The effect of dental pulp stem cells and L-PRF when placed into the extraction sockets of impacted mandibular third molars on the periodontal status of adjacent second molars: a split-mouth, randomized, controlled clinical trial.

PURPOSE: To compare the clinical and radiographic effectiveness of dental pulp stem cells (DPSCs) seeded onto L-PRF and L-PRF alone in the extraction socket of mandibular third molars. METHODS: This study analyzed 13 patients who required surgical removal of impacted bilateral mandibular third molars. The main outcome measures were the probing pocket depth (PPD) and clinical attachment levels (CAL) that were recorded for the adjacent second molars (LM2) at the baseline and 6 months after surgery. The secondary outcomes were radiographic vertical bone loss (VD) and relative bone density (rBD) distal to the LM2. RESULTS: Twenty-six LM2s were evaluated. After 6 months, the L-PRF and L-PRF + DPSC groups showed a significant reduction in PPD (1.65 ± 1.01 mm and 1.54 ± 0.78 mm) and CAL (2.23 ± 1.45 mm and 2.12 ± 0.74 mm), respectively. There was no difference between the groups for any periodontal parameters. No significant differences were found between the groups regarding the VD or rBD at the sixth month. CONCLUSIONS: This study found that there was a significant improvement regarding the PPD, CAL, and VD measurements with the application of L-PRF, both alone and with the addition of DPSC, at the extraction socket. DPSC did not significantly contribute to the results compared to L-PRF therapy alone. TRIAL REGISTRATION: This study was registered on 23 December 2020 on ClinicalTrials.gov under the number NCT04641533.

Effects of Renal Transplantation and Hemodialysis on Patient's General Health Perception and Oral Health-Related Quality of Life: A Single-Center Cross-Sectional Study.

BACKGROUND: Patients with end-stage renal disease have a lower quality of life compared to the general population. Oral health-related quality of life (OHRQoL) is of particular interest as good oral health could influence general health. This study aimed to compare dental and periodontal health status, OHRQoL, and general health perception of renal transplant (TX) and hemodialysis patients (HD) with that of healthy controls. METHODS: The study included 64 TX, 63 HD, and 61 healthy patients. TX patients were also grouped according to the time elapsed after transplantation and currently use of immunosuppressive agents. The numbers of decayed, missing, and filled teeth were recorded as DMFT, and periodontal health status was evaluated. Patients' general health perceptions and OHRQoL were assessed using Short Form-36, Oral Health Impact Profile-14, and OHRQoL-United Kingdom questionnaires. RESULTS: The HD groups presented significantly higher DMFT scores and periodontal scores than TX and control groups. OHRQoL-United Kingdom total scores of TX and HD groups were lower than controls (P < .05). Oral Health Impact Profile-14 total scores revealed that HD groups' OHRQoL was significantly lower than TX and control groups (P < .05). Perceptions of general health of TX patients were higher than in the HD group. CONCLUSIONS: Renal transplantation has shown to increase quality of life and OHRQoL compared to hemodialysis therapy. Neither the immunosuppressive agent nor the time elapsed after transplantation were observed to be significant factors affecting OHRQoL.

Positive effect of platelet rich fibrin on osseointegration

BACKGROUND: Leukocyte-platelet rich fibrin (L-PRF) is a second generation platelet concentrate clinically used to accelerate tissue healing and bone regeneration. Achieving reduced implant osseointegration time could provide immediate or early loading of implants. The aim of this study was to evaluate the L-PRF-induced osseointegration and bone-implant contact (BIC) in an experimental animal model. MATERIAL AND METHODS: Twelve 4-month-old New Zealand white rabbits were used. Following general anesthesia, 3-5 mL of blood was obtained from the central artery in rabbit ear and L-PRF was prepared. Two implant cavities (5 mm long and 3 mm in diameter) were created in each tibia with a total of four cavities in each animal. Two of these cavities were selected and covered with PRF (test group). The remaining L-PRF was used to soak the implants placed into the L-PRF covered sockets. Other cavities were left as controls. In total, 48 implants were placed. Animals were sacrificed after two, three, or four weeks. Histological samples were obtained and periimplant tissues were histomorphometrically evaluated for bone-to-implant contact and new bone formation. RESULTS: Histomorphometric analyses of the defects revealed that the L-PRF was detectable up to the second week. Application of L-PRF increased the rate and amount of new bone formation in the experimental group compared to the control group. Bone-to-implant contact was enhanced when the surface was prewetted with LPRF (p < 0.01). CONCLUSIONS: The results of this study demonstrated that L-PRF application may increases amount and rate of new bone formation during the early healing period and provides a faster osseointegration around implants

Treatment of Peri-implant Bone Defects with Platelet-Rich Fibrin.

The objective of this study was to investigate and compare the clinical effectiveness of the application of platelet-rich fibrin (PRF) and conventional flap surgery for the treatment of peri-implant bone loss. Nineteen patients (8 women, 11 men) with peri-implant bone loss were randomly allocated to two groups, with the PRF group comprising patients who received fibrin scaffold and the control group made up of those who received only the access flap. At 3 and 6 months after surgery, respectively, the PRF group demonstrated higher mean probing depth reductions (2.41 ± 1.06 and 2.82 ± 1.03 mm versus 1.65 ± 1.02 and 2.05 ± 0.77 mm) and more gains in clinical attachment level (2.89 ± 1.01 and 3.31 ± 1.08 mm versus 1.43 ± 1.08 and 1.84 ± 0.81 mm) compared with the control group. In addition, the increase in the amount of keratinized mucosa from baseline to 6 months postoperatively was statistically significant for the PRF group (P < .001). Hence, the data from the current study led to the conclusion that PRF application in periimplant bone loss provided better clinical results than conventional flap surgery.

Influence of recasting different types of dental alloys on gingival fibroblast cytotoxicity.

STATEMENT OF PROBLEM: Surplus alloy from the initial casting is commonly reused with the addition of new alloy. This recasting procedure could affect the cytotoxicity of dental alloys. PURPOSE: The purpose of this in vitro study was to evaluate the effect of repeated casting of high-noble and base metal alloys on gingival fibroblast cytotoxicity. MATERIAL AND METHODS: Disk-shaped specimens (5 × 2 mm, n=60) of a high-noble (Au-Pt) and 2 base metal (Ni-Cr and Cr-Co, n=20) alloys were prepared with 100% new alloy and 50%, 65%, and 100% once recast alloy. The elemental composition of specimens was analyzed with X-ray energy-dispersive spectroscopy. Five specimens from each group were conditioned in saline with 3% fetal bovine serum albumin. The conditioning media were analyzed for elemental release with atomic absorption spectroscopy. Cytotoxic effects were assessed on human gingival fibroblast with a 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyl tetrazolium bromide (MTT) colorimetric assay. The data were analyzed with 1-way and 2-way ANOVA and Tukey's HSD multiple comparison test (α-=.05). RESULTS: Elemental compositions of Co-Cr and Au-Pt alloys were significantly different among casting protocols. Elemental release of Co-Cr and Ni-Cr alloys was significantly different between new and recast specimens (P<.001). Nickel release increased with recast alloy addition. The 2-way ANOVA showed a significant effect of the casting procedure (P<.001) alloy group (P<.001) and their interaction for cytotoxicity (P<.001). The Ni-Cr alloy groups with 65% and 100% recast alloy had lower cellular activity than all other specimens (P<.001). CONCLUSIONS: The results of this study indicated that alloys containing nickel have increased cytotoxic effects and that composition of the alloys affected the cytotoxicity. Furthermore, recasting nickel-containing alloys with 65% surplus metal addition significantly increased the cytotoxic activity.

Repositioning a prosthetically unfavorable implant by vertical distraction osteogenesis.

Prosthetically unfavorable implant positions challenge patients and restorative dentists. Surgical correction of malpositioned implants may be an alternative technique for esthetically and biomechanically acceptable prosthetic restorations. This case report describes an alveolar distraction technique used to coronally reposition a dental implant and the 3-year results in the maintenance phase. To our knowledge, long-term follow-up of this method of correction is unprecedented. The present case report describes the repositioning of an apically positioned and fully osseointegrated implant at the right maxillary canine region using an alveolar distraction technique. Distraction was performed at 1 mm per day and ended when the implant moved 6 mm coronally. After a consolidation phase of 8 weeks, an implant-supported fixed prosthetic restoration was performed. Healing was uneventful after removal of the distractor. During the 3-year follow-up, the implant was fully functional with minimal probing depths, negligible signs of inflammation, and no further bone loss. This intervention illustrates the promise of an alveolar distraction osteogenesis procedure for vertical repositioning of apically positioned implants. This technique also provided soft and hard tissue remodeling to obtain an esthetic and stable restoration.

Comparison of different methods to detect Helicobacter pylori in the dental plaque of dyspeptic patients.

The aim of this study was to compare different methods of detection of Helicobacter pylori (H. pylori) in the dental plaque of dyspeptic patients. After recording the clinical indices, culture and polymerase chain reaction (PCR) methods were performed on plaque samples, while rapid urease test in addition to these tests was carried on gastric samples from 67 dyspeptic patients who attended for an upper gastrointestinal endoscopy. Forty-seven of 67 patients were H. pylori-positive in gastric biopsy material whereas the microbial dental plaque from 19 patients demonstrated H. pylori positivity detected by PCR. Among the patients, 25.4% harbored H. pylori both in the stomach and in microbial dental plaque. No significant correlations were found among the presence of H. pylori in the stomach, in plaque, and clinical variables (P > 0.05). Although oral hygiene was observed optimal and the mean of pocket depth was not found to be higher, the prevalence of H. pylori was observed to be higher in dental plaque. According to our results, PCR technique gave the highest detection rate both in gastric biopsy and in dental plaque compared to the other methods used.

Apoptosis in cyclosporin A-induced gingival overgrowth: a histological study.

BACKGROUND: Cyclosporin A (CsA) is known to induce gingival overgrowth. Apoptosis plays a critical role in the regulation of inflammation and the host immune response. The aim of this study was to investigate apoptosis in CsA-induced gingival enlargement using electron microscopy examination of keratinocytes. METHODS: Gingiva specimens were collected from 12 CsA-treated renal transplant patients with gingival overgrowth and eight healthy controls with gingivitis. Clinical findings (probing depth, gingival index, and plaque index) were compared in the two groups. Histological and ultrastructural features of the specimens were also compared, and extent of keratinocyte apoptosis was scored on a three-tier scale: 0 = no apoptotic cells; 1 = one or two apoptotic cells; 2 = more than two cells. RESULTS: There were no significant differences between groups with respect to gingiva-related clinical findings or extent of keratinocyte apoptosis. CONCLUSIONS: The results indicate that the extent of keratinocyte apoptosis in the gingiva of kidney recipients with CsA-induced gingival overgrowth is similar to that observed in inflamed gingiva of healthy individuals. Further studies on apoptosis of different cell types in the presence of CsA should clarify this agent's role in the pathogenesis of drug-induced gingival enlargement.

Effect of cyclosporin A on apoptosis and expression of p53 and bcl-2 proteins in the gingiva of renal transplant patients.

BACKGROUND: Gingival overgrowth (GO) is a common side effect of cyclosporin A (CsA) therapy, but the exact mechanism for this is unknown. Apoptosis plays an important role in the maintenance of tissue homeostasis and mediators of this process may be involved in the pathogenesis of drug-induced GO. This study compared p53 expression, bcl-2 expression, and apoptosis in gingival samples from CsA-treated renal transplant recipients to findings in controls with gingivitis. METHODS: Twenty-two kidney recipients with CsA-induced GO and 15 systemically healthy subjects with gingivitis were included in the study. The 15 systemically and periodontally healthy volunteer control group were immunohistochemically analyzed for grades of p53 and bcl-2 expression, and were processed using terminal TdT-mediated dUTP-biotin nick-end labeling (TUNEL) technique to identify and grade levels of apoptosis. RESULTS: There were no differences between the CsA group and the control group with respect to grades of p53 and bcl-2 expression (P >0.05 for both). However, the CsA group showed a lower apoptosis grade than the control group (P <0.05). None of the clinical parameters was significantly correlated with any of the immunohistochemical findings for p53 or bcl-2 (P >0.05 for all). Similarly, grade of apoptosis was not correlated with any of the clinical parameters (P >0.05). There was a significant positive correlation between serum CsA level and level of bcl-2 expression, but serum CsA was not significantly correlated with level of apoptosis or level of p53 expression. CONCLUSION: The results indicate that the pathogenesis of CsA-induced GO might involve inhibition of apoptosis, and overexpression of bcl-2 in the setting of high serum CsA.

Immunohistochemical analysis of lymphocyte subpopulations in cyclosporin A-induced gingival overgrowth.

BACKGROUND: Cyclosporin A (CsA) is an immunosuppressive agent that is known to induce gingival overgrowth (GO). Pharmacological, genetic, immunologic, and inflammatory factors seem to be involved in the complex pathogenesis of drug-induced GO. Lymphocyte subpopulations in human gingival connective tissue have been implicated in the pathogenesis of inflammatory periodontal diseases. One purpose of this study was to quantify CD4, CD8-, CD57-, and epithelial membrane antigen (EMA)-positive cells in the gingiva of renal transplant recipients treated with CsA, and compare them to findings in healthy controls. A second aim was to correlate cell numbers with clinical findings. METHODS: The study included 19 kidney recipients who were taking CsA and had significant GO (CsAGO+), 13 recipients who were taking CsA but showed no GO (CsAGO-), and 14 systemically healthy individuals with gingivitis (C). Sections from gingival biopsies were incubated with monoclonal antibodies for CD4, CD8, EMA, and CD57, and then analyzed using the avidin-biotin complex method. In each specimen, the mononuclear cell types were quantified and their distribution was evaluated in 3 separate tissue zones: S = subepithelial connective tissue beneath the sulcular epithelium; O = subepithelial connective tissue beneath the oral epithelium; and M = middle connective tissue. RESULTS: There were no significant differences among the groups with respect to the numbers of CD4+ and CD8+ cells in each of the 3 zones (P >0.05). In zone S, the CsAGO+ group had significantly more EMA-positive cells than either the C or CsAGO- groups (P <0.05). There were significant differences among the groups regarding numbers of CD57+ (natural killer) cells in zone M, with the lowest cell numbers in the CsAGO+ patients (P<0.05). CONCLUSIONS: The results showed that low numbers of natural killer cells are important in the expression of plaque-induced inflammatory changes in CsA-associated GO. It appears that these cells may influence the drug's ability to induce proliferative activity.