based medium, soap solution and a resin-based die hardening material. Pigmented silicone samples of dimensions 1.5 cm × 2 cm × 0.5 cm were made from the elastomer in the above-mentioned mold materials using combinations of the mentioned separating media. These served as test group samples. Control group samples were made by packing a mix of the same pigmented elastomer in stainless steel molds. The LFNx01, aFNx01, bFNx01 values of the test and control group samples were determined using a spectrophotometer. The change in color (Delta E) was calculated between the control and test groups. Results: The mean L, a, b values for the control group were, 31.8, 26.2, and 36.3, respectively. Average values of change in color (Delta E) for samples packed utilizing alginate-based medium, die hardener, and soap solution, respectively in white dental stone (2.70, 2.74, and 2.88), green dental stone (2.19, 2.23, 2.42), and orange die stone (3.19, 2.72, 2.80) were tabulated. Conclusion: Among the investing materials studied, die stone showed the most color change (3.19), which was statistically significant. Among the separating media, die hardener showed the least color change (2.23). The best combination of an investing material and separating media as per this investigation is a dental stone (green) and alginate-based separating medium.

Evaluation of the effect of UV stabilizers on the change in colour of a silicone elastomer following ageing by three different methods -An In-Vitro Study

Aim and objective-To compare and evaluate the effect of UV stabilizers (UV absorbers and Hindered Amine Light Stabilizers-HALS) on the colour change of a commonly used silicone elastomer subjected to ageing by three different methods. Materials and methods4 groups of 30 samples each were studied; Group A-Control, Group B-Silicone+ UVA (Chimassorb 81),Group CSilicone+ HALS (Uvinul 5050) and Group D-Silicone + Combination (UVA+ HALS) (Chimassorb 81+Uvinul 5050). Each group was further divided into groups of 10 samples each based on the method of ageingaccelerated weathering chamber (Weather-Ometer), artificial perspiration and a cleansing agent. CIE Lab colour values L*, a* and b* were measured for all samples before and after weathering and change in colour (Delta-E) was calculated. One-way ANOVA was applied to compare the mean values of the 4 groups and the Post Hoc Tukey test was carried out to compare between 2 groups. ResultsAll groups showed a significant colour change. For Group A the colour change (average Delta E) for accelerated weathering, artificial perspiration and cleansing agent was 1.479, 0.617 and 0.62 respectively. Similarly, for Group B it was 1.109, 0.509 and 0.507; for Group C it was 1.866, 0.652 and 0.997 and for Group D it was 1.303, 0.829 and 1.033 respectively. UVA (Chimassorb 81) showed the least change consistently in all 3 types of ageing. Conclusion-Addition of UV stabilizer Chimassorb 81 showed a reduction in colour change of the silicone elastomer. Following studies on the effect of these additives on the physical properties of elastomers has shown that they can have a potential use in maxillofacial prosthetic rehabilitation.

Access to Abutment Screw in Cement Retained Restorations: A Clinical Tip

Abutment screw loosening has been reported to be the most common prosthetic complications occurring in screw retained as well as cement retained implant restorations. Different methods to treat this issue have been reported in the literature so far; however these have their own short-comings. Retrievability of an implant restoration intact becomes a clinical challenge when the restoration is cement retained especially with an angulated abutment. This technique is aimed at accurately determining the position of the abutment screw in 3 dimensional relationships using a vacuum formed clear stent. This technique can be used as a viable protocol for management of screw loosening in cement retained implant restorations.