Marginal bone loss around crestal or subcrestal dental implants: prospective clinical study.

Objectives: The stability of crestal bone has been reported as a major factor in the success of dental implants. Implants can be placed in an equicrestal (crestal) or subcrestal position. The aim of this study was to evaluate the effect of implant depth placement on marginal bone loss. Materials and Methods: The study was created in a split-mouth design. Immediately after implant surgery, digital parallel radiographs were prepared and levels of bone were measured where marginal bone loss and bone level changes occurred. These measurements were repeated at 3-month and 6-month follow-up periods. Results: In this interventional study, 49 implants were evaluated in 18 patients. Primary bone height was not significant between the intervention and control groups in both mesial and distal aspects at 3 months and 6 months from the baseline. The mean marginal bone loss on the mesial side was 1.03 mm in the subcrestal group and 0.83 mm in the crestal group. In addition, mean marginal bone loss on the distal side was 0.88 mm and 0.81 mm in the subcrestal and crestal groups, respectively. Marginal bone loss was not significantly different between sexes, the maxilla or mandible, and in the anterior or posterior regions as well as between different lengths and diameters of implants. Conclusion: Based on the results of this study, there was no significant difference in terms of marginal bone loss between crestal and subcrestal implants.

Age-Dependent Three-Dimensional Evaluation of Circummaxillary Sutures Maturation in Normal Population Using Cone-Beam Computed Tomography: Early Childhood Through Adolescence.

INTRODUCTION: Initiation time of dentofacial orthopedics is as important as the choice of treatment protocol. Morphology and degree of fusion of circummaxillary sutures differ in various populations; hence, the aim of this study was to evaluate the exact age of ossification of the most important maxillary suture using cone-beam computed tomography to find the appropriate age to start orthopedic treatment. METHODS AND MATERIALS: This cross-sectional retrospective study was performed on 517 cone-beam computed tomography images of patients aged 6 to 18 years old. Patients with obvious pathology or fractures were excluded from the study. Two independent observers scored the radiographs. The ossification stage of the zygomatico-maxillary suture (ZMS) was classified into 5 stages and each suture was classified according to age and sex of the patients. Kendall Taub, Kruskal-Wallis, Mann-Whitney U test, and Bayesian analysis were used for statistical analysis. Statistical significance was set at P value < 0.05. RESULTS: In this study, 517 samples consisting of 260 females (50.3%) and 257 males (49.7%) with a mean age of 12.03 ± 3.74 years old were examined. A significant difference did not exist between the 2 sexes regarding the stages of ZMS ossification except for in stage E. The ZMS transitional stage from B to C was found to occur at the age of 11.8 in boys and 12.6 in girls. CONCLUSIONS: According to the transitional age of ZMS maturation from stage B to C, it seems that orthopedic treatments of the maxilla are not much effective after the age of 12. Therefore, the authors should start orthopedic treatment of the maxilla before the age of 12 in both sexes.

In-vitro evaluation of the effect of canal curvature on adaptation of gutta-percha in canals obturated with HEROfill system by CBCT.

A hermetic seal of the root canal space following canal preparation is important in endodontics. This study evaluated the effect of canal curve on adaptation of gutta-percha to dentinal walls of canals obturated using the Herofill system. For this in vitro study, 80 mesial roots of mature human first molars with length of 16 mm, curve between 5° and 45°, and no caries or resorption of the root surface were selected. A cone beam computed tomography system was used to evaluate the presence or absence of a gap in the samples. Photographs were taken in three sections: 2 mm above the curve, at the curve and 2 mm below the curve. The gap area was identified using Photoshop and AutoCAD software. Kruskal Wallis and Mann-Whitney tests were used to analyze the data mounted in a castcurve. There were significant differences between the two lateral condensation groups with various curves; roots with more curve had more gaps. When the Herofill and lateral condensation groups were compared without considering the sections and curve, there was a significant difference between these groups and the Herofill group had less gaps. The Herofill system is an alternative to the lateral condensation technique in severely curved canals.