Significance of keratinized mucosa around dental implants: a prospective comparative study.

OBJECTIVE: The aim of this investigation was to evaluate the significance of keratinized mucosa (KM) around dental implants both clinically and biochemically for 12 months. MATERIAL AND METHODS: Fifteen edentulous patients treated with implant-retained overdentures in edentulous mandible (four implants per patient). Based on the presence of keratinized mucosa on the buccal surfaces, implants were divided into two groups: Implants having minimal 2 mm of KM on their buccal surfaces and implants having no KM on their buccal surfaces. Thirty-six implants were included in the evaluations; 19 implants in 15 patients had minimal 2 mm of KM on their buccal surfaces and 17 implants in 15 patients had no KM on their buccal surfaces. Clinical measurements of Plaque Index, Gingival Index, probing depths, and Bleeding on Probing were performed and peri-implant crevicular fluid (PICF) were collected immediately before loading (baseline) and at 6th, 12th months after loading. Interleukin-1 beta (IL-1 ß) and tumor necrosis factor-alpha (TNF-α) have been assessed in the crevicular fluid. Results were analyzed by repeated-measures of variance (ANOVA) and Wilcoxon signed rank tests. RESULTS: After 12 months of evaluation the results of ANOVA showed that implants with KM had lower levels of TNF-α total amounts than implants without KM (P < 0.05). Additionally, TNF-α total amounts were significantly higher at 12(th)  month compared to baseline for implants without KM (P < 0.05). Plaque index and Gingival index values were also found significantly higher for implants without KM (P < 0.05). For IL-1 ß and PICF volume levels the differences between the implant groups were non significant, whereas the differences between the periods were significant. (P < 0.05) Additionally, both of the groups had higher levels of PII and BoP scores when compared to baseline (P < 0.05). CONCLUSIONS: The results of this study showed that an adequate band of keratinized mucosa was related with less plaque accumulation and mucosal inflammation as well as pro-inflammatuar mediators, suggesting that it may be critical especially for plaque control and plaque associated mucosal lesions around dental implants.

Periodontal nitric oxide pathway alteration due to precompetition anxiety in handball players.

BACKGROUND: Psychologic and physical stress is known to be related with periodontal disorders. The objective of this study is to investigate salivary and gingival crevicular fluid (GCF) nitric oxide (NO) metabolism and its association with the periodontal reaction to precompetition anxiety in competitive athletes. METHODS: A total of 18 elite male handball players participated in this study. The anxiety level of participants was determined by using a competitive state anxiety inventory-2 (CSAI-2). Periodontal clinical measurements, saliva, and GCF samples were obtained before the application of the CSAI-2 during the half-season break and just before the league championship match. NO-level, arginase, and NO synthase (NOS) activities were analyzed in saliva samples; NO and basic fibroblast growth factor (FGF-b) levels were analyzed in GCF samples. RESULTS: The CSAI-2 was significantly different between the two evaluation time points. GCF NO and FGF-b levels increased before the championship match, whereas saliva levels did not change. The plaque index and gingival index (GI) increased at the evaluation just before the championship match. The difference in the GI was statistically significant. CONCLUSION: The competitive stress of athletes may lead to a gingival/periodontal disturbance accompanied by an altered NO metabolism in saliva and GCF.

Bacterial adhesion and colonization differences between zirconium oxide and titanium alloys: an in vivo human study.

PURPOSE: The purpose of this study was to compare zirconium oxide and titanium alloys with respect to their tendency to adhesion and colonization of two periodontal pathogens on both hard surfaces and on soft tissues in vivo. MATERIALS AND METHODS: The present study was designed as a prospective stratified randomized controlled clinical trial. Patients were scheduled to receive two implants with different types of abutments in the posterior mandible. Three months after implant placement, titanium and zirconium abutments were connected. Five weeks after abutment connections, the abutments were removed, probing depth measurements were recorded, and gingival biopsy samples were obtained. Abutments and biopsy specimens were analyzed by reverse-transcriptase polymerase chain reaction to compare the DNA copy numbers of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and total bacteria. The surface free energy of the abutments was calculated by sesile water drop before replacement. RESULTS: No statistically significant differences were found between probing depths or DNA copy numbers of A actinomycetemcomitans, P gingivalis, and total bacteria both for both titanium alloys and zirconium oxide surfaces and the biops specimens obtained from their buccal gingival. With respect to the surface free energy of zirconium and titanium abutments, zirconium abutments showed lower surface free energy than titanium abutments. CONCLUSION: The results of this study showed that zirconium oxide surfaces have comparable properties to titanium alloy surfaces in their tendency to adhesion and colonization of two periodontal pathogens on both hard surfaces and in soft tissues.

Clinical and radiographic evaluations of chitosan gel in periodontal intraosseous defects: a pilot study.

Periodontitis is a chronic infection in the supportive tissue of the teeth which eventually leads to tooth loss. Various grafting materials and barrier membranes have been used to repair periodontal intraosseous lesions. Chitosan is a derivative of chitin, a natural biopolymer, which is biologically safe, biodegradable, and nontoxic and has been applied in a variety of forms in dentistry. It also exerts bioactive properties such as wound healing, antimicrobial, tissue regeneration, and hemostatic activities. The aim of this study was to evaluate effects of chitosan on periodontal regeneration. Twenty chronic periodontitis patients were recruited. Following initial therapy, the patients were divided into four groups: group A, receiving chitosan gel (1% w/v); group B, receiving chitosan gel + demineralize bone matrix; group C: receiving chitosan gel + collagenous membrane; and group D, receiving flap only (control group). Clinical and radiographic measurements were recorded at baseline, day 90 (3rd month), and day 180 (6th month) after surgery. For clinical data, no significant differences were obtained among the treatment groups. However, radiographic data revealed that except control group, all the other groups showed statistically significant bone fills when compared with baseline indicating that chitosan gel alone or its combination with demineralize bone matrix/collagenous membrane is promising for periodontal regeneration.