Comparative Evaluation of Stress Distribution around Various Threaded Implants with and without Platform Switch: A 3-D Finite Element Analysis.

AIM: The purpose of this study was to compare the stress distribution around various thread design implants with or without platform switching in the maxillary posterior region. MATERIALS AND METHODS: Stress-based performances of four different thread design implants (single, double, triple, and asymmetric thread design each with or without platform switching) were analyzed by the three-dimensional finite element method under a static load of 100 N at 15° oblique direction buccolingually at the central portion of the abutment. A geometric model of the posterior maxillary segment (first molar region) with an implant and abutment was modeled using the CATIA V5R19 software. Type IV bone quality was approximated and complete osseous integration was assumed. RESULTS: The von Mises stresses recorded around the neck of the fourthread design implants without platform switching were greater than the platform switching variety. The single-threaded implant with platform switching showed the lowest amount of von Mises stress. Additionally, total displacement or micromovement of single, triple, and asymmetric thread implants with platform switching was found to be greater than the without platform switching variety. Further, the total displacement of the single-threaded implant without platform switching was lowest. CONCLUSION: Implant surface design, platform switching, and site of placement affect load transmission mechanisms. Due to low crestal resorption, single thread design with platform switching is preferred. The success of an implant in the maxillary molar region is more challenging in terms of the density of bone and the worst load transfer mechanism. With the right kind of implant surface design selection, this can be reduced to a great extent by the preservation of crest of the ridge. CLINICAL SIGNIFICANCE: Crestal bone resorption following implant placement is an important issue. An optimum implant design with a single thread having a platform switch could compensate for this issue to a great extent.

Efficacy of Ozonised Water and 0.2% Chlorhexidine Gluconate in the Management of Chronic Periodontitis when Used as an Irrigant in Conjugation with Phase I Therapy.

AIM: To evaluate the efficacy of irrigation of periodontal pockets by using ozonated water and 0.2% chlorhexidine (CHX) gluconate as adjuncts to scaling and root planing in the management of chronic periodontitis. MATERIALS AND METHODS: For the present study, 20 patients in the age group of 30-60 years, suffering from chronic periodontitis presenting with at least one site with an almost similar pocket depth of 4-6 mm in both the quadrants of maxillary arch was taken. Irrigation was done after 2 weeks of scaling and root planning on the same day with ozonated water and 0.2% chlorhexidine gluconate for two and half minutes. The clinical parameters like gingival index, probing pocket depth (PPD) and clinical attachment level (CAL) were recorded for both the groups at the baseline visit.They were subsequently recalled after 4 weeks and 3 months interval from the baseline visit. Data thus collected was compiled and put to statistical analysis. RESULTS: The present study showed significant results in both the groups with regards to the improvement in the clinical parameters. When comparison was made between the two groups, ozonated water showed slightly better improvement than the chlorhexidine group. However, a statistically significant difference was seen only with Plaque score. CONCLUSION: Subgingival irrigation with ozonized water is beneficial than present conventional therapeutic modalities. Ozonated water restricts the formation of dental plaque and reduces the number of subgingival pathogens thereby treating periodontal diseases. CLINICAL SIGNIFICANCE: Ozone therapy is proving to be a new useful treatment modality which offers great benefits to the patients. The strong antimicrobial power of ozone, along with its ability to stimulate the circulatory system and modulate the immune response, makes it a remedial agent of choice in the treatment of various infectious oral diseases. The study was conducted to justify the routine use of ozone as a treatment modality in effective management of periodontal diseases.