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Background and Objective: Photodynamic therapy (PDT) and antiresorptive drugs, such as alendronate (ALN), have been shown to reduce alveolar bone loss. The aim of this study was to evaluate the possible synergic effects of combining PDT and ALN on bone loss in periodontitis in rats. Material and Methods: Periodontitis was induced by ligature in 60 Wistar rats randomized into the following groups: control (Group 1); PDT (Group 2); ALN 0.01 mg/kg (Group 3); ALN 0.25 mg/kg (Group 4); PDT + ALN 0.01 mg/kg (Group 5); and PDT + ALN 0.25 mg/kg (Group 6). The rats were killed on day 12 and the mandibles were processed for macroscopic morphometric analysis, micro‐computed tomography to analyze bone mineral density (BMD) and histological analysis. Gingival samples were collected to evaluate myeloperoxidase (MPO) and malonaldehyde (MDA) levels. Results: Bone loss and inflammatory activity in histological studies, from the greatest to least was: control > ALN 0.01 mg/kg > PDT > ALN 0.25 mg/kg > PDT + ALN 0.01 mg/kg > PDT + ALN 0.25 mg/kg, while the order from least to greatest BMD was: control < ALN 0.01 mg/kg < PDT < ALN 0.25 mg/kg < PDT + ALN 0.01 mg/kg < PDT + ALN 0.25 mg/kg. The order of MPO and MDA activity from greatest to least was: control > ALN 0.01 mg/kg > PDT > ALN 0.25 mg/kg > PDT + ALN 0.01 mg/kg > PDT + ALN 0.25 mg/kg. The positive results obtained in the group treated with PDT + ALN 0.25 mg/kg showed statistically significant differences (P ≤ .05) compared with the other 5 groups for BMD, MPO and MDA. Conclusion: Combined approach therapy of PDT + ALN 0.25 mg/kg demonstrated a protective effect on alveolar bone loss. [ABSTRACT FROM AUTHOR]

Purpose: The aim was to investigate the accuracy of quantitative computed tomography bone mineral density (BMD) measurements in mandibles, comparing measured BMD with calibrated BMD., Materials and Methods: Seventy mandibles from adult cadavers were used. Twenty tomographic cuts were made in each mandible. In each tomographic cut, a region of interest was located, and the bone density was measured in Hounsfield unit (HU). A polymethyl methacrylate phantom containing four inserts of different predetermined densities (hydroxyapatite 100, 200, 500, and 700 mg/cm(3) ) was used to calculate calibrated bone density. Correlation between measured and calibrated bone densities was calculated., Results: Mean total correlation between measured and calibrated BMD in the 20 sagittal tomography cuts showed almost perfect positive correlation (r = 0.998, p < .001). However, when average BMD measurements in HU were compared, the measured total BMD (in the 20 sagittal tomography cuts studied) was 54.99 ± 421.59, whereas the total calibrated BMD was 49.28 ± 364.95, with statistically significant difference (p = .001)., Conclusions: There are discrepancies between measured and calibrated BMD; in this sense, a calibrated bone phantom with a predetermined mineral density should be used to determine the exact BMD before dental implants surgery., (© 2013 Wiley Periodicals, Inc.)

Background/aim: The aim of this in vitro study was to investigate the impact fracture resistance of anterior teeth that had been fractured and restored with modified partial-coverage ceramics using the edge-up technique., Material and Methods: A total of 178 extracted human mandibular central and lateral incisors were included in this study. The incisors were randomly divided into two groups. Group 1 (n = 89) teeth were cleaved and restored with modified partial-coverage ceramics using the edge-up technique; Group 2 (n = 89) consisted of intact teeth that served as control. Impact strength was tested in a modified impact testing machine (pendulum type), and the severity of crown fracture after fracture resistance test was registered., Results: Impact strength was insignificantly lower in restored teeth (median 5.39 and range 0.81-14.12 kJ m(-2) ) than in intact teeth (median 5.45 and range 0.31-16.47 kJ m(-2) ), although no statistically significant differences were observed. Regarding the severity of crown fracture, restored teeth showed a lower rate of severe fractures (20.22%) compared to intact teeth (25.84%), but no statistically significant differences were observed., Conclusions: Restoration of cleaved mandibular incisors with modified partial-coverage ceramics using the edge-up technique shows fracture resistance and severity of crown fracture following traumatism similar to intact teeth. In this way, this technique can be used successfully for the treatment of fractured anterior teeth., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)