Titanium scaffold osteogenesis in healthy and osteoporotic rats is improved by the use of low-level laser therapy (GaAlAs).

The present study aimed to assess the effects of low-level laser therapy (GaAlAs) on the bone repair process within titanium scaffolds in the femurs of healthy and osteoporotic rats. Fifty-six rats were divided into four groups: group Sh: SHAM animals that received scaffolds; group LSh: SHAM animals that received scaffolds and were subjected to laser therapy; group OV: ovarietomized (OVX) animals that received scaffolds; and group LOV: OVX animals that received scaffolds and were subjected to laser therapy. Thirty days following ovariectomy or sham surgery, scaffolds were implanted in the left femurs of all animals in the study. Immediately after opening the surgical site, the inner part of the surgical cavity was stimulated with low-level laser (GaAlAs). In addition to this procedure, the laser group was also subjected to sessions of low-level laser therapy (LLLT) at 48-h intervals, with the first session performed immediately after surgery. The rats were sacrificed at 2 and 6 weeks, time in which femur fragments were submitted for histological and histomorphometric examination, and skin tissue above the scaffold was submitted to histological analysis. At the end of the study, greater bone formation was observed in the animals submitted to LLLT. At 2 and 6 weeks, statistically significant differences were observed between LSh and Sh groups (p = 0.009 and 0.0001) and LOV and OV (p = 0.0001 and 0.0001), respectively. No statistical difference was observed when assessing the estrogen variable. On the basis of our methodology and results, we conclude that LLLT improves and accelerates bone repair within titanium scaffolds in both ovariectomized and healthy rats, when compared to animals not subjected to radiation.

Microdeformation of Infrastructure for Implant-Supported fixed Dental Prosthesis by Strain-Gauge Method: Influence of Technique and Material Impression

To verify the structural microdeformationby strain gages, around implants that have metal infrastructure, obtained by different materials and techniques impressions.Material and Methods:Three internal hexagon implants in polyurethane block (master model) with abutments were taken the impression with differents materials and techniques impression (n=4): addition silicon and transfer for open tray technique (Group I), condensation silicon and transfer for closed tray technique (Group II); and polyether and transfer for open tray techniques (GroupIII). Impressions were poured with type IV stone. Metallic infrastructure were made and installed in the master model by an aid of a manual ratchet wrench. A torque of 20N was used to install the metallic infrastructure. Microdeformation analysis was performed around the implants by strain gauge method. Two gauges were inserted into the polyurethane base, and three measurements were taken for each infrastructure. Data were analyzed using descriptive statistics and inference. Kruskal-Wallis test was used toverify association between materials and impression techniques and deformation around the implants, at 5% confidence.Results:Microdeformationsaround the implants showed no statistically significant difference (p = 0.123) between the experimental groups, Group I (215.8 με), Group II (194.9 με) and Group III (297.4 με). Conclusion:The use of different materials and techniques impression to madeof infrastructures for fixed implant-supported dental prosthesis did not present difference in microdeformation values around implants...