Using Platelet-Rich Fibrin in Combination With Allograft Bone Particles Can Induce Bone Formation in Maxillary Sinus Augmentation.

BACKGROUND: Sinus pneumatization secondary to posterior maxillary tooth extraction can hinder proper implant installation. Maxillary sinus floor augmentation is a surgical procedure that has been proposed to overcome this issue. PURPOSE: The aim of this study was to evaluate and compare the histomorphometric outcomes of sinus floor elevation using allograft bone particles with or without platelet-rich fibrin (PRF). STUDY DESIGN, SETTING, SAMPLE: This randomized clinical trial included patients scheduled for maxillary sinus floor elevation in the Implant Department of Mashhad Dental School. Healthy adults with an edentulous maxilla and residual alveolar bone height of 3 mm or less were eligible to participate and were randomly allocated to intervention (A) or control (B) groups. Bone biopsies were obtained 6 months postoperatively. PREDICTOR VARIABLE: The predictor variable was using a PRF membrane for maxillary sinus augmentation. In group A, sinus floor elevation was performed using PRF combined with bone allografts, while in group B only allograft particles were used. MAIN OUTCOME VARIABLES: The primary outcome variables were the recorded postoperative histologic parameters, as in the area of newly formed bone, new bone marrow, and residual graft particles (µm2). The secondary outcome variables were the radiographically measured postoperative bone height and width at the graft site. COVARIATES: Age and sex. ANALYSES: Independent sample t-test was employed to compare the postoperative histomorphometric parameters between groups A and B. P value ≤ .05 was considered statistically significant. RESULTS: A total of 20 patients (10 per group) completed the study. The mean rate of new bone formation was 43.25 ± 5.22% in group A and 38.25 ± 7.01% in group B. This difference was statistically insignificant (P = .087). The mean amount of newly formed bone marrow was significantly more in group A compared to group B (6.81 ± 2.19% vs 10.23 ± 4.49%; P = .044). The average amount of remaining particles was also significantly less in group A patients (9.35 ± 3.43% vs 13.18 ± 3.67%; P = .027). CONCLUSION AND RELEVANCE: Incorporating PRF as an adjunctive grafting material results in fewer residual particles of allograft and in more bone marrow formation and may serve as a treatment option for developing the atrophic posterior maxilla.

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.

Evaluation of the Topical Effect of Probiotic Mouthwash in the Treatment of Patients with Peri-Implant Mucositis.

Peri-implant mucositis is a reversible inflammatory process of the soft tissue surrounding a dental implant. If left untreated, peri-implant mucositis can evolve into peri-implantitis, which leads to the loss of the supporting bone around the implant. The treatment of peri-implantitis is of special importance, since peri-implantitis can be very expensive and troublesome for both the patient and the dentist and a lack of complete resolution can lead to a low probability of implant success. This study aims to evaluate the effects of probiotic tablets on the condition of patients with peri-implant mucositis after scaling. In this double-blind randomized intervention trial, packages containing 14 probiotic capsules or a single-dose placebo were provided to 25 volunteer patients after scaling among those called to a private clinic in Mashhad. During the research process, we used the probing depth (PD) index and the bleeding on probing (BOP) index to diagnose peri-implant mucositis before and after the 28-day period. According to the study findings, on the day of scaling and 4 weeks after scaling and mouthwash use, there was a statistically significant difference in BOP index values between the probiotic group and the placebo group (P < 0.001). There was no difference in PD index values between these two groups. In conclusion, probiotic treatment can be used in interventions, prevention, and dentists' recommendations to alleviate or eradicate peri-implant mucositis.

A novel mutation in the cathepsin C (CTSC) gene in Iranian family with Papillon-Lefevre syndrome.

OBJECTIVES: In this study, we analyzed the whole exomes of CTSC gene in a family with history of PLS. MATERIALS AND METHODS: Genomic DNA was extracted from peripheral blood and genotype analysis was performed. The mutated protein sequence was used to find the best possible tertiary structure for homology modeling. The homology modeling of the novel mutation was then performed using the online Swiss-Prot server. The results were also analyzed for to verify its validity. RESULTS: The analysis of CTSC gene elucidated a novel insertion GAC. The novel mutation was proved by analyzing 50 healthy control volunteers. Modeling of the novel found mutation in CTSC gene revealed structural defects that may have caused the functional abnormalities. CONCLUSIONS: The structural analysis of the mutated protein model identifies changes in the stereo-chemical and the energy level of the mutated protein. Since this protein play a role in the activation of granule serine proteases from cytotoxic T lymphocytes, natural killer cells, mast cells, such structural defects may lead to its malfunction causing dysfunctioning of immune defense mechanisms.

The evaluation of implant stability measured by resonance frequency analysis in different bone types.

OBJECTIVES: Bone density seems to be an important factor affecting implant stability. The relationship between bone density and primary and secondary stability remains under debate. The aim of this study was to compare primary and secondary stability measured by resonance frequency analysis (RFA) between different bone types and to compare implant stability at different time points during 3 months of follow-up. MATERIALS AND METHODS: Our study included 65 implants (BioHorizons Implant Systems) with 3.8 or 4.6 mm diameter and 9 or 10.5 mm length in 59 patients. Bone quality was assessed by Lekholm-Zarb classification. After implant insertion, stability was measured by an Osstell device using RFA at three follow-up visits (immediately, 1 month, and 3 months after implant insertion). ANOVA test was used to compare primary and secondary stability between different bone types and between the three time points for each density type. RESULTS: There were 9 patients in type I, 18 patients in type II, 20 patients in type III, and 12 patients in type IV. Three implants failed, 1 in type I and 2 in type IV. Stability values decreased in the first month but increased during the following two months in all bone types. Statistical analysis showed no significant difference between RFA values of different bone types at each follow-up or between stability values of each bone type at different time points. CONCLUSION: According to our results, implant stability was not affected by bone density. It is difficult to reach a certain conclusion about the effect of bone density on implant stability as stability is affected by numerous factors.

Evaluation of the effects of subgingival injection of Simvastatin on space re-opening after orthodontic space closure in adults.

Background. This clinical trial evaluated the effect of Simvastatin on space re-opening after orthodontic space closure and its effect on the gingival index (GI) and clinical attachment loss (CAL). Methods. 16 females, 25-40 years old, with spaces between anterior mandibular teeth due to chronic periodontitis were participated in this study. The patients were randomly divided into control and experimental groups. In the experimental group, 1.2% Simvastatin gel and in the control group, 0.9% sodium chloride as a placebo was injected into the pocket depth of the six anterior teeth. The amount of space reopening, GI and CAL were measured. Results. No serious complications were observed during interventions and follow-up periods. Space re-opening was significantly reduced in patients receiving Simvastatin (P < 0.001). Moreover, GI reduction was significantly greater in Sim-vastatin group compared to the control group (P < 0.001). However, CAL did not demonstrate a significant difference between the groups. Conclusion. Simvastatin may decrease space re-opening after orthodontic space closure in human anterior teeth.

Comparison of Two Regenerative Surgical Treatments for Peri-Implantitis Defect using Natix Alone or in Combination with Bio-Oss and Collagen Membrane.

The aim of this clinical trial was to evaluate 6-month clinical and radiographic outcomes after surgical regenerative therapy of peri-implantitis lesions using either porous titanium granules (Natix, Tigran Technologies, Malmo, Sweden) alone or bovine bone mineral (Bio-Oss, Giestlich, Wolhusen, Switzerland) with a collagen membrane (B&B Dental Implant Company, San Pietro, Italy). Twenty-four patients having at least one implant with a peri-implantitis lesion were involved in this study. Patients were assigned randomly into two groups and treated with two different regenerative approaches. The first group (Group 1) received Natix alone and the second group (Group 2) received Bio-Oss plus collagen membrane after debridement of the defect. Probing depth, clinical attachment level, and radiographic measurements were recorded at baseline and after 6 months of healing. One patient with one implant from Group 1 and another patient with 2 implants from the Group 2 discontinued the study. Mean pocket depth change was 1.1 ± 1.4 mm in Group 1 and 1.1 ± 2.1 mm in Group 2. Bone level changes were 0.85 ± 1.06 and 1.4 ± 1.04 mm in the two groups, respectively, over the 6-month follow-up period. Neither clinical nor radiographical differences between the two groups were statistically significant. We conclude that both application of porous titanium granules and Bio-Oss plus collagen membrane resulted in clinical improvement of peri-implantitis lesions over a period of 6 months.

Evaluation of Alveolar Crest Changes following Buccal Bone Overbuilding in Immediate Implantation.

The aim of the present study was to evaluate alveolar crest changes when using demineralized freeze-dried bone allograft (DFDBA) and resorbable membrane between flap and buccal bone in addition to filling the gap, as compared to merely filling the gap, when performing immediate implantation. In 18 patients with 24 single-root teeth, implants were placed immediately after extraction. In the test group (nine patients with 12 teeth), DFDBA and barrier membrane were placed between buccal crest and flap after implant placement. In the control group (nine patients with 12 teeth), implants were placed without buccal grafting. In addition, in both groups, if the gap width between implant and buccal crest was ≥2 mm, the gap was filled with DFDBA at the time of extraction. The height of buccal crest soft tissue and the buccolingual width of bone at 3 and 5 mm, apical to the line connecting the two cementoenamel junctions (CEJs) of adjacent teeth (CEJ line), were measured at baseline and after 4 mo. In the test group, the mean height of the buccal crest increased by 1.04 ± 0.68 mm, but in the control group, height decreased by 0.83 mm (p < 0.001). In the test group, the mean height of soft tissue increased by 0.29 mm, but in the control group, height decreased by 0.79 ± 0.72 mm (p = 0.006). The mean reduction of buccolingual width of bone in 3 and 5 mm apical to the crest in the test group was lower than that of the control group, but not significantly (p = 0.231 and 0.212, respectively). The findings of this study show that using DFDBA and membrane between buccal crest and flap in immediate implantation could increase buccal crest and soft tissue height in the midfacial region but may not significantly prevent buccolingual width reduction of bone at 3 and 5 mm from the CEJ line.

Protein modeling of cathepsin C mutations found in Papillon-Lefèvre syndrome.

BACKGROUND: Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive disorder characterized by hyperkeratosis involving the palms, soles, elbows, and knees followed by periodontitis, destruction of alveolar bone, and loss of primary and permanent teeth. Mutations of the lysosomal protease cathepsin C gene (CTSC) have been shown to be the genetic cause of PLS. This study analyzed CTSC mutations in five Iranian families with PLS and modeled the protein for mutations found in two of them. METHODS: DNA analysis was performed by direct automated sequencing of genomic DNA amplified from exonic regions and associated splice intron site junctions of CTSC. RFLP analyses were performed to investigate the presence of previously unidentified mutation(s) in control groups. Protein homology modeling of the deduced novel mutations (P35 delL and R272P) was performed using the online Swiss-Prot server for automated modeling and analyzed and tested with special bioinformatics tools to better understand the structural effects caused by mutations in cathepsin C protein (CTSC). RESULTS: Six Iranian patients with PLS experienced premature tooth loss and palm plantar hyperkeratosis. Sequence analysis of CTSC revealed a novel mutation (P35delL) in exon 1 of Patient 1, and four previously reported mutations; R210X in Patient 2, R272P in Patient 3, Q312R in two siblings of family 4 (Patients 4 and 5), and CS043636 in Patient 6. RFLP analyses revealed different restriction fragment patterns between 50 healthy controls and patients for the P35delL mutation. Modeling of the mutations found in CTSC, P35delL in Patient 1 and R272P in Patient 3 revealed structural effects, which caused the functional abnormalities of the mutated proteins. CONCLUSIONS: The presence of this mutation in these patients provides evidence for founder CTSC mutations in PLS. This newly identified P35delL mutation leads to the loss of a leucine residue in the protein. The result of this study indicates that the phenotypes observed in these two patients are likely due to CTSC mutations. Also, structural analyses of the altered proteins identified changes in energy and stereochemistry that likely alter protein function.

In vitro antimicrobial comparison of chlorhexidine, persica mouthwash and miswak extract.

AIM: Herbal mouthwashes, such as persica (Salvadora persica, mint and yarrow extracts) and miswak extract have been shown to decrease gingival inflammation and plaque accumulation. The aim of this study was to compare the antimicrobial activities of persica and miswak extract with the conventional mouthwash chlorhexidine against Streptococcus salivarius, Streptococcus sanguis, Lactobacillus vulgaris and Candida albicans. MATERIALS AND METHODS: In this in vitro study, blood-agar culture (Merk, Germany) was used to grow the streptococcus strains, saburd-dextrose culture (Merk, Germany) was used to grow C. albicans and MRS-agar was used to grow L. vulgaris. Various concentrations of these substances (0.1, 0.05 and 0.025% of miswak extract, 0.1, 0.05, 0.025 and 0.0125% of persica, 0.2, 0.1, 0.05 and 0.025% of chlorhexidine) were added to paper disks, separately, inserted into culture plates and transferred into the incubator. The inhibition zone around each disk was measured after 24 hours and the data was analyzed by the Kruskal-Wallis test. RESULTS: Chlorhexidine possessed antibacterial activity at all concentrations tested. It was more effective than persica and miswak at all concentrations on S. salivarius (p = 0.022 for 0.1%, 0.009 for 0.05 and 0.025%). It had greater effect than the other two tested material on S.sanguis only at concentration 0.01%. Chlorhexidine was the most effective against S.salivarius; persica was the most effective against Lactobacillus (p = 0.005) and the least effective against S. salivarius; and miswak extract was the most effective against S. salivarius and S. sanguis at concentrations 0.1 and 0.05% (p = 0.005) and ineffective against L. vulgaris. None of these mouthwashes were effective against C. albicans. CONCLUSION: This study revealed that chlorhexidine remains the gold standard as an antimicrobial agent, although herbal based mouthwashes do have marginal antimicrobial activities. It is necessary to conduct more clinical and microbiological studies focusing on periodontal pathogens and anaerobic microorganisms. CLINICAL SIGNIFICANCE: Mechanical plaque control is the main way for periodontal disease prevention and mouthrinses are used to improve its efficacy. Based on the results of this study, chlorhexidine has the most antibacterial effect and although persica mouthwash and miswak are routinely used in some Asian countries their antibacterial efficacies are suspected.

The effect of periodontal treatment on IL-6 production of peripheral blood monocytes in aggressive periodontitis and chronic periodontitis patients.

BACKGROUND: Several cytokines, including IL-6 have been implicated in the pathogenesis of periodontal disease. It is established that monocytes from periodontitis subjects show an increased production of IL-6 as compared to healthy subjects. However, little is known about the effect of periodontal treatment on IL-6 production by monocytes in subsets of periodontitis patients. OBJECTIVE: The aim of the present study was to evaluate the effect of surgical periodontal treatment on IL-6 production of peripheral blood monocytes (PBM) in aggressive periodontitis patients (AP) and chronic periodontitis patients (CP) before and after stimulation by E.coli LPS. METHODS: Fifteen AP patients, 15 CP patients and 15 periodontally healthy subjects (PH) took part in the study. PBM IL-6 pro-duction was measured, using ELISA, before and after stimulation of cultured PBM cells by 0.1 microg/ml LPS of E.coli. Following full-mouth non-surgical and surgical periodontal treatment of the AP and CP groups, the same measurements were repeated for these two groups. RESULTS: LPS-stimulated IL-6 production was significantly greater than non-stimulated IL-6 for all 3 groups. Before periodontal treatment, LPS-stimulated IL-6 pro-duction of the AP group was significantly greater than the other 2 groups. Periodontal treatment did not result in a significant decrease in unstimulated or LPS-stimulated IL-6 production by PBM cells in AP and CP patients. No correlation was detected between IL-6 levels and baseline clinical parameters or changes in clinical parameters. CONCLUSION: PBM cells in AP patients might be hyper-responsive in terms of IL-6 production. This hyper-responsiveness does not seem to return to that of healthy subjects even after a successful periodontal treatment. Moreover, the regulation of host inflammatory mechanisms upon LPS challenge might be different between AP and CP patients.