No abstract

Osteotome technique yielded higher primary stability than conventional drilling technique. However, this technique was not superior to conventional technique after 3 months.

Impression techniques should precisely represent the 3-dimensional status of implants to allow for the fabrication of passively fitting prostheses and subsequently the elimination of strain on supporting implant components and surrounding bone. The aim of this study was to compare the accuracy of an abutment level impression method with that of an implant level (direct and indirect) impression method using polyether impression material to obtain precise definitive casts and prostheses. A reference acrylic resin dentoform with 2 internal connection implants (Implantium) was made. A total of 21 medium-consistency polyether impressions of the dentoform, including 7 direct implant level, 7 indirect implant level, and 7 abutment level (after 2 straight abutments were secured), were made. Impressions were poured with American Dental Association (ADA) type IV stone, and the positional accuracy of the implant replica heads and abutment analogs in each dimension of x-, y-, and z-axes, as well as angular displacement (Δθ), was evaluated using a coordinate measuring machine. Noble alloy 3-unit castings were fabricated and seated on the abutments in 3 groups; marginal discrepancies were measured at 4 points between prostheses and abutments. Data were analyzed using Mann-Whitney U test, 1-way analysis of variance (ANOVA), and Kruskal-Wallis tests. In comparisons of different impression techniques, only significant statistical Δθ differences were noted between the abutment level method and other techniques (P < .001). Results of this study reveal that although the implant level impression method could better transfer the angular position of the implants (Δθ), the impression method could not affect Δy, Δx, and Δz coordinates of the implants or marginal discrepancy of the 3-unit fixed partial dentures (FPD).

Background Short implants have been proposed as an alternative for the rehabilitation of atrophic edentulous areas. Purpose To evaluate the efficacy of 4‐mm implants vs longer implants in the atrophic posterior mandibles. Materials and Methods Eleven patients with bilateral atrophic mandibles were rehabilitated with two to four 4‐mm implants and 10 or 8‐mm long implants in augmented bone using Guided Bone Regeneration procedure. One side of the mandibles was randomly allocated to vertical augmentation with mixed autogenous bone and allograft. Implants were placed in both sides of the mandible after 6 months, and loaded after another 2 months. Subsequently, implant and prosthesis failures, marginal bone levels changes, and any complication were evaluated after 1‐year follow‐up. Results In this study, one patient dropped out and no failures occurred. However, 4‐mm implants loss of 0.30 ± 0.34 mm peri‐implant marginal bone and long implants loss of 0.47 ± 0.54 mm marginal bone were observed after 1‐year of follow‐up. The difference between the two groups was not statistically significant (difference = −0.16 ± 0.68 mm; P = 0.46). Eight complications occurred in five augmented sites of the patients, and no complication was found to occur in the short implants sites. Conclusions One‐year after loading, 4‐mm implants had similar outcomes as long implants in augmented bone. Therefore, short implants might be a feasible treatment in atrophic mandibles.

Compared to NaOCl (5.25 %), nano-MgO (5 mg/L) exhibits statistically significant long-term efficiency in the elimination of E. faecalis in the root canal system. After further investigations, nano-MgO could be considered as a new root canal irrigant.