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 (Kruskal­Wallis, 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.

MMP-9 -1562 C>T (rs3918242) promoter polymorphism as a susceptibility factor for multiple gingival recessions.

The objective of this pilot study was to investigate the potential role of -1562 C>T single nucleotide polymorphism (SNP) in the promoter region of the matrix metalloproteinase-9 (MMP-9) gene as a risk modulator in the development of multiple gingival recessions (MGRs) in young adults in the Serbian population. The study sample comprised 161 systemically healthy people: 60 with MGRs and 101 controls with healthy periodontal tissues. Genotyping was done using polymerase chain reaction/restriction fragment length polymorphism approach on DNA obtained from buccal swabs. Clinical measurements included vertical recession depth (VRD), clinical attachment level (CAL), keratinized gingival width (KGW), visible plaque index (PI), and bleeding on probing (BOP). Heterozygotes (CT) were significantly more frequent in the MGRs group than in the control group (P = .005) and carriers of the T allele had an approximately threefold increase of MGRs risk. Patients with the CT genotype exhibited significantly higher values of VRD and CAL and significantly lower values of KGW than patients with the wildtype genotype. Associations among different genotypes and periodontal biotypes in the MGRs group remained insignificant because all participants exhibited thin biotype. The -1562 C>T SNP in the promoter region of MMP-9 appears to be a risk factor for MGR development and a potential predictor of more severe clinical phenotype.

Receptor activator of nuclear factor kappa B (RANK) as a determinant of peri-implantitis.

BACKGROUND/AIM: Peri-implantitis presents inflammatory process that affects soft and hard supporting tissues of osseointegrated implant based on inflammatory osteoclastogenesis. The aim of this study was to investigate whether receptor activator of nuclear factor kappa B (RANK) concentrations in peri-implant crevicular fluid could be associated with clinical parameters that reflect inflammatory nature of peri-implantitis. METHODS: The study included 67 patients, 22 with diagnosed peri-implantitis, 22 persons with healthy peri-implant tissues and 23 patients with periodontitis. Clinical parameters from each patient were recorded and samples of peri-implant/gingival crevicular fluid were collected for the enzyme-linked immunosorbent assay (ELISA) analysis. RESULTS: RANK concentration was significantly increased in samples from the patients with peri-implantitis when compared to healthy implants (p < 0.0001), where the average levels were 9 times higher. At the same time RANK concentration was significantly higher in peri-implantitis than in periodontitis sites (p < 0.0001). In implant patients pocket depths and bleeding on probing values were positively associated with high RANK concentrations (p < 0.0001). CONCLUSION: These results revealed association of increased RANK concentration in samples of peri-implant/gingival crevicular fluid with peri-implant inflammation and suggests that RANK could be a pathologic determinant of peri-implantitis, thereby a potential parameter in assessment of peri-implant tissue inflammation and a potential target in designing treatment strategies.

Impact of interleukin 1 gene polymorphism and smoking on long-term stability following gingival recession treatment.

Risk factors such as smoking, genetic factors, and tissue biotype play an important role in the etiology, predictability, and long-term stability of gingival recession treatment. This study was designed to evaluate the influence of interleukin 1 (IL-1) polymorphism and smoking on the stability of gingival recession treatment after 1 and 3 years. All patients (n = 55) were treated for type I and II recession defects using a connective tissue graft. Clinical evaluations were performed, which included assessment of vertical recession depth, gingival inflammation, and clinical attachment level. A fingerstick blood sample was collected using specially provided DNA filter paper and mailed for processing in a laboratory using polymerase chain reaction-based methodology. The results indicated that 19 subjects were genotype positive (34.5%). Treatment of the localized recessions was effective and provided a similar amount of coverage in genotype-positive and genotype-negative subjects within smoking and nonsmoking groups after 1 year. In a 3-year period, nonsmoking patients with positive IL-1 genotype lost approximately 20% of the root coverage gained at 1 year and were almost four times more inferior compared with genotype-negative patients. Patients who smoked and had a positive IL-1 genotype lost approximately 35% of the gained root coverage. IL-1 polymorphism and smoking habit did not affect gingival recession treatment at 1 year but had a great impact on long-term stability.

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.

[Immediate implant loading with fixed dental restorations--an animal model study].

BACKGROUND/AIM: Immediate loading is considered to be the most innovative technique in contemporary implant dentistry. Recent clinical and experimental findings have demonstrated that only implants with high primary stability can be subjected to immediate loading protocol with predictable results. It is generally accepted that the most important prerequsite for successful osseointegration is achievement and maintenance of implant stability. The aim of this in vivo study was to investigate the possibility for successful application of immediate loading protocol in implant systems with different surface properties. METHODS: In the experimental study 2 mongrel dogs were edentulated bilaterally in the mandibular and maxillary premolar areas. After 3 months implants were placed in a pattern 4 different commercially available implants per quadrant (n = 32): Mk III TiUnite (Nobel Biocare, Sweden), ITI TPS (Straumann, Switzerland), 31-Osseotite (Implant Innovation, USA) and XiVE Cell-Plus (Friadent, Germany). Implants were subjected to immediate loading with 4 unit gold cast bridges, 2 days post implantation. The assessment of implant stability and immediate loading possibilities were done by performing Resonance frequency analysis (RFA). RESULTS: After a 6-month loading period all bridges were in function and all implants occurred well osseointegrated. When summarizing the Implant Stability Quotient (ISQ) values, it was noted that resonance frequency was significantly higher for mandibular implants. The results of this experimental setting showed that all evaluated surfaces achieved good implant stability. Increase of ISQ values was found for all implants in the mandible and partially decrease of ISQ values for maxillary implants after 6 months of functional loading with 4 unit bridges. CONCLUSIONS: Investigated endooseal implants did not show different degree of osseointegration, because there was not statisticaly significant difference among observed parameters (ISQh i ISQp) between implant systems.

Use of platelet-rich fibrin membrane following treatment of gingival recession: a randomized clinical trial.

This 6-month randomized controlled clinical study primarily aimed to compare the results achieved by the use of a platelet-rich fibrin (PRF) membrane or connective tissue graft (CTG) in the treatment of gingival recession and to evaluate the clinical impact of PRF on early wound healing and subjective patient discomfort. Use of a PRF membrane in gingival recession treatment provided acceptable clinical results, followed by enhanced wound healing and decreased subjective patient discomfort compared to CTG-treated gingival recessions. No difference could be found between PRF and CTG procedures in gingival recession therapy, except for a greater gain in keratinized tissue width obtained in the CTG group and enhanced wound healing associated with the PRF group.

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.

[The use of platelet-rich fibrin membrane in gingival recession treatment].

INTRODUCTION: Fibrin, fibronectin, platelet derived growth factor, and transforming growth factors from platelet concetrate are crucial for tissue reparation and regeneration. OBJECTIVE: This study was designed to evaluate clinical effectiveness of activated platelet-rich fibrin (PRF) membrane in treatment of gingival recession. METHODS: 19 gingival recessions Miller class I or II were treated with a coronally advanced flap and the PRF membrane (PRF group). Following the elevation of the flap, bone and root surfaces were covered with the PRF membrane. After suturing, the PRF membrane was covered with a coronally advanced flap. In the same patients, 19 other gingival recessions were treated with CTG in combination with the coronally advanced flap (the CTG group). Clinical recordings were made of vertical recession depth (VRD), probing depth (PD), clinical attachment level (CAL) and keratinized tissue width (KTW) before and 12 months after mucogingival surgical treatment. Clinical evaluation of healing events was estimated with recordings of the healing index (HI). Recordings of HI were performed in the 1st, 2nd and 3rd week post-surgically. RESULTS: Mean root coverage was significant in both groups (the PRF group 79.94% and the CTG group 88.56% %; p < 0.01). The difference between the two tested groups was not statistically significant. Results of the keratinized tissue width showed significant increase (p < 0.05) 12 months after the surgery in both, the PRF and CTG groups. Results of KTW showed statistical significance of recorded differences obtained in the two evaluated groups (p < 0.05). There was no statistical significance in reduction of PD and CAL recorded in the PRF and CTG groups. The values of HI recorded in the 1st and 2nd week postoperatively were significantly enhanced in the PRF group (p < 0.05). CONCLUSION: Results of this study confirm both procedures as effective with equivalence of clinical results in solving gingival recession problems. The utilization of the PRF resulted in a decreased postoperative discomfort and advanced tissue healing.

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.

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.

Mechanical stability of immediately loaded implants with various surfaces and designs: a pilot study in dogs.

PURPOSE: Immediate loading is among the most innovative techniques in implant therapy today. This pilot study investigates the biomechanical outcome of various designs and surfaces that claim to shorten implant treatment. MATERIALS AND METHODS: In each quadrant of two mongrel dogs, four different implants were used for immediate loading. The following implants were placed 3 months after tooth extraction: screw with low thread profile and anodic oxidized surface (LPAOS), solid screw with wide thread profile and titanium plasma spray coating (WPTPS), screw with low profile and hybrid design of double-etched and machined surface (LPHES), and screw with two thread profiles and a sandblasted and acid-etched surface (DTSAE). The insertion torque of each implant was above 35 Ncm. Resonance frequency analysis was performed after implant placement and again after sacrifice. Additionally, the removal torque and the amount of embedded titanium particles in the peri-implant bone were measured. RESULTS: All 16 prostheses were functional after a 5-month loading period. The highest mean removal torque values were recorded with WPTPS implants (24.4 Ncm/mm), followed by DTSAE implants (22.3 Ncm/mm) and LPAOS implants (18.7 Ncm/mm); the lowest score was obtained by LPHES (12.0 Ncm/mm). The ISQ values increased between the time of surgery and recall for all systems on average, but a significant positive correlation was found for DTSAE only. Significantly higher amounts of titanium were found in the surrounding bone with WPTPS (0.76%) and LPAOS (0.41%) in comparison with DTSAE (0.10%) and LPHES (0.03%). CONCLUSION: Immediate loading is possible with various designs and surfaces if high primary stability can be achieved during implant placement.

[Identification of periodontopathogen microorganisms by PCR technique].

INTRODUCTION: Periodontitis is an inflammatory disease of the supporting tissues of teeth and is a major cause of tooth loss in adults. The onset and progression of periodontal disease is attributed to the presence of elevated levels of a consortium of pathogenic bacteria. Gram negative bacteria, mainly strict anaerobes, play the major role. OBJECTIVE: The present study aimed to assess the presence of the main types of microorganisms involved in the aetiopathogenesis of periodontal disease: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Eikenella corrodens, Treponema denticola, Tanerella forsythia and Prevotella intermedia in different samples collected from the oral cavity of 90 patients diagnosed with periodontitis. METHOD: Bacterial DNA detection was performed in diverse biological materials, namely in dental plaque, gingival tissue and saliva, by means of multiplex PCR, a technique that allows simultaneous identification of two different bacterial genomes. RESULTS: In the dental plaque of the periodontitis patients, Treponema denticola dominated. In the gingival tissue, Tannerella forsythia and Treponema denticola were the microbiota most frequently detected, whilst in saliva Treponema denticola and Eikenella corrodens were found with the highest percentage. CONCLUSION: The identification of microorganisms by multiplex PCR is specific and sensitive. Rapid and precise assessment of different types of periodontopathogens is extremely important for early detection of the infection and consequently for the prevention and treatment of periodontal disease. In everyday clinical practice, for routine bacterial evaluation in patients with periodontal disease, the dental plaque is the most suitable biological material, because it is the richest in periodontal bacteria.

[Clinical impact of platelet rich plasma in treatment of gingival recessions].

INTRODUCTION: Root coverage supported with complete regeneration of lost periodontal tissues represents the ultimate goal of gingival recession treatment. OBJECTIVE: This study was designed to evaluate clinical effectiveness of platelet rich plasma gel (PRP) with connective tissue graft (CTG) in the treatment of gingival recession. METHOD: 15 gingival recessions Miller class I or II were treated with CTG and PRP (group PRP). Connective tissue graft was harvested from the premolar region using trap door technique. After elevation of the flap, the regional bone and root surface were smeared with activated PRP gel. CTG was also irrigated with PRP gel before placement over the exposed root surface and local bone. Fixed CTG was covered with a coronally advanced flap. The same number of gingival recessions were treated with CTG in combination with the coronally advanced flap with no PRP gel (group TVT). Clinical recordings included recession depth (RD), probing depth (PD), clinical attachment level (CAL) and keratinized tissue width (KT) before and 1 year after mucogingival surgical treatment. RESULTS: Mean value of RD was significantly decreased from 4.93 +/- 0.86 mm to 0.60 +/- 0.37 (p < 0.01) with CTG and PRP and from 4.76 +/- 0.74 mm to 0.63 +/- 0.29 mm (p < 0.01) in CTG group. This difference was not statistically significant. Results of the keratinized tissue width showed significant increase from 0.88 +/- 0.30 mm presurgery to 3.78 +/- 0.49 mm (p < 0.01) six months after treatment in PRP group and from 0.90 +/- 0.34 mm to 3.15 +/- 0.41 in TVT group (p < 0.01). This difference was statistically significant (p > 0.05). No statistically significant differences were observed between treatment groups in CAL and PD. CONCLUSION: Clinical results validate both procedures as effective and highly predictable surgical techniques in solving gingival recession problem. Histological evaluation may confirm advantage of PRP use related to regeneration of periodontal tissues.

Correlation between atherosclerosis and periodontal putative pathogenic bacterial infections in coronary and internal mammary arteries.

BACKGROUND: Chronic infections, such as periodontitis, have been associated with an increased risk for atherosclerosis and coronary artery disease. The aim of this study was to investigate biopsy samples of coronary and internal mammary arteries for the presence of putative pathogenic bacteria (Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Tannerella forsythensis), Chlamydia pneumoniae, and human cytomegalovirus (CMV). METHODS: Patients with a diagnosis of coronary artery disease were included in the study. Fifteen coronary arteries with atherosclerosis and 15 internal mammary arteries without clinically assessable atherosclerotic degeneration were investigated. Both groups of specimens were obtained during coronary artery bypass grafting surgery. In all cases, the coronary and mammary artery specimens were taken from the same patient. The detection of periodontal pathogens, C. pneumoniae, and CMV was done by polymerase chain reaction analysis. RESULTS: Bacterial DNA was found in nine of 15 (60%) coronary artery biopsy samples: P. gingivalis in eight (53.33%), A. actinomycetemcomitans in four (26.67%), P. intermedia in five (33.33%), and T. forsythensis in two (13.33%) samples; CMV was detected in 10 (66.67%) samples, and C. pneumoniae was detected in five (33.33%) samples. Some of the samples contained more than one type of bacteria. Periodontal pathogens were not detected in internal mammary artery biopsies, whereas CMV was present in seven (46.67%) samples and C. pneumoniae was present in six (40%) samples. CONCLUSION: The absence of putative pathogenic bacteria in internal mammary arteries, which are known to be affected rarely by atherosclerotic changes, and their presence in a high percentage of atherosclerotic coronary arteries support the concept that periodontal organisms are associated with the development and progression of atherosclerosis.

Bone apposition to titanium implants biocoated with recombinant human bone morphogenetic protein-2 (rhBMP-2). A pilot study in dogs.

The aim of the present study was to investigate bone formation to recombinant human bone morphogenetic protein-2 (rhBMP-2)-biocoated and rhBMP-2-nonbiocoated titanium implants after implantation in dogs. Implantation of sand-blasted and acid-etched (C), chromosulfuric acid surface-enhanced (CSA), and rhBMP-2-biocoated CSA [BMP-A: noncovalently immobilized rhBMP-2 (596 ng/cm(2)), BMP-B: covalently immobilized rhBMP-2 (819 ng/cm(2))] implants was performed in both the mandible and tibia of dogs. After 4 weeks of healing, the percentage of direct bone to implant contact (BIC) and the induced bone density (BD) at a distance of less than and greater than 1 mm adjacent to each implant was assessed. Histomorphometric analysis of implants inserted in the mandible and tibia revealed that BIC values appeared to be highest in the BMP-B group, followed by BMP-A, CSA, and C. BD as measured at a distance of <1 mm revealed obvious differences between groups: BMP-B>BMP-A>CSA>C. However, no differences between groups were observed at a distance of >1 mm. Within the limits of the present study, it may be concluded that rhBMP-2 immobilized by covalent and noncovalent methods on CSA-treated implant surfaces seemed to be stable and promoted direct bone apposition in a concentration-dependent manner.

Histomorphometric and fluorescence microscopic evaluation of interfacial bone healing around 3 different dental implants before and after radiation therapy.

PURPOSE: Radiation therapy influence on bone healing around 3 types of endosseous dental implants in dogs was evaluated. MATERIALS AND METHODS: Implants with 3 different surfaces (A = machined commercially pure titanium screws, B = commercially pure titanium plasma spray-coated cylinders, C = hydroxyapatite [HA] -ceramic coated cylinders) were first implanted unilaterally into the right posterior edentulous mandibles of 7 dogs as nonirradiated controls. After 12 weeks without functional loading and after sequential fluorochrome labeling these implants were retrieved by block dissection. In this same surgery, implants were placed on the contralateral side. Three weeks postimplantation the implant-containing hemimandibles were Cobalt 60 irradiated with the biologic equivalent of 5,000 cGy. Twelve weeks postimplantation and after labeling these irradiated implants were retrieved at sacrifice. On scanning electron, light, and fluorescence microscopic images of undecalcified longitudinal ground sections of the implants with surrounding tissues, percent bone-to-implant contact (% BIC), bone formation, and remodeling were histometrically and subjectively evaluated. RESULTS: Woven bone formation started 1 week after implantation at the implant interfaces on both the nonirradiated and the irradiated sides. Average BICs (total/cortical/spongious bone bed) of 26%/49%/36% for surface A, 46%/48%/64% for surface B, and 81%/83%/78% for surface C were observed. In the irradiated hemimandibles average BICs (total/cortical/spongious bone bed) were reduced to 11%/9%/4% for surface A, 43%/46%/43% for surface B, and 63%/85%/76% for surface C, with increased resorption of peri-implant bone and retarded bone formation after irradiation. DISCUSSION: Reductions of total % BIC in all irradiated implants, though not statistically significant, were significant (P < or = .05) on implant surfaces A and B in the spongious bone bed. CONCLUSION: Retarded bone formation on surfaces A and B in the spongious bone bed represented a more radiation-sensitive situation at the time of radiation onset compared to advanced bone formation and maturation at surface C.

A reentry study on the use of bovine porous bone mineral, GTR, and platelet-rich plasma in the regenerative treatment of intrabony defects in humans.

This study compared the clinical effectiveness of a combination therapy consisting of bovine porous bone mineral (BPBM), guided tissue regeneration (GTR), and platelet-rich plasma (PRP) in the regeneration of periodontal intrabony defects in humans. Twenty-eight paired intrabony defects were surgically treated using a split-mouth design. Defects were treated with BPBM, GTR, and PRP (experimental), or with open-flap debridement (control). Clinical parameters evaluated included changes in attachment level, pocket depth, and defect fill as revealed by reentry at 6 months. Preoperative pocket depths, attachment levels, and transoperative bone measurements were similar for the two groups. Postsurgical measurements taken at 6 months revealed that both treatment modalities significantly decreased pocket depth and increased clinical attachment and defect fill compared to baseline. The differences between the experimental and control groups were 2.22+/-0.39 mm on buccal and 2.12+/-0.34 mm on lingual sites for pocket depth, 3.05+/-0.51 mm on buccal and 2.88+/-0.46 mm on lingual sites for gain in clinical attachment, and 3.46+/-0.96 mm on buccal and 3.42+/-0.02 mm on lingual sites for defect fill. These differences between groups were statistically significant in favor of the experimental defects. The combined therapy was also clinically more effective than open-flap debridement. The superiority of the experimental group could not be attributed solely to the surgical intervention and was likely a result of the BPBM/GTR/ PRP application. Combining BPBM, GTR, and PRP was an effective modality of regenerative treatment for intrabony defects in patients with advanced periodontitis.

Alveolar bone preservation following tooth extraction: a perspective of clinical trials utilizing osseous grafting and guided bone regeneration.

Based on data from the authors' three clinical trials that focused on the role exerted by various regenerative materials and techniques in preserving alveolar ridge dimensions following tooth extraction, there is evidence to support the use of nonresorbable and resorbable membranes in combination with a closed-socket approach. There also is evidence to support a higher predictability of the results with resorbable membranes compared with nonresorbable membranes because the latter can become exposed to the oral environment during healing. A combination of bioactive glass and calcium sulfate using an open-socket approach is of marginal benefit in preserving alveolar ridge dimensions following tooth extraction. More research is necessary on combining osseous graft/guided bone regeneration using a closed-socket approach, on assessing the quality of bone present in the previous extraction socket following various preservation techniques, and on how effectively preserved/regenerated bone supports dental implants.

Effectiveness of a combination of platelet-rich plasma, bovine porous bone mineral and guided tissue regeneration in the treatment of mandibular grade II molar furcations in humans.

OBJECTIVE: A combination of platelet-rich plasma (PRP), bovine porous bone mineral (BPBM) and guided tissue regeneration (GTR) has been shown to be effective as regenerative treatment for intrabony periodontal defects. The purpose of this study was to evaluate the effectiveness of PRP, BPBM and GTR used in combination as regenerative treatment for grade II molar furcation defects in humans. MATERIAL AND METHODS: Using a split-mouth design, a total of 52 grade II mandibular molar furcation defects were treated either with PRP/BPBM/GTR (experimental group, n=26) or with an open flap debridement (control group, n=26). The primary outcomes evaluated in this study included changes in pocket depth, attachment level and re-entry bone levels (horizontal and vertical) between baseline and 6 months postoperatively. RESULTS: The results showed that the experimental group presented with significantly greater pocket reduction (4.07+/-0.33 mm for experimental and 2.49+/-0.38 mm for control sites), gain in clinical attachment (3.29 +/- 0.42 mm for experimental and 1.68+/-0.31 mm for control sites), vertical defect fill (2.56+/- 0.36 mm for experimental and -0.19+/-0.02 for control sites) and horizontal defect fill (2.28+/-0.33 mm for experimental and 0.08+/-0.02 mm for control sites) than the control group. CONCLUSIONS: It was concluded that the PRP/BPBM/GTR combined technique is an effective modality of regenerative treatment for mandibular grade II furcation defects. Further studies are necessary to elucidate the role played by each component of the combined therapy in achieving these results.