Alveolar ridge dimensional changes following ridge preservation procedure using SocketKAP(™) : exploratory study of serial cone-beam computed tomography and histologic analysis in canine model.

INTRODUCTION: The aim of this pilot study was to examine the kinetics of alterations in alveolar ridge width and height following tooth extraction with and without ridge preservation, using anorganic bovine bone mineral (ABBM) and a novel device (SocketKAP(™) ) designed for obturation of socket orifice. MATERIALS AND METHODS: Maxillary left and right PM1 and mandibular right PM2 and PM4 were extracted on six beagle dogs and treated as follows: Group A: negative control; Group B: SocketKAP(™) alone; Group C: ABBM + SocketKAP(™) . Serial cone-beam computed tomography (CBCT) was taken at 0-, 1-, 2-, 4-, 8- and 12-week intervals to calculate the rate of alveolar bone loss, followed by histologic and histomorphometric analyses at 12 weeks. Across group outcomes were compared. RESULTS: Without additional intervention, the crestal-most 3 mm of alveolar bone width lost approximately 0.21-0.28 mm per week. The rate of alveolar buccal bone height loss was 0.19 mm per week. Comparatively, in group C, the alveolar bone was relatively stable, with loss of only 0.003-0.13 mm of width and 0.12 mm of height per week. These differences were statistically significant. The alveolar bone in sites treated by SocketKAP(™) alone was significantly different from control only at select time points and locations of the ridge, presumably due to small sample size. CONCLUSION: Without additional intervention, tooth extraction was accompanied by rapid loss of alveolar ridge width and height. Applications of SocketKAP(™) and ABBM were effective in reducing alveolar crestal width and height loss following tooth extraction.

Growth and osteogenic differentiation of alveolar human bone marrow-derived mesenchymal stem cells on chitosan/hydroxyapatite composite fabric.

Scaffolds can be used for tissue engineering because they can serve as templates for cell adhesion and proliferation for tissue repair. In this study, chitosan/hydroxyapatite (CS/HAp) composites were prepared by coprecipitation synthesis. Then, CS and CS/HAp fabrics were prepared by wet spinning. CS fibers with a diameter of 15 ± 1.3 µm and CS/HAp fibers with a diameter of 22 ± 1.2 µm were successfully produced; incorporation of HAp into the CS/HAp fibers was confirmed by X-ray diffraction analysis. Biological in vitro evaluations showed that human mesenchymal stem cells (hMSCs) cultured on CS/HAp fabric showed increased proliferation compared to those cultured on pure CS fabric, which was observed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, DNA content assay, and [(3) H] thymidine incorporation assay. Neither the CS nor CS/HAp scaffold exhibited any cytotoxicity to hMSCs, as shown by viability staining and cytotoxicity fluorescence image assays. After 10 days of culturing, the attachment of cells onto the scaffold was observed by scanning electron microscopy. Furthermore, under osteogenic differentiation conditions, alkaline phosphatase (ALP) activity and calcium accumulation was higher in cells cultured on the CS/HAp scaffold than in cells cultured on the CS scaffold. The mRNA expression of osteoblast markers, including ALP, osteocalcin, Co1Ia1, and runt-related transcription factor 2, was higher in cells cultured on CS/HAp than in cells cultured on the CS fabric. The results of this study indicate that the CS/HAp composite fabric may serve as a good scaffold for bone tissue engineering applications.

Association of gingival biotype with the results of scaling and root planing.

PURPOSE: The concept of gingival biotype has been used as a predictor of periodontal therapy outcomes since the 1980s. In the present study, prospective and controlled experiments were performed to compare periodontal pocket depth (PPD) reduction and gingival shrinkage (GSH) after scaling and root planing (SRP) according to gingival biotype. METHODS: Twenty-five patients diagnosed with chronic periodontitis participated in the present study. The PPD and GSH of the labial side of the maxillary anterior teeth (from the right canine to the left canine) were evaluated at baseline and 3 months after SRP. Changes in the PPD following SRP were classified into 4 groups according to the gingival thickness and initial PPD. Two more groups representing normal gingival crevices were added in evaluation of the GSH. The results were statistically analyzed using the independent t-test. RESULTS: In the end, 16 patients participated in the present study. With regard to PPD reduction, there were no significant differences according to gingival biotype (P>0.05). Likewise, sites with a PPD of over 3 mm failed to show any significant differences in the GSH (P>0.05). However, among the sites with a PPD of under 3 mm, those with the thin gingival biotype showed more GSH (P<0.05). CONCLUSIONS: PPD changes after SRP were not affected by gingival biotype with either shallow or deep periodontal pockets. GSH also showed equal outcomes in all the groups without normal gingival crevices. The results of SRP seem not to differ according to gingival biotype.