Green tea extract inhibits the onset of periodontal destruction in rat experimental periodontitis.

BACKGROUND AND OBJECTIVE: Green tea extract exerts a variety of biological effects, including anti-inflammatory activities. However, there has been no report on the effect of green tea extract on loss of attachment, which is an important characteristic of periodontitis. Here, we examined the inhibitory effects of green tea extract on the onset of periodontitis in a rat model. MATERIAL AND METHODS: Rats were immunized intraperitoneally with Escherichia coli lipopolysaccharide (LPS). The LPS group (n = 12) received a topical application of LPS onto the palatal gingival sulcus every 24 h. The green tea extract group (n = 12) received a topical application of LPS mixed with green tea extract, sunphenon BG, every 24 h. The phosphate-buffered saline (PBS) group (n = 6) received a topical application of PBS every 24 h. The levels of anti-LPS immunoglobulin G (IgG) in serum were determined using ELISA. Rats in the LPS and green tea extract groups were killed after the 10th and 20th applications. Rats in the PBS group were killed after the 20th application. Loss of attachment, level of alveolar bone and inflammatory cell infiltration were investigated histopathologically and histometrically. RANKL-positive cells and the formation of immune complexes were evaluated immunohistologically. RESULTS: There was no significant difference in the serum levels of anti-LPS IgG between the LPS group and the green tea extract group. In contrast, loss of attachment, level of alveolar bone, inflammatory cell infiltration and RANKL expression in the green tea extract group were significantly decreased compared with those in the LPS group. CONCLUSION: These findings demonstrate that green tea extract suppresses the onset of loss of attachment and alveolar bone resorption in a rat model of experimental periodontitis.

Influence of anatomic features on the effectiveness of enamel matrix derivative proteins in the treatment of proximal Class II furcation involvements.

OBJECTIVES: To evaluate the influence of furcation anatomy and bone defect morphology on the treatment of Class II proximal furcations treated with enamel matrix derivative (EMD) proteins. METHOD AND MATERIALS: Eighteen Class II proximal furcations were treated with open-flap debridement + 24% EDTA conditioning + EMD proteins. Probing depth, gingival margin position, relative vertical and horizontal clinical attachment level, and vertical and horizontal bone levels were evaluated immediately before and 6 months after the surgeries. The changes in these parameters were correlated with vertical defect depth, number of walls, depth defect, interdental distance, root divergence, furcation distance, horizontal measure, root trunk, and furcation height, using the Pearson and Spearman rank correlation tests (a = 5%). RESULTS: The depth defect correlated with gingival margin position (r = 0.52; P = .03), probing depth (r = 0.63; P = .005), and horizontal bone level (r = -0.46; P = .05). The furcation height also correlated with gingival margin position (r = 0.53; P = .02) and horizontal bone level (r = -0.57; P = .01). Moreover, the number of walls of vertical defect positively influenced relative vertical clinical attachment level (r = 0.47; P = .05). CONCLUSIONS: Within the limits of this study, furcation anatomy and defect morphology influence the clinical response of EMD protein therapy in Class II proximal furcation involvements.

Effects of risedronate on alveolar bone loss and angiogenesis: a stereologic study in rats.

BACKGROUND: The present study was designed to evaluate the effects of risedronate, one of the most potent bisphosphonates, on alveolar bone resorption and angiogenesis in rats with experimental periodontitis to identify dose-response curves and treatment durations that can be therapeutic for periodontal therapy versus those associated with osteonecrosis of the jaws. METHODS: Thirty-five rats, 25 with experimental periodontitis (groups 1 through 5) and 10 with healthy periodontium (groups 6 and 7), were divided into seven equal groups: group 1 received no treatment; groups 2 and 3 received risedronate, 0.1 and 1 mg/kg, respectively, for 3 weeks; groups 4 and 5 received risedronate, 0.1 and 1 mg/kg, respectively, for 8 weeks; and groups 6 and 7 received 0.9% NaCl for 3 and 8 weeks, respectively. Animals in groups 2 through 7 were administered treatment 5 days per week. After histologic processing, histomorphometric and stereologic analyses were carried out to estimate the number of blood vessels (NBV) and the volumetric densities of bone (Vb), marrow (Vm), osteoblasts (Vob), and osteoclasts (Voc). RESULTS: A total of 0.1 and 1 mg/kg risedronate for 3 weeks (groups 2 and 3) significantly increased Vb and Vob and decreased Vm more prominently in group 2 (P <0.001), whereas 1 mg/kg risedronate for 8 weeks (group 5) induced no significant improvement in these parameters compared to group 1 (P >0.05). No significant decrease in Voc was found in drug-administered groups compared to group 1 (P >0.05). A significant decrease in NBV (P <0.01) and positive correlation between NBV and Vb (r(2) = 0.941; P = 0.006) were found only in group 5. CONCLUSION: A short duration of risedronate administration may be useful in inhibiting bone resorption in periodontitis, whereas excessive dosages of the drug administered in longer durations can lead to impairment of bone formation and angiogenesis.

The effects of EDTA gel conditioning exposure time on periodontitis-affected human root surfaces: surface topography and PDL cell adhesion.

OBJECTIVE: The purpose of this investigation was to study the surface topography of periodontally-affected human roots following EDTA gel application at different time periods with and without scaling and root planing. In addition, to assess any correlations between root surface changes following EDTA gel conditioning and periodontal ligament fibroblast adhesion. METHODS: Forty-eight teeth that had a labial probing depth and clinical attachment loss of more than 7mm were used in this study. Periodontally-affected teeth were randomly divided into 4 groups of 12 teeth in each. Furthermore, a sample group of 6 teeth, which had a healthy periodontium, were used to serve as the healthy control (G1). The second group (G2) served as a diseased treated control in which sample teeth were only scaled and root planed prior to immediate extraction. Teeth in the third group (G3) were conditioned with a pH neutral, 24% Ethylenediaminetetraacetic acid (EDTA gel), for 2 minutes without any scaling or root planing and immediately extracted. The teeth in the fourth group (G4) were scaled, root planed, and then conditioned with the EDTA gel preparation for 2 minutes before immediate extraction. Finally the teeth in the fifth group (G5) were conditioned with EDTA gel for 4 minutes following scaling and root planing and immediately extracted. Half the samples in each group were randomly selected and processed for SEM evaluation of the surface topography. The other half were prepared to assess PDL cell adhesion with PDL fibroblasts being cultured and seeded on the root surface for 24 hours then processed for SEM evaluation of the adherent cells. RESULTS: SEM evaluation of the root planed surfaces in G2 revealed the typical appearance of a smear layer. The root surfaces of all samples in G3 exhibited a uniform coating of calculus that was covered by a considerable amount of loosely attached material including residual plaque and debris. In G4 EDTA gel exposure for 2-minutes following scaling and root planing resulted in removal of the smear layer and a marked exposure of round to oval dentinal tubule orifices. Areas of bacterial accumulation were observed in 4 out of the 6 samples examined in this group. The root surfaces after the 4-minute EDTA gel application (G5) had a fibrillar texture associated with a marked decrease in the number and an increased diameter of the exposed dentinal tubule openings. With regard to PDL cell adhesion, the majority of the 2-minute EDTA gel conditioning on the non-instrumented samples in G3, showed a failure of cells to adhere to the diseased root surface. The examined samples in G4 showed a significant increase in the number of flat and round adherent cells when compared to the diseased control samples (G2) (P > or = 0.01). The G5 samples showed a significant increase in the number of flat cells when compared to G4 (P > or = 0.01). CONCLUSION: The present study confirms the capability of EDTA gel to remove a root surface associated smear layer and to expose a collagen matrix when it was applied after scaling and root planing. In addition, a positive correlation was found between time of EDTA gel conditioning and the degree of PDL cell adhesion. It appears from the present investigation that EDTA gel conditioning for 4 minutes provides the most desirable root surface to which maximum PDL cells can adhere and on which they can grow.

Effect of a collagen membrane enriched with fibronectin on guided tissue regeneration in dogs.

The present study was planned to assess the capacity of a resorbable collagen membrane enriched with fibronectin to prevent the apical migration of epithelium and to facilitate new attachment and new bone. Experimental osseous dehiscence defects were produced on the bilateral labial aspect of mandibular 2nd, 3rd and 4th premolar teeth in six mongrel dogs. Guided tissue regeneration therapy using collagen membranes, which were rehydrated with fibronectin solution, was performed on one quadrant (group A). In the contralateral quadrant, the same collagen membranes, but rehydrated only with saline (group B), were placed over the bony defects. The third premolar teeth, which were treated by open-flap debridement, served as control (group C). Flaps were positioned slightly coronally and sutured; sutures were removed 10 days later. The dogs were killed 30 days after reconstructive therapy. Tissue blocks containing the experimental and control teeth were excised, demineralized in EDTA, and embedded in paraffin. Histological and histometric evaluation revealed that all groups demonstrated similar effects on preventing the down-growth of epithelium and formation of new cementum and new bone. Collagen membranes were tolerated well within the tissues, and membrane remnants were identified at 30 days. In summary, this study indicated that in this dog model similar healing results could be achieved with a bovine type I collagen membrane with or without fibronectin solution and open-flap debridement.

Aggressive periodontitis: 5-year follow-up of treatment.

BACKGROUND: The hypothesis that in subjects with aggressive periodontitis, a long-term stability of periodontal health can be achieved following comprehensive mechanical/surgical and systemic antimicrobial therapy was tested in this prospective study. METHODS: Thirteen patients (36.9+/-7.4 years) with aggressive periodontitis were monitored before and up to 5 years following periodontal therapy. Clinical attachment levels (CAL) were assessed pretherapy, and at 3 months following completion of active periodontal therapy supplemented by amoxicillin plus metronidazole. All subjects were subsequently enrolled in a maintenance program and provided with supportive periodontal therapy with 3 to 4 appointments annually. Reexaminations were performed after 6 months and 1, 2, 3, 4, and 5 years. The data were analyzed using the method of generalized estimating equations (GEE) for CAL changes from baseline to the 3-month visit, and from completion of periodontal therapy to each annual visit up to the 5-year follow-up reappointment. RESULTS: During the 5-year study, all subjects strongly benefited from periodontal treatment. Between baseline and the 3-month reexamination, the CAL levels revealed a significant decrease of 2.23 mm (95% confidence interval [CI]: 1.77 to 2.69 mm; P < or =0.001). At the 5-year maintenance visit, the CAL changes ranged from -0.04 to +0.29 mm with no further statistically significant periodontal breakdown (P >0.05). Five years after surgery, 3.2% of the treated sites demonstrated a further CAL gain > or =3 mm. A stabilization (CAL -2 to +2 mm) occurred in 94.6% of the cases. The number of periodontal sites experiencing a breakdown varied from 5.3% at 6 months to 2.2% at 5 years. CONCLUSIONS: In aggressive periodontitis, comprehensive mechanical/surgical and antimicrobial therapy is an appropriate treatment regimen for long-term stabilization of periodontal health. In this study, periodontal disease progression was successfully arrested in 95% of the initially compromised lesions, while 2% to 5% experienced discrete or recurrent episodes of loss of periodontal support.

Root conditioning using EDTA gel as an adjunct to surgical therapy for the treatment of intraosseous periodontal defects.

The aim of this clinical study was to compare the treatment outcome following root surface conditioning using an EDTA gel preparation in conjunction with surgical therapy with that following conventional flap surgery in periodontal intraosseous defects. 36 patients, each of them contributing one intraosseous defect > or =4 mm in depth participated. Defect sites had a probing pocket depth > or =5 mm and bled on probing following hygienic treatment phase. No furcation involvement or endodontic complications were present. In the EDTA group, 18 consecutive patients, defects were treated by root conditioning with EDTA gel for 3 minutes in combination with surgical therapy. In the control group, 18 patients, conventional flap surgery was performed without root conditioning. Chlorhexidine rinsings 0.2% were prescribed following surgery for 2-3 weeks with modified oral hygiene instruction. A strict recall program was implemented including professional prophylaxis and oral hygiene reinforcement every 4-6 weeks until 6-month re-evaluation. Baseline probing pocket depths and defect depths of 7.1+/-1.3 mm and 6.9+/-1.6 mm in the EDTA group and 7.6+/-1.9 mm and 6.6+/-1.7 mm, respectively, in the control group were measured. 6-month clinical results showed a significant probing attachment level gain of 1.8+/-1.5 mm and 1.0+/-1.7 mm in the EDTA and control groups respectively. A probing bone gain of 1.0+/-1.3 mm in the EDTA group was measured with a non-significant gain of 0.4+/-1.2 mm in the control group. Radiographic analysis confirmed these results. There were no statistically significant differences in treatment outcome between the group treated by root conditioning in combination with flap surgery and conventional flap surgery alone.

Periodontal repair in intrabony defects treated with a calcium sulfate implant and calcium sulfate barrier.

THIS RANDOMIZED, CONTROLLED, CLINICAL STUDY was designed to evaluate outcome following surgical implantation of an allogeneic, freeze-dried, demineralized bone matrix-calcium sulfate (DBM+CS) composite with a CS barrier in intrabony periodontal defects. Twenty-six patients contributing 26 deep intrabony defects completed the study. Thirteen patients received the DBM+CS implant. Thirteen patients received gingival flap surgery alone (GFS; control). Clinical outcome was assessed at 6 and 12 months postsurgery. At 12 months postsurgery, probing depth (PD) reduction (mean +/-SD) for the DBM+CS and GFS group was to 4.3+/-0.5 and 3.0+/-1.3 mm; clinical attachment gain was to 2.9+/-0.8 and 1.7+/-1.5 mm; and probing bone level gain was to 2.9+/-1.4 and 1.2+/-1.2 mm, respectively. There were no apparent differences between evaluations at 6 and 12 months postsurgery. Clinical improvements were significantly different from presurgery for both groups at both observation intervals (P < 0.01). There were no significant differences between groups in PD reduction and clinical attachment gain. Probing bone level gain was significantly greater in the DBM+CS group compared to controls (P < 0.05). In summary, surgical implantation of DBM+CS with a CS barrier resulted in reduced PD and improved attachment levels comparable to that achieved by gingival flap surgery alone. However, gain in probing bone levels in deep intrabony periodontal pockets assessed by clinical parameters was greater than that observed by gingival flap surgery alone. These changes were noted at both 6 and 12 months after surgery. This regenerative technique needs further biologic evaluation before being generally accepted.

Factors associated with different responses to periodontal therapy.

In a study of the efficacy of modified Widman flap surgery and scaling and root planning accompanied by 1 of 4 systemic adjunctive agents, Augmentin, tetracycline, ibuprofen or placebo, it was observed that subjects differed in their response to therapy. The difference was only partially accounted for by the adjunctive agent employed. The purpose of the present investigation was to examine clinical and microbiological features in subjects who showed different levels of attachment change post-therapy. 40 subjects were subset into 3 groups based on mean attachment level change post-therapy. 10 poor response subjects showed mean attachment loss; 19 moderate response subjects showed mean attachment gain between 0.02-0.5 mm and 11 good response subjects showed a mean gain of attachment > 0.5 mm. Clinical parameters were measured at 6 sites per tooth both pre- and post-therapy. Microbiological samples were taken from the mesial aspect of each tooth and evaluated individually for their content of 14 subgingival taxa using a colony lift method and DNA probes. % of sites colonized by each species was computed for each subject both pre- and post-therapy. Significant differences were observed among treatment response groups for mean probing pocket depth, attachment level and % of sites with plaque pre-therapy. The poor response subjects had the lowest mean probing pocket depth and attachment level, but the highest plaque levels. Post-therapy, the poor response group exhibited the greatest degree of gingival inflammation as assessed by gingival redness and bleeding on probing.(ABSTRACT TRUNCATED AT 250 WORDS)