Prevalence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia in Japanese patients with generalized chronic and aggressive periodontitis.

This study aimed to investigate the prevalence and levels of major periodontal pathogens, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia in subgingival plaque samples of a group of Japanese patients with aggressive periodontitis (AgP) and chronic periodontitis (CP). A total of 40 patients with clinical diagnosis of AgP or CP and 10 periodontally healthy volunteers were subjected to clinical and microbiological analysis. Subgingival plaque samples were analyzed for A. actinomycetemcomitans, P. gingivalis and T. forsythia with a real-time polymerase chain reaction (PCR) technique. The prevalence of P. gingivalis and T. forsythia was relatively high in patients with periodontitis: over 60% of AgP or CP patients harbored these pathogens whereas they were not detected in the subgingival plaque samples from periodontally healthy individuals. P. gingivalis and T. forsythia were relatively frequently detected together in AgP and CP patients. No significant differences in the prevalence or level of the 3 pathogens were found between periodontitis groups. The proportion of T. forsythia was approximately 4-fold higher in CP group than in AgP group (P = 0.02). In periodontitis patients, a significant positive correlation was found between periodontal parameters (probing depth and clinical attachment level) and the numbers of total bacteria, P. gingivalis and T. forsythia. No distinct pattern of the subgingival profile of these pathogens was discerned between the two disease entities, except for the difference in the proportion of T. forsythia. The red complex bacteria, P. gingivalis and T. forsythia were highly prevalent in this population of Japanese AgP and CP patients, collaborating their roles in periodontitis.

Effect of basic fibroblast growth factor (FGF-2) in combination with beta tricalcium phosphate on root coverage in dog.

OBJECTIVE: In root coverage treatment, periodontal regeneration in gingival recession-type defects is an important challenge for the periodontist. The aim of this study was to histometrically investigate the effect of combined use of basic fibroblast growth factor (FGF-2) and beta tricalcium phosphate (ß-TCP) on root coverage in dogs. MATERIALS AND METHODS: Sixteen adult beagle dogs were used. Buccal gingival recession defects were surgically created bilaterally in the maxillary canines. The defects in each animal were randomly assigned to: (1) an FGF-2 alone (control) group or (2) FGF-2/ß-TCP (experimental) group. At 2, 4 or 8 weeks following surgery, specimens were obtained and subjected to microscopic examination and histometric assessment. RESULTS: Inhibition of epithelial down-growth was observed in both groups. At week 2, in the newly formed connective tissue at the coronal portion, the FGF-2/ß-TCP group showed significantly greater numbers of proliferating cell nuclear antigen-positive cells than the FGF-2 group (55.8 ± 4.8 vs 12.0 ± 1.4, p < 0.01). In the FGF-2/ß-TCP group, new attachment was observed at 8 weeks and the extent of new bone and cementum formation was significantly greater in the FGF-2/ß-TCP group than that in the FGF-2 alone group. In both groups, the dentin surface beneath the new cementum presented minor irregularities, but no replacement resorption was observed. CONCLUSIONS: FGF-2 used in combination with ß-TCP enhances formation of new bone and cementum without significant root resorption in root coverage in this dog model. This combination warrants further investigation in periodontal regeneration in root coverage treatment.

A collaborative approach to care for patients with periodontitis and diabetes.

As periodontal disease and diabetes mellitus (DM) have bidirectional interactions, an effective approach to periodontal treatment for patients with diabetes in the clinical setting is essential. This paper reports an effort in collaborative care for patients with periodontitis and diabetes between dental and medical professionals, and provides a preliminary evaluation regarding the clinical outcomes. We have introduced a clinical pathway program at our institution applicable to patients with periodontitis and DM. Physicians and dentists utilize the clinical pathway to share medical and dental information in order to provide the optimal care for each patient. So far, this clinical pathway has been applied to the treatment of 50 patients. We analyzed clinical outcomes in 10 patients with the chief complaint of periodontal problems who had also been diagnosed with type 2 DM. After initial periodontal therapy and diabetes care, a significant improvement in the mean value of glycated hemoglobin and fasting plasma glucose was observed, accompanied by clinical resolution of periodontal parameters. Within the limitations of the present study, the results suggest that collaborative care between periodontists and physicians based on the clinical pathway is effective in glycemic control of patients with periodontitis and type 2 DM. This indicates the need for closer collaboration between medical and dental professionals in improving the management of these diseases.

Effect of platelet-derived growth factor-BB on root resorption after reimplantation of partially denuded tooth in dog.

The prognosis for a reimplanted tooth depends largely on the condition of the root. Platelet-derived growth factor (PDGF)-BB has been shown to regenerate periodontal tissue in animal and human clinical studies. However, information regarding the effect of PDGF-BB on tooth reimplantation is limited. The objective of this study was to investigate the effect of PDGF-BB on root resorption after reimplantation of a partially denuded tooth in dog. A total of 15 healthy female beagle dogs were used. Mandibular third and fourth premolars were endodontically treated and then extracted as atraumatically as possible. The coronal portion of each root was carefully scaled and planed. The roots on the right side of the mandible were treated with PDGF-BB and reimplanted, while the roots on the left side served as controls. After 2, 4, or 8 weeks, specimens were collected and processed for histopathological examination. By the 4th week after reimplantation, new periodontal ligament (PDL)-like tissue had formed around the PDGF-BB-treated root surfaces and new bone. By the 8th week, healing of the PDGF-BB-treated roots was characterized by newly formed PDL with inserting attachment formation. In contrast, control roots showed multiple areas of replacement resorption. Immunohistochemical staining of proliferating cell nuclear antigen (PCNA) performed at 2 weeks after reimplantation showed that the number of PCNA-positive cells in the connective tissue area was statistically significantly greater in the PDGF-BB-treated group than in the control group (P < 0.001). The application of PDGF-BB resulted in a significantly lower occurrence and extent of root resorption and ankylosis. These results suggest that the use of PDGF-BB reduces occurrence of ankylosis and root resorption in tooth reimplantation.

Coverage of gingival recession defects using guided tissue regeneration with and without adjunctive enamel matrix derivative in a dog model.

The aim of this study was to clarify the adjunctive effect of enamel matrix derivative (EMD) on expanded polytetrafluoroethylene membrane guided tissue regeneration (GTR)-based root coverage by creating gingival recessions in beagle dogs. Recessions were treated with GTR + EMD, GTR alone, or neither GTR nor EMD (control). The control group was characterized by long junctional epithelium and little bone formation. The GTR + EMD group showed a statistically significant increase (P < .01) in new bone and cementum formation compared with the GTR group. The results of the present investigation suggest that the adjunctive use of EMD with GTR promotes formation of new bone and cementum without root resorption in recession-type defects in dogs.

C-Graft in regeneration of periodontal tissue in intrabony periodontal defect in dog.

The aim of this study was to investigate the effect of C-Graft particles on formation of new cementum and bone in periodontal bone defects in dog. Healing and tissue change were histologically determined at 2, 4, 8, and 16 weeks. Little bone or cementum formation was observed in the control group. A statistically significant increase in bone and cementum formation was seen in the C-Graft group compared to the control group (75.4% vs. 44.9%, p < 50.01, 80.4% vs. 46.7%, p < 50.05, respectively). These findings suggest that C-Graft particles provide a scaffold for the regeneration of new bone and cementum.

Beta-tricalcium phosphate and basic fibroblast growth factor combination enhances periodontal regeneration in intrabony defects in dogs.

The combined effect of beta-tricalcium phosphate and basic fibroblast growth factor was observed in the regeneration of periodontal tissue in dogs. For this purpose, either beta-TCP and FGF-2 (beta-TCP/FGF-2 group) or FGF-2 alone (FGF-2 group) was applied in intrabony defects. The control group received beta-TCP alone. The tissues were histologically examined at 2, 4, or 8 weeks following treatment. The control group was characterized by incomplete, newly formed bone around beta-TCP particles. The beta-TCP/FGF-2 group showed a statistically significant increase in both new bone and cementum formation compared to the FGF-2-alone group (76.3% vs. 65.3%, p < 0.01; 81.0% vs. 68.3%, p < 0.01, respectively). These findings suggested that beta-TCP may be a suitable scaffold for FGF-2 and that the combination of beta-TCP and FGF-2 can enhance bone and cementum formation.

Transplantation of human tooth with proliferating periodontal tissue--long-term clinical follow-up study--.

A case report is presented on transplantation of a left third molar to replace a right second molar lost due to large furcation perforation. Two weeks after surgery, a reentry surgical procedure was performed on the furcation defect of the second molar to remove membrane and retrieve proliferating periodontal tissue. The left third molar and proliferating periodontal tissue were then transplanted into the bone defect of the right second molar. Radiographically, the transplanted tooth showed no root resorption over a 3-year period. The results indicate that teeth replanted with proliferating periodontal tissue have a favorable long-term prognosis.

Effectiveness of proliferating tissues in combination with bovine-derived xenografts to intrabony defects of alveolar bone in dogs.

The aim of this study was to investigate the effect of proliferating tissue used in combination with bovine-derived xenograft (BDX) on the formation of new cementum and bone in dogs. Intrabony defects were treated with either BDX in conjunction with autogenous proliferating tissues (BDXplus-proliferating tissues: BDX-P group) or BDX alone (BDX-alone group). The control group received no BDX or proliferating tissues. The animals were sacrificed after 2, 4, and 8 weeks of the treatment, and tissues were histologically examined. Specimens from the control group were characterized by long junctional epithelium and little bone formation. The BDX-P group showed a statistically significant increase in new bone and cementum formation compared to the BDX-alone group (30.9% vs. 18.7, p < 0.01 and 87.8% vs. 61.8, p < 0.01). The ratio of proliferating cell nuclear antigen (PCNA)-positive cells in the newly formed connective tissue of the BDX-P group was significantly greater than that in the BDX-alone group. These findings suggest that the use of proliferating tissues in combination with BDX enhances new bone and cementum formation, offering potential as therapeutic material in periodontal regeneration.

Periodontal regeneration following transplantation of proliferating tissue derived from periodontal ligament into class III furcation defects in dogs.

The aim of this study was to evaluate the healing of class III furcation defects following transplantation of proliferating tissue derived from periodontal ligament (pPDL). Two weeks after removing alveolar bone, pPDL was excised. Class III furcation defects were created in the mandibular premolars. pPDL was transplanted into the furcation defects in the experimental group, while no treatment was performed on the furcation defects in the controls. Two, four and eight weeks after surgery, histologic examination, quantitative RT-PCR, and immunohistochemistry were carried out. bFGF and VEGF mRNA showed a significant increase in pPDL. In the pPDL treatment group, new cementum regenerated around almost the entire circumference of the furcation, with new bone filling most of the defect, while the control group presented epithelial downgrowth and defects filled with connective tissue. These results provide histological evidence that pPDL plays an important role in wound healing by promoting periodontal regeneration in class III furcation defects.

Analgesic efficacy of celecoxib in patients after oral surgery: special reference to time to onset of analgesia and duration of analgesic effect.

PURPOSE: Cyclooxygenase-2 inhibitor celecoxib is also used in the dental field for analgesia. However, there are few reports on the time to onset and duration of analgesia. We investigated the analgesic effect of celecoxib after oral surgery. METHODS: A total of 138 patients undergoing unilateral mandibular third molar surgery under local anesthesia were enrolled. After surgery, the patients who felt pain and requested an analgesic were instructed to take celecoxib 400 mg and to record the time. Primary efficacy outcome measures were time to onset of analgesia. In addition, the conditions of pain at the time of taking celecoxib, at the onset time of analgesia, and 2 and 6 h after taking the drug were recorded. Pain assessments were evaluated using a 10-cm visual analog scale and four-point verbal rating score. These data were documented in the questionnaire forms handed to the patients and retrieved by post. RESULTS: Effective responses without missing were returned from 103 patients. The median time to onset of the efficacy was 35 min. The pain scales at celecoxib administration was significantly higher compared with the time of onset of analgesia, 2 hours after administraton and 6 hours hours administration (P<0.05, respectively). The pain scales at the onset time of analgesia were significantly higher compared to that after 2 or 6 h of taking the drug (P<0.05, respectively). There were no statistically significant differences in the pain scales between 2 and 6 h after taking the drug (P>0.05). CONCLUSION: The analgesic effect of celecoxib was exhibited quickly and sustained after oral surgery.

Periodontal regeneration in intrabony defects after application of enamel matrix proteins with guided tissue regeneration: an experimental study in dogs.

The aim of this study was to evaluate the effects of enamel matrix proteins (EMP) at the early stage of wound healing in the periodontal tissues by a combination treatment with guided tissue regeneration (GTR). Intrabony defects were produced surgically at the distal aspects of both mandibles in six beagle dogs. At 12 weeks following the surgery, the defects were exposed using a full thickness mucoperiosteal flap procedure. Subsequently, the defects were treated by the following treatments: a control group treated with GTR alone, and an experimental group treated with a combination of GTR and EMP. After one, two, four and eight weeks of the treatment, the animals were sacrificed, and sections of the tissue were stained and evaluated microscopically. After one and two weeks, the proliferating cell nuclear antigen (PCNA)-positive cell ratios of the experimental group were significantly greater than that of the control group. After 2 and 4 weeks, new bone and new cementum formation in the experimental group were significantly greater than those in the control group (P < 0.05). However, after 8 weeks, no statistical difference was found between the two groups in new bone or cementum formation. The study results suggest that a maturation of periodontal ligament cells might contribute, during the early stage of periodontal healing, to stimulate a proliferation of periodontal ligament cells.

Gene expression analysis of the lung following paraquat administration in rats using DNA microarray.

Gene expression changes in the lungs induced by paraquat (PQ) administration were studied in rats using DNA microarrays that were detectable for 1,090 genes per DNA microarray. The rats were subjected to subacute PQ exposure (7 mg/kg, s.c., daily for eight administrations). Two days after the final administration, the rats were divided into two groups. Group 1 experienced significant body weight loss and displayed signs of subacute PQ toxicity, but Group 2 showed no significant effects due to the PQ treatment. A control group, Group 3, was also included. In the comparison of the gene expression levels in the animals from Group 1 or Group 2 to the control animals treated by vehicle, 48 genes in Group 1 and 29 genes from Group 2 were differentially expressed. The twenty-eight genes were common to these two groups. These differentially expressed genes following paraquat treatment were classified as follows: 5 neurotransmitter receptor genes; 4 transporter genes; 4 voltage-gated ion channel genes; 2 lipid metabolism enzyme genes; 2 G-proteins involved in endocytosis and exocytosis genes; 7 cytokine genes; 4 ADP ribosylation genes involved in cell death and regeneration; CFTR gene, which is the causal gene for cystic fibrosis; neurofibromatosis type 1 gene, which is the causal gene for the neurofibromatosis type 1 that is known to accompany pulmonary fibrosis; and the causal gene for spinocerebellar ataxia. These genes may prove to be the keys for the elucidation of the mechanism of PQ toxicity, e.g. PQ-induced pulmonary fibrosis.

Evaluation of a poly-l-lactic acid membrane and membrane fixing pin for guided tissue regeneration on bone defects in dogs.

OBJECTIVES: The purpose of the study was to clarify the usefulness of a poly-l-lactic acid and membrane fixing pin, used in combination with guided bone regeneration, on bone defects in dogs. STUDY DESIGN: Osteotomies bone defects were created in 8 beagle dogs. Group I: one defect was covered with test membrane and held by fixing pins. Group II: the other defect was covered test membrane and not held by fixing pins. The control group received no membrane. The dogs were killed after 24 or 36 weeks of healing. Sections were stained and evaluated microscopically. Data were analyzed statistically. RESULTS: The degradation and resorption of test membrane was not observed at 24 weeks but was noted at 36 weeks. After 24 and 36 weeks, most of Group I defects were completely closed with new bone, while in the control defects, only a small amount of new bone was observed at the bottom of the bone defects. After 36 weeks, the percentage of new bone volume (62.2%) in the space beneath the test membrane and membrane fixing pin (Group I) was greater than that without a membrane fixing pin-53.2% (Group II), whereas only 43.9% of the defect area in the control group was filled with new bone. CONCLUSION: The results of this study show that a poly-l-lactic acid membrane and membrane fixing pin permit bone regeneration that can be ensured by excluding surrounding soft tissues from the wound area.

Coverage of gingival recession defects using acellular dermal matrix allograft with or without beta-tricalcium phosphate.

The aim of this study was to investigate the effect of beta-tricalcium phosphate (ß-TCP) particles in combination with acellular dermal matrix (ADM) allograft in gingival recession. Experimental gingival recession defects were created in beagle dogs and randomly assigned to one of the following groups: ADM, ADM + ß-TCP, or coronally positioned flap (CPF; control). Tissues were histologically examined at 4, 8, or 16 weeks following treatment. A greater thickness of gingiva was observed at the sites treated in both the ADM + ß-TCP and ADM groups than in the CPF group. The ADM + ß-TCP group showed a statistically significant increase in both new bone and cementum formations compared to the ADM group. The results suggest that the combination of ß-TCP and ADM is more effective in promoting new bone and cementum formations than ADM graft alone.

Effect of basic fibroblast growth factor on root resorption after delayed autotransplantation of tooth in dogs.

OBJECTIVES: The aim of this study was to investigate the effect of basic fibroblast growth factor (FGF-2) on root resorption after delayed autotransplantation in dogs. STUDY DESIGN: Mandibular second and third premolars of beagle dogs were extracted to create sites for autotransplantation. After 2 months, in the experimental sites the first and fourth mandibular premolars were extracted and air dried before autotransplantation with the application of recombinant FGF-2; the control sites received teeth without FGF-2. At 2, 4, or 8 weeks after surgery, the animals were killed and specimens collected and processed for histologic examination. RESULTS: Autotransplantation with FGF-2 yielded formation of new periodontal ligament-like tissues with inserting collagen fibers, associated cementum, and bone. The occurrence of replacement resorption in the FGF-2 treated group was significantly lower than in the control group (P < .01). CONCLUSIONS: It was demonstrated that topical application of FGF-2 reduced the occurrence of ankylosis and root resorption after delayed autotransplantation in this experimental model.

Effect of recombinant basic fibroblast growth factor on reimplanted teeth in beagle dogs.

OBJECTIVES: This study assessed the effect of recombinant fibroblast growth factor (FGF-2) on reimplanted teeth. STUDY DESIGN: Premolars were reimplanted in dogs. Roots on the left side of the mandible were treated with FGF-2, whereas roots on right side served as controls. At 2, 4, or 8 weeks after treatment, animals were humanely killed and specimens collected and processed for histopathologic examination. RESULTS: After 2 weeks, proliferating cell nuclear antigen-positive cell ratios in the experimental group were significantly greater than those in the control group (P < .01). After 4 and 8 weeks, the experimental group showed formation of new cementum. Moreover, incidence of replacement resorption in the experimental group was significantly lower than that in the control group (P < .01). CONCLUSION: The results indicate that FGF-2 promotes formation of new periodontal ligament and prevents ankylosis and root resorption following reimplantation of teeth.

Effect of ß tricalcium phosphate particle size on recombinant human platelet-derived growth factor-BB-induced regeneration of periodontal tissue in dog.

The aim of this study was to investigate the effect of ß tricalcium phosphate (ß-TCP) particle size on recombinant human platelet-derived growth factor-BB (rhPDGF-BB)-induced regeneration of periodontal tissue in dog. The control group (rhPDGF-BB alone) was characterized by incomplete, newly formed bone. The large-particle ß-TCP (L-TCP(O))/rhPDGF-BB group showed a statistically significant increase in both new bone and cementum formation compared to the small-particle ß-TCP (S-TCP(G))/rhPDGF-BB group. These findings suggest that L-TCP(O)-particle promotes rhPDGF-BB-induced formation of bone and cementum.

Effect of proliferating tissue on transplanted teeth in dogs.

OBJECTIVE: The objective of this study was to investigate the effect of transplanted proliferating tissue on the regeneration of periodontal ligaments (PDL) in tooth transplantation. STUDY DESIGN: Two weeks after removing the alveolar bone, proliferating tissues were excised and examined for expression of basic fibroblast growth factor (bFGF) and alkaline phosphatase (ALP) using a LightCycler. Next, the teeth to be transplanted (first premolars) were extracted and PDLs were removed by scaling. After that, the first premolar teeth and proliferating tissues for the experimental group were transplanted into bone cavities created at the sites of the third and fourth premolars, while the control sites received teeth only. Finally, 1, 2, and 4 weeks later, the animals were sacrificed and specimens were collected and processed for histopathologic examination. RESULTS: bFGF and ALPmRNA showed a significant increase in the transplanted proliferating tissue. Transplantation of the proliferating tissues positively affected the formation of new cementum and PDL. Moreover, application of the transplanted proliferating tissues decreased the occurrence and extent of ankylosis and root resorption at the root surface. CONCLUSION: These results indicate that transplanted proliferating tissue may promote the regeneration of periodontal tissue and prevent ankylosis and root resorption following the transplantation of teeth.