Vojislav Lekovic

Platelet-rich fibrin and bovine porous bone mineral vs. platelet-rich fibrin in the treatment of intrabony periodontal defects.

BACKGROUND AND OBJECTIVE Bovine porous bone mineral (BPBM) is a xenograft that has been successfully utilized in periodontal regeneration. Platelet-rich fibrin (PRF) is a leukocyte and platelet preparation that concentrates various polypeptide growth factors and therefore has the potential to be used as regenerative treatment for periodontal defects. The purpose of this study was to examine the suitability of autologous PRF as regenerative treatment for periodontal intrabony defects in humans and to examine the ability of BPBM to augment the regenerative effects exerted by PRF. MATERIAL AND METHODS Using a split-mouth design, 17 paired intrabony defects were randomly treated either with PRF or with PRF-BPBM combination. Re-entry surgeries were performed at 6 mo. Primary study outcomes were changes in pocket depth, attachment level and defect fill. RESULTS Preoperative pocket depths, attachment levels and transoperative bone measurements were similar for the PRF and PRF-BPBM groups. Postsurgical measurements revealed a significantly greater reduction in pocket depth in the PRF-BPBM group (4.47±0.78 mm on buccal and 4.29±0.82 mm on lingual sites) when compared with the PRF group (3.35±0.68 mm on buccal and 3.24±0.73 mm on lingual sites). The PRF-BPBM group presented with significantly greater attachment gain (3.82±0.78 mm on buccal and 3.71±0.75 mm on lingual sites) than the PRF group (2.24±0.73 mm on buccal and 2.12±0.68 mm on lingual sites). Defect fill was also greater in the PRF-BPBM group (4.06±0.87 mm on buccal and 3.94±0.73 mm on lingual sites) than in the PRF group (2.21±0.68 mm on buccal and 2.06±0.64 mm on lingual sites). CONCLUSION The results of this study indicate that PRF can improve clinical parameters associated with human intrabony periodontal defects, and BPBM has the ability to augment the effects of PRF in reducing pocket depth, improving clinical attachment levels and promoting defect fill.

A Surgical Reentry Study on the Influence of Platelet-Rich Plasma in Enhancing the Regenerative Effects of Bovine Porous Bone Mineral and Guided Tissue Regeneration in the Treatment of Intrabony Defects in Humans

BACKGROUND The purpose of this study was to evaluate the additional benefits provided by the incorporation of platelet-rich plasma (PRP) into a regenerative protocol consisting of bovine porous bone mineral (BPBM) and guided tissue regeneration (GTR) in the treatment of intrabony defects in humans. METHODS Twenty-three paired intrabony defects were surgically treated using a split-mouth design. Defects were treated with BPBM/GTR/PRP (experimental group) or with BPBM/GTR (control group). The clinical parameters evaluated included changes in probing depth, clinical attachment level, and defect fill as revealed by reentry surgeries at 6 months. RESULTS Preoperative probing depths, attachment levels, and transoperative bone measurements were similar for the two groups. Post-surgical measurements taken at 6 months revealed that both treatment modalities resulted in a significant decrease in probing depth, gain in clinical attachment, and bone fill of the defects compared to baseline. Postoperative differences observed between the two groups were 0.72 +/- 0.36 mm at buccal sites and 0.90 +/- 0.32 mm at lingual sites for probing depth, 0.82 +/- 0.41 mm at buccal sites and 0.78 +/- 0.38 at lingual sites for gain in clinical attachment, and 0.85 +/- 0.36 mm at buccal sites and 0.94 +/- 0.42 mm at lingual sites for defect fill, all favoring the experimental sites. However, none of the differences were statistically significant. CONCLUSION Within the limitations related to using a small sample size, PRP did not significantly augment the effects of BPBM and GTR in promoting the clinical resolution of intrabony defects.

Bone loss biomarkers associated with peri‐implantitis. A cross‐sectional study

AIM To investigate the levels of biomarkers associated with osteoclastogenesis in patients suffering peri-implantitis and to compare them with levels in healthy peri-implant sites and severe chronic periodontitis. MATERIAL AND METHODS Peri-implant/gingival crevicular fluid samples and clinical parameters including: bleeding on probing, modified Plaque Index (PlI), pocket depth and clinical attachment level were collected from 70 patients (23 with peri-implantitis, 25 with healthy peri-implant tissues and 22 with severe chronic periodontitis). The concentrations of sRANKL, RANK and OPG were evaluated using enzyme-linked immunosorbent assays; they were compared between the groups and correlated with the clinical findings. RESULTS sRANKL (P = 0.01), RANK (P = 0.01) and OPG (P = 0.03) concentrations were significantly higher in peri-implantitis sites when compared to those in healthy implant sites, although differences in the sRANKL/OPG ratio were not statistically significant. In these sites all three markers were significantly correlated with the clinical parameters, with exception of OPG/PI correlation that remained insignificant (P = 0.121). When comparing peri-implantitis and periodontitis findings, RANK was significantly higher in peri-implantitis sites whereas, sRANKL (P = 0.03) and sRANKL/OPG ratio (P = 0.004) were significantly higher in periodontitis sites. Among periodontitis and healthy implant sites the same differences have been observed for both sRANKL (P = 0.000) and sRANKL/OPG ratio (P = 0.000), furthermore RANK was higher in periodontitis sites as well (P = 0.010). CONCLUSION The findings of this preliminary study on a relatively small sample size suggest that the PICF levels of biomarkers sRANKL, RANK, and OPG are associated with peri-implant tissue destruction and the pattern of these biomarkers differed when compared to periodontitis.

Gingivomorphometry - esthetic evaluation of the crown-mucogingival complex: a new method for collection and measurement of standardized and reproducible data in oral photography

OBJECTIVES A new method is introduced for the esthetic evaluation of the periimplant mucogingival complex through collection of standardized oral photographs and computer-assisted measurement of reproducible data. Using this method, different soft tissue and crown parameters in the dentogingival complex can be measured and the esthetic outcome monitored. MATERIAL AND METHODS A photographic device for standardized oral photography and a standard protocol for the esthetic evaluation of the crown-mucogingival complex is presented, comprising six soft tissue parameters: (1) mesial and (2) distal papilla areas, (3) mesial and (4) distal papilla heights, (5) soft tissue-crown perimeter, and (6) gingival recession. In order to demonstrate the reproducibility of standardized oral photographs and the accuracy of the measurement of the six parameters, the data obtained in each of two such standardized clinical photographs, taken at 10-14 days intervals, of the anterior maxillary region from 10 patients with no apparent dental disease were compared. For the statistical analysis of the reproducibility of these dependent data the 95% confidence interval and the coefficients of variation were calculated from measurement means and ranges of each of the above parameters, pooled from all 10 patients. RESULTS Statistical analysis revealed high reproducibility with no significant differences between the range of mean values of all six parameter measurements on the first and second standardized oral photograph of the same patient, respectively. CONCLUSION Gingivomorphometry on standardized oral photographs can be considered to be an accurate and reproducible method for the evaluation and measurement of different dentogingival and periimplant parameters.

Prevalence of human cytomegalovirus and Epstein-Barr virus in subgingival plaque at peri-implantitis, mucositis and healthy sites. A pilot study

This study evaluated the prevalence of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in peri-implantitis and mucositis sites and the correlation between herpesvirus and clinical parameters. Fifty-six dental implants (mean time of loading, 4.27±1.6 years) were evaluated (20 peri-implantitis, 18 mucositis, 18 healthy peri-implant sites.) The clinical parameters assessed were: visible plaque index (PI), bleeding on probing (BOP), suppuration (SUP), probing depth (PD). A polymerase chain reaction assay identified HCMV and EBV in subgingival plaque samples. The percent of sites with plaque and BOP was significantly higher around mucositis and peri-implantitis compared with healthy implants (p<0.05). The mean PD around the implants was significantly higher in peri-implantitis, followed by mucositis and healthy implants (p<0.05). HCMV was detected in 13 (65%) and EBV in 9 (45%) of the 20 peri-implantitis sites. HCMV was found in 1 of the 18 (6%) healthy periodontal sites and EBV in 2 (11%). A statistically significant correlation was found between presence of HCMV and EBV subgingivally and clinical parameters of peri-implantitis and healthy sites. These results confirm the high prevalence of HCMV and EBV in subgingival plaque of peri-implantitis sites and suggest the viruses have a possible active pathogenic role in peri-implantitis.

Correlation between different genotypes of human cytomegalovirus and Epstein-Barr virus and peri-implant tissue status

BACKGROUND The purpose of this study was to estimate the prevalence of different genotypes of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in peri-implantitis and mucositis sites, and to evaluate the correlation between herpesvirus presence and clinical parameters. METHODS A total of 80 dental implants (mean time of loading, 4.16 ± 1.8 years) were evaluated during the course of the study (30 peri-implantitis, 25 mucositis and 25 healthy peri-implant sites). The following clinical parameters were assessed: visible plaque index, bleeding on probing, suppuration and probing depth. A polymerase chain reaction (PCR) assay was used to identify the presence of different HCMV and EBV genotypes in peri-implant tissue plaque samples. RESULTS HCMV-2 was detected in 53.3% and EBV-1 in 46.6% of the 30 peri-implantitis sites evaluated. By contrast, HCMV-2 was not detected in healthy periodontal sites and EBV-1 was detected in one healthy site. A statistically significant correlation was found between the presence of HCMV-2 and EBV-1 genotypes and clinical parameters of peri-implantitis. CONCLUSIONS The results from the present study confirmed the high prevalence of HCMV-2 and EBV-1 in the peri-implant tissue plaque of peri-implantitis sites and suggests a possible active pathogenic role of the viruses in peri-implantitis.

Soft tissue development around abutments with a circular macro-groove in healed sites of partially edentulous posterior maxillae and mandibles: a clinical pilot study.

OBJECTIVES The aim of this study was to evaluate soft tissue development at concave circular macro-grooved titanium abutments in healed sites. MATERIAL AND METHODS In a split-mouth pilot study 10 patients received two implants each at healed posterior sites in contralateral maxillary or mandibular jaw quadrants. Either circular macro-grooved concave study abutments or conventional convex control abutments were immediately provisionalized and received permanent crowns 3 months postimplantation. Marginal bone level, papilla index, modified plaque and bleeding index were recorded. The esthetic outcome was evaluated with standardized perpendicular pictures according to the Pink Esthetic Score (PES). Statistical analysis included the description of all variables by mean value, standard deviation and range. PES values were compared using the Wilcoxon signed rank test for paired data. RESULTS Cumulative survival rate for all 20 implants was 100%. At the 1-year follow-up, there was no statistical significant difference of marginal bone levels between sites restored with the study (-0.11 ± 0.77 mm) vs. the control (-0.34 ± 0.53 mm) abutments (P>0.05). Esthetic evaluation (PES) revealed statistically significant differences in scores between the study group [study abutment group] (7.2 ± 2.82, 8 ± 1.89) and the control group [control abutment group] (9.5 ± 1.58, 10.5 ± 1.72) at the time of prosthetic delivery and the 1-year follow-up. Whereas PES scores for mesial papilla at control sites at the 1-year follow-up demonstrated statistically significant higher values, both soft tissue level and soft tissue contour at control sites revealed statistically significantly higher PES values (P<0.05) at time of prosthetic delivery and at 1-year follow-up when compared with study sites. CONCLUSIONS Concave macro-grooved abutments in healed posterior maxillary and mandibular sites did not exhibit a superior soft tissue development compared with standard convex abutments.

Clinical application of autologous fibroblast cell culture in gingival recession treatment

BACKGROUND AND OBJECTIVE Gingival recession is defined as soft and hard tissue displacement resulting in root surface exposure. The optimal outcome of gingival recession treatment is complete, predictable and long-lasting root coverage with a significant level of tissue regeneration. Tissue engineering, which applies active regeneration principles, presents the contemporary treatment approach in the restitution and regeneration of lost tissues. The objective of the present study was to evaluate and compare the clinical results of application of an autologous fibroblast cell culture (AFCC) on a collagen matrix and a connective tissue graft (CTG) placed under a coronally advanced flap (CAF), in the treatment of single and multiple gingival recessions. MATERIAL AND METHODS Eighteen patients from the Department of Periodontology, School of Dentistry, University of Belgrade, were randomly enrolled in this study. Inclusion criteria were the bilateral presence of Miller Class I or II single or multiple maxillary gingival recessions. A split-mouth design was used in the study. The experimental group was treated with AFCC on a collagen scaffold, which was placed under a CAF. The control group received a combination of CTG and CAF. Clinical parameters such as gingival recession coverage, keratinized tissue width, clinical attachment level and gingival index were recorded at baseline and at 12 mo postoperatively. The oral hygiene level was assessed by plaque index evaluation. Postoperative healing was evaluated through the healing index, recorded 1, 2 and 3 wk postoperatively. The final esthetic outcome was assessed using the mean root coverage esthetic score (RES). RESULTS Statistically significant improvement of all parameters assessed was found compared with baseline. A statistically significant difference between groups was observed only in keratinized tissue width. Greater keratinized tissue width is still obtained with the use of CTG. Regarding the tissue-healing results, no statistically significant difference was achieved. The RES results were similar for both groups. CONCLUSIONS Within the limitations of the present study, both procedures proved to be efficient in gingival recession treatment. AFCC, as a novel tissue-engineering concept and living cell-based therapy, proved to be a reliable and successful treatment concept.

Effects of the platelet rich plasma on apexogenesis in young monkeys: Radiological and hystologycal evaluation

Platelet-reach plasma (PRP) is an attractive tool in regenerative medicine due to its ability to stimulate proliferation and differentiation of stem cells. Since dental pulp derived stem cells are recognized as central in apexogenesis, the aim of the study was to evaluate radiologically and histologically effects of PRP on apexogenesis in teeth with immature roots. The study included eight monkeys (Cercopithecus Aethiops) divided in two equal groups for evaluation 3 and 12 months after treatment. All participants obtained the same treatment including pulpotomy and after-treatment with: hydroxiapatite (HA)-incisor and HA+canine PRP. Radiological evaluation was performed using the long cone paralleling technique for recording of defined parameters and histological evaluation was performed using tissue removed en block for the observation of parameters related to apexogenesis. The results obtained radiologically and histologically have shown increase in bridge formation in HA+PRP (75%) group after 3 months comparing to HA group (50%). Contrary to that, after 12 months there were no significant differences between groups. The root delay was not registered in the HA+PRP group contrary to HA group where it was registered in 25% after 12 months. Results of the study suggest that PRP is a powerful tool for intensive and rapid apexogenesis since it offers clear and comprehensive results (mostly in the first three months) which are early radiologically visible without any failure in the proposed requests.

Relationship between serum tumor necrosis factor receptor-2 concentration and periodontal destruction in patients with type 2 diabetes: Cross-sectional study

Introduction The role of tumor necrosis factor-α (TNFα) is well documented in pathogenesis of chronic periodontitis (CP) and type 2 diabetes (T2D). Considering short half-life of TNFα, tumor necrosis factor receptor-2 (TNFR2) is used as prosperous surrogate marker of TNFα activity. Objective The aim was to detect TNFR2 serum concentration and correlate it with periodontal destruction in patients with diagnosed T2D and nondiabetics. Methods The study included 85 patients divided into three groups: T2D + CP (group T2D, n = 34); nondiabetics + CP (Group PD, n = 27); and healthy controls (group HC, n = 24). T2D was diagnosed according to WHO criteria (2013) and periodontitis was diagnosed using International Workshop for a Classification of Periodontal Diseases and Conditions criteria (1999). TNFR2 level was measured by enzyme-linked immunosorbent assay (ELISA). Results There was no difference in TNFR2 level among the groups (Kruskal–Wallis, p = 0.482). Significant correlation (Pearson’s correlation coefficient) was observed between clinical attachment loss (CAL) and TNFR2 concentration in PD group (rp = -0.460, p = 0.016). In T2D group, correlations were observed between TNFR2 concentration and CAL (rp = 0.363, p = 0.005) and periodontal inflamed surface area (PISA) (rp = 0.345, p = 0.046) and periodontal epithelial surface area (PESA) (rp = 0.578, p = 0.000). Conclusion Higher concentration of TNFR2 was associated with higher CAL, PESA, and PISA scores in T2D group. Contrary to that, nondiabetics with higher values of CAL exhibited lower concentration of TNFR2, presenting potential protective effect on periodontal destruction. These results imply that diabetes may alter TNFR2 secretion originated from periodontium.