The objective of this study was to compare the effects of preparing for implant site osteotomy with conventional drilling or piezosurgery on the stability of oral implants after a 5 month follow-up period. Thirty patients participated in this randomized clinical trial and received two implants in posterior mandible in bone of the same quality. All surgical procedures were performed by the same surgeon. Implant stability amounts were measured by resonance frequency analysis using the Osstell Mentor device and are reported in the format of implant stability quotient (ISQ) values at baseline and 90 and 150 days after surgery. All implants were well osseointegrated. Differences in ISQ levels were statistically significant in the piezosurgery group at all time intervals, whereas those in the conventional drill group were not significant as analyzed by analysis of variance. The significance of differences between the two groups in each time interval was assessed with Student's t test. In the second interval (90 days), there were statistically significant differences in ISQ levels between the two groups at the buccal, lingual side of implants and mean of two measurements, but at baseline and 150 days, there were no significant differences between these techniques. The early increase of ISQ values in piezoelectric sites shows that piezosurgery is a less traumatic bone osteotomy method with a shorter inflammatory phase and little resorption compared with sites prepared by conventional drilling. ISQ values of up to 60-65 at the time of insertion of the implant predict a good prognosis for immediate implant loading. In this study, the ISQ values were almost always higher than this, offering the safe condition for immediate or early loading protocols after the piezoelectric method of implant site osteotomy. These results may increase predictability of immediate-loading procedure in oral implantology.

PurposeThis study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from conebeam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard.Materials and MethodsA radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values (MGVs) of each cylinder were calculated in each imaging protocol.ResultsIn both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes (P<.05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV.ConclusionThe size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results.

Context: This article reviews the available evidence about the barrier membranes utilized in Guided Tissue Regeneration process to prevent the migration of unfavorable cells to the wound area. Evidence Acquisition: Available evidence about membranes properties and their different uses were reviewed, and the results of clinical and animal studies and systematic reviews were gathered. Results: A large number of existing membranes with different features and compositions may lead to different study results; none of the available membranes can result in %100 predictable outcomes. Conclusions: Effectiveness of membranes in treating intrabony defects is very controversial; however, treating furcation defects using membranes was reported to be successful in a large number of studies.

Because primary stability has a critical role in implant osseointegration, greater insertion torque is more desirable. However, excessive pressure on the peri-implant bone may lead to bone resorption. This study evaluates the effect of insertion torque on crestal bone level. Periapical radiographs of 136 bone-level implants were assessed in this retrospective cohort study. Sixty-four implants were inserted with high insertion torques (45-70 N/cm) and 72 implants were placed with a torque in the range of 20 to 30 N/cm. The distance between implant shoulder and proximal bone crest was measured on radiographs taken immediately after the insertion and compared to those calculated after uncovering surgeries (inserting the healing abutment). The mean bone resorption around implants placed with high and lower insertion torques was 0.33 and 0.4, respectively; thus, the difference between the two groups was insignificant (p = 0.88). High insertion torques (up to 70 N/cm) did not significantly increase bone resorption around implants.

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