Assessing the progression of chronic periodontitis using subgingival pathogen levels: a 24-month prospective multicenter cohort study.

BACKGROUND: The diagnosis of the progression of periodontitis presently depends on the use of clinical symptoms (such as attachment loss) and radiographic imaging. The aim of the multicenter study described here was to evaluate the diagnostic use of the bacterial content of subgingival plaque recovered from the deepest pockets in assessing disease progression in chronic periodontitis patients. METHODS: This study consisted of a 24-month investigation of a total of 163 patients with chronic periodontitis who received trimonthly follow-up care. Subgingival plaque from the deepest pockets was recovered and assessed for bacterial content of Porphyromonas gingivalis, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans using the modified Invader PLUS assay. The corresponding serum IgG titers were measured using ELISA. Changes in clinical parameters were evaluated over the course of 24 months. The sensitivity, specificity, and prediction values were calculated and used to determine cutoff points for prediction of the progression of chronic periodontitis. RESULTS: Of the 124 individuals who completed the 24-month monitoring phase, 62 exhibited progression of periodontitis, whereas 62 demonstrated stable disease. The P. gingivalis counts of subgingival plaque from the deepest pockets was significantly associated with the progression of periodontitis (p < 0.001, positive predictive value = 0.708). CONCLUSIONS: The P. gingivalis counts of subgingival plaque from the deepest pockets may be associated with the progression of periodontitis.

Periodontal tissue engineering by nano beta-tricalcium phosphate scaffold and fibroblast growth factor-2 in one-wall infrabony defects of dogs.

BACKGROUND AND OBJECTIVE: Nanoparticle bioceramics are being investigated for biomedical applications. We fabricated a regenerative scaffold comprising type I collagen and beta-tricalcium phosphate (ß-TCP) nanoparticles. Fibroblast growth factor-2 (FGF-2) is a bioeffective signaling molecule that stimulates cell proliferation and wound healing. This study examined the effects, on bioactivity, of a nano-ß-TCP/collagen scaffold loaded with FGF-2, particularly on periodontal tissue wound healing. MATERIAL AND METHODS: Beta-tricalcium phosphate was pulverized into nanosize particles (84 nm) and was then dispersed. A nano-ß-TCP scaffold was prepared by coating the surface of a collagen scaffold with a nanosize ß-TCP dispersion. Scaffolds were characterized using scanning electron microscopy, compressive testing, cell seeding and rat subcutaneous implant testing. Then, nano-ß-TCP scaffold, nano-ß-TCP scaffold loaded with FGF-2 and noncoated collagen scaffold were implanted into a dog one-wall infrabony defect model. Histological observations were made at 10 d and 4 wk postsurgery. RESULTS: Scanning electron microscopy images show that TCP nanoparticles were attached to collagen fibers. The nano-ß-TCP scaffold showed higher compressive strength and cytocompatibility compared with the noncoated collagen scaffold. Rat subcutaneous implant tests showed that the DNA contents of infiltrating cells in the nano-ß-TCP scaffold and the FGF-2-loaded scaffold were approximately 2.8-fold and 3.7-fold greater, respectively, than in the collagen scaffold. Histological samples from the periodontal defect model showed about five-fold greater periodontal tissue repair following implantation of the nano-ß-TCP scaffold loaded with FGF-2 compared with the collagen scaffold. CONCLUSION: The ß-TCP nanoparticle coating strongly improved the collagen scaffold bioactivity. Nano-ß-TCP scaffolds containing FGF-2 are anticipated for use in periodontal tissue engineering.

Salivary pathogen and serum antibody to assess the progression of chronic periodontitis: a 24-mo prospective multicenter cohort study.

BACKGROUND AND OBJECTIVE: A diagnosis of periodontitis progression is presently limited to clinical parameters such as attachment loss and radiographic imaging. The aim of this multicenter study was to monitor disease progression in patients with chronic periodontitis during a 24-mo follow-up program and to evaluate the amount of bacteria in saliva and corresponding IgG titers in serum for determining the diagnostic usefulness of each in indicating disease progression and stability. MATERIAL AND METHODS: A total of 163 patients with chronic periodontitis who received trimonthly follow-up care were observed for 24 mo. The clinical parameters and salivary content of Porphyromonas gingivalis, Prevotella intermedia and Aggregatibacter actinomycetemcomitans were assessed using the modified Invader PLUS assay, and the corresponding serum IgG titers were measured using ELISA. The changes through 24 mo were analyzed using cut-off values calculated for each factor. One-way ANOVA or Fisher's exact test was used to perform between-group comparison for the data collected. Diagnostic values were calculated using Fisher's exact test. RESULTS: Of the 124 individuals who completed the 24-mo monitoring phase, 62 exhibited periodontitis progression, whereas 62 demonstrated stable disease. Seven patients withdrew because of acute periodontal abscess. The ratio of P. gingivalis to total bacteria and the combination of P. gingivalis counts and IgG titers against P. gingivalis were significantly related to the progression of periodontitis. The combination of P. gingivalis ratio and P. gingivalis IgG titers was significantly associated with the progression of periodontitis (p = 0.001, sensitivity = 0.339, specificity = 0.790). CONCLUSIONS: It is suggested that the combination of P. gingivalis ratio in saliva and serum IgG titers against P. gingivalis may be associated with the progression of periodontitis.

Music before Dental Surgery Suppresses Sympathetic Activity Derived from Preoperative Anxiety: A Randomized Controlled Trial.

The aim of this study was to estimate the relieving effect of music intervention on preoperative anxiety by using heart rate variability (HRV) analysis. In this randomized controlled trial, 86 adult patients were scheduled to undergo impacted tooth extraction under intravenous sedation and local anesthesia and were classified as either fearful or nonfearful based on a questionnaire. Thereafter, the patients were subdivided into 2 groups: those who listened to music from the time that they arrived at the outpatient clinic until immediately before entering the operating room and those who did not listen to music. The effect of music intervention was evaluated by assessing 1) the low-frequency/high-frequency ratio of HRV, in which positive changes indicate increased sympathetic nervous activity, and 2) the coefficient of component variance for high frequency, in which positive changes indicate increased parasympathetic nervous activity, assessed by means of HRV analysis. Subjective preoperative anxiety was evaluated on a visual analog scale. For fearful patients, the mean magnitude of low-frequency/high frequency changes from baseline among those who listened to music was significantly lower as compared with those who did not listen to music (in the private room: -1.45 ± 1.88 vs. 1.05 ± 1.88, P = 0.0096, 95% confidence interval of effect size = -4.52 to -0.48, Cohen's d = -0.75; in the operating waiting room: -2.18 ± 2.39 vs. -0.10 ± 3.37, P = 0.011, 95% confidence interval of effect size = -3.94 to -0.22, Cohen's d = -0.71, respectively). Visual analog scale scores were also significantly different. Coefficient of component variance for high frequency and heart rate did not differ significantly between the 2 groups. From the perspective of autonomic nervous activity, music intervention is useful for relieving anxiety in patients with dental fear before they enter a dental outpatient operating room. Music intervention may relieve anxiety by reducing sympathetic nervous activity, while parasympathetic nervous activity is not involved (UMIN000016882). Knowledge Transfer Statement: The results of this study revealed that music intervention is useful for clinicians when planning preoperative anxiety management of patients with dental fear who undergo impacted tooth extraction under intravenous sedation and local anesthesia. As a bridging intervention, music intervention enables stress management to continue uninterrupted from the patient's arrival at the dental outpatient clinic to intravenous sedation until completion of the dental surgery. With consideration of cost-effectiveness, absence of adverse physical effects, immediate effect, safety in terms of not using drugs, and lack of concerns about recovery, this information could lead to more appropriate decisions regarding anxiety management in dentistry.

Bone augmentation using a highly porous PLGA/ß-TCP scaffold containing fibroblast growth factor-2.

BACKGROUND AND OBJECTIVE: Beta-tricalcium phosphate (ß-TCP), a bio-absorbable ceramic, facilitates bone conductivity. We constructed a highly porous three-dimensional scaffold, using ß-TCP, for bone tissue engineering and coated it with co-poly lactic acid/glycolic acid (PLGA) to improve the mechanical strength and biological performance. The aim of this study was to examine the effect of implantation of the PLGA/ß-TCP scaffold loaded with fibroblast growth factor-2 (FGF-2) on bone augmentation. MATERIAL AND METHODS: The ß-TCP scaffold was fabricated by the replica method using polyurethane foam, then coated with PLGA. The PLGA/ß-TCP scaffold was characterized by scanning electron miscroscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, compressive testing, cell culture and a subcutaneous implant test. Subsequently, a bone-forming test was performed using 52 rats. The ß-TCP scaffold, PLGA-coated scaffold, and ß-TCP and PLGA-coated scaffolds loaded with FGF-2, were implanted into rat cranial bone. Histological observations were made at 10 and 35 d postsurgery. RESULTS: SEM and TEM observations showed a thin PLGA layer on the ß-TCP particles after coating. High porosity (> 90%) of the scaffold was exhibited after PLGA coating, and the compressive strength of the PLGA/ß-TCP scaffold was six-fold greater than that of the noncoated scaffold. Good biocompatibility of the PLGA/ß-TCP scaffold was found in the culture and implant tests. Histological samples obtained following implantation of PLGA/ß-TCP scaffold loaded with FGF-2 showed significant bone augmentation. CONCLUSION: The PLGA coating improved the mechanical strength of ß-TCP scaffolds while maintaining high porosity and tissue compatibility. PLGA/ß-TCP scaffolds, in combination with FGF-2, are bioeffective for bone augmentation.

Toll-like receptor 2-mediated modulation of growth and functions of regulatory T cells by oral streptococci.

This study was designed to determine whether oral streptococci modulate the growth and functions of regulatory T cells. Heat-killed cells of wild-type strains of Streptococcus gordonii and Streptococcus mutans induced the Toll-like receptor 2 (TLR2) -mediated nuclear factor-κB (NF-κB) activation, but their lipoprotein-deficient strains did not. Stimulation with these streptococci resulted in a significant increase in the frequency of CD4(+) CD25(+) Foxp3(+) regulatory T cells in splenocytes derived from both TLR2(+/+) and TLR2(-/-) mice, but the level of increase in TLR2(+/+) splenocytes was stronger than that in TLR2(-/-) splenocytes. Both strains of S. gordonii enhanced the proliferation of CD4(+) CD25(+) Foxp3(+) regulatory T cells isolated from TLR2(+/+) mice at the same level as those from TLR2(-/-) mice in an interleukin-2-independent manner. However, wild-type and lipoprotein-deficient strains of both streptococci did not enhance the suppressive activity of the isolated regulatory T cells in vitro, but rather inhibited it. TLR ligands also inhibited the suppressive activity of the regulatory T cells. Inhibition of the suppressive activity was recovered by the addition of anti-IL-6 antibody. Pretreatment of antigen-presenting cells with the NF-κB inhibitor BAY11-7082 enhanced the suppressive activity of the regulatory T cells. These results suggested that interleukin-6 produced by antigen-presenting cells inhibits the suppressive activity of the regulatory T cells. Wild-type strain, but not lipoprotein-deficient strain, of S. gordonii reduced the frequency of CD4(+)  CD25(+)  Foxp3(+) regulatory T cells in the acute infection model, whereas both strains of S. gordonii increased it in the chronic infection model mice. Hence, this study suggests that oral streptococci are capable of modulating the growth and functions of regulatory T cells in vitro and in vivo.

Application of collagen hydrogel/sponge scaffold facilitates periodontal wound healing in class II furcation defects in beagle dogs.

BACKGROUND AND OBJECTIVE: A three-dimensional scaffold may play an important role in periodontal tissue engineering. We prepared bio-safe collagen hydrogel, which exhibits properties similar to those of native extracellular matrix. The aim of this study was to examine the effect of implantation of collagen hydrogel/sponge scaffold on periodontal wound healing in class II furcation defects in dogs. MATERIAL AND METHODS: The collagen hydrogel/sponge scaffold was prepared by injecting collagen hydrogel, cross-linked to the ascorbate-copper ion system, into a collagen sponge. Class II furcation defects (of 5 mm depth and 3 mm width) were surgically created in beagle dogs. The exposed root surface was planed and demineralized with EDTA. In the experimental group, the defect was filled with collagen hydrogel/sponge scaffold. In the control group, no implantation was performed. Histometric parameters were evaluated 2 and 4 wk after surgery. RESULTS: At 2 wk, the collagen hydrogel/sponge scaffold displayed high biocompatibility and biodegradability with numerous cells infiltrating the scaffold. In the experimental group, reconstruction of alveolar bone and cementum was frequently observed 4 wk after surgery. Periodontal ligament tissue was also re-established between alveolar bone and cementum. Volumes of new bone, new cementum and new periodontal ligament were significantly greater in the experimental group than in the control group. In addition, epithelial down-growth was suppressed by application of collagen hydrogel. CONCLUSION: The collagen hydrogel/sponge scaffold possessed high tissue compatibility and degradability. Implantation of the scaffold facilitated periodontal wound healing in class II furcation defects in beagle dogs.

FGF-2 stimulates periodontal regeneration: results of a multi-center randomized clinical trial.

The efficacy of the local application of recombinant human fibroblast growth factor-2 (FGF-2) in periodontal regeneration has been investigated. In this study, a randomized, double-blind, placebo-controlled clinical trial was conducted in 253 adult patients with periodontitis. Modified Widman periodontal surgery was performed, during which 200 µL of the investigational formulation containing 0% (vehicle alone), 0.2%, 0.3%, or 0.4% FGF-2 was administered to 2- or 3-walled vertical bone defects. Each dose of FGF-2 showed significant superiority over vehicle alone (p < 0.01) for the percentage of bone fill at 36 wks after administration, and the percentage peaked in the 0.3% FGF-2 group. No significant differences among groups were observed in clinical attachment regained, scoring approximately 2 mm. No clinical safety problems, including an abnormal increase in alveolar bone or ankylosis, were identified. These results strongly suggest that topical application of FGF-2 can be efficacious in the regeneration of human periodontal tissue that has been destroyed by periodontitis.

Application of self-efficacy theory in dental clinical practice.

In clinical practice, self-efficacy refers to how certain a patient feels about his or her ability to take the necessary action to improve the indicators and maintenance of health. It is assumed that the prognosis for patient behaviour can be improved by assessing the proficiency of their self-efficacy through providing psychoeducational instructions adapted for individual patients, and promoting behavioural change for self-care. Therefore, accurate assessment of self-efficacy is an important key in daily clinical preventive care. The previous research showed that the self-efficacy scale scores predicted patient behaviour in periodontal patients and mother's behaviour in paediatric dental practice. Self-efficacy belief is constructed from four principal sources of information: enactive mastery experience, vicarious experience, verbal persuasion, and physiological and affective states. Thus, self-efficacy can be enhanced by the intervention exploiting these sources. The previous studies revealed that behavioural interventions to enhance self-efficacy improved oral-care behaviour of patients. Therefore, assessment and enhancement of oral-care specific self-efficacy is important to promote behaviour modification in clinical dental practice. However, more researches are needed to evaluate the suitability of the intervention method.

Root surface conditioning with bone morphogenetic protein-2 facilitates cementum-like tissue deposition in beagle dogs.

BACKGROUND AND OBJECTIVE: Modification of the root surface may play an important role in regenerating the periodontal attachment between the root and periodontal connective tissue. We speculated that bone morphogenetic protein (BMP) application to the root surface constructed a novel attachment by cementum-like hard tissue, although gingival connective tissue proliferated to the root surface. The aim of this study was to examine whether BMP-2 guided cementum-like tissue deposition on a BMP-conditioned root surface. MATERIAL AND METHODS: Root dentin on the buccal side of 24 teeth in four beagle dogs was surgically exposed. The denuded root dentin surfaces were demineralized with EDTA and washed with saline. Subsequently, 15 microL of BMP-2 solution (loading dose, 0.4 and 1.0 microg/microL) was applied to the root dentin surface. In the control roots, phosphate-buffered saline was applied to the root surface. Specimens were analyzed histologically 16 wk after surgery. RESULTS: Formation of cementum-like tissue was frequently observed on the BMP-2-conditioned root at the coronal portion. Cellular cementum-like tissue was separated from the original cementum and encapsulated with gingival connective tissue. Cementum-like tissue formation with BMP-2 at 1.0 microg/microL was significantly greater than that in the control roots and those with BMP-2 at 0.4 microg/microL. Downgrowth of the junctional epithelium in the 1.0 microg/microL BMP-2 group was significantly less than that in the control roots. CONCLUSION: Root dentin surface conditioning with BMP-2 stimulated cementum-like tissue formation and inhibited epithelial downgrowth.

Microbial changes in patients with acute periodontal abscess after treatment detected by PadoTest.

AIMS: To investigate changes in bacterial counts in subgingival plaque from patients with acute periodontal abscess by IAI-PadoTest. MATERIALS AND METHODS: Ninety-one patients were randomly allocated to either test or control groups. In all the patients, pockets with acute periodontal abscess were irrigated with sterilized physiological saline, and in the test group, 2% minocycline hydrochloride ointment was applied once into the pocket in addition. Subgingival plaque samples were collected by paper point before treatment and 7 days after treatment. The total bacterial count was determined and Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, were detected using IAI-PadoTest, a DNA/RNA probe method. RESULTS: The total bacterial count decreased in both groups, with a significant decrease in the test group. The counts and number of sites positive for P. gingivalis, T. forsythia and T. denticola significantly decreased in the test group after treatment, compared with those in the control group. Pocket depth decreased in the both groups, with a statistically significant decrease in the test group. CONCLUSION: Topical treatment with minocycline in pockets with acute periodontal abscess was effective in reducing the bacterial counts as shown by the microbiological investigation using PadoTest 4.5.

Dentin resorption and cementum-like tissue formation by bone morphogenetic protein application.

BACKGROUND AND OBJECTIVE: Recent studies have shown that bone morphogenetic protein-2 (BMP-2) stimulates mineralization and osteoclast differentiation. Osteoclastic resorption by BMP-2 application may play an important role in the regulation of new cementum-like tissue formation on the dentin surfaces. Therefore, this study aimed to examine the effect of BMP-2 application on dentin resorption and cementum-like tissue formation at the dentin surfaces. MATERIAL AND METHODS: Seventy-two flat dentin blocks were prepared from rat roots and treated with 24% EDTA. Each block was assigned to group 0, group 100, or group 400, and immersed correspondingly in 0, 100, or 400 microg/ml BMP-2. The dentin blocks were then implanted into palatal connective tissue of rats, and specimens were prepared 2, 4 and 8 wk after surgery for histologic and histomorphometric analyses. RESULTS: BMP-2 caused a dose-dependent increase in dentin resorption by osteoclastic cells. New cementum-like tissue was randomly formed on parts of the nonresorbed and resorbed dentin surfaces in groups 100 and 400. Dentin resorption in groups 100 and 400 was significantly greater than group 0 (p < 0.01). However, at 8 wk, new cementum-like tissue formed in 41.8% of group 100, as compared with 16.2% of group 400 (p < 0.05). CONCLUSION: Dentin resorption was stimulated by a high dose of BMP-2, and cementum-like tissue was induced by a low dose of BMP-2, effectively suggesting that BMP-2 application, at an appropriate dose, to a dentin surface may enhance periodontal regeneration.

Formation and resolution of ankylosis under application of recombinant human bone morphogenetic protein-2 (rhBMP-2) to class III furcation defects in cats.

OBJECTIVES: Periodontal regeneration under application of bone morphogenetic protein (BMP) is compromised by ankylosis. Ankylosis disappearance following application of BMP has been observed in the case of a small defect, which might be beneficial change for periodontal regeneration. However, the histological observation of ankylosis disappearance has not been demonstrated in a large defect. The purpose of this present study was to confirm resolution of ankylosis during periodontal regeneration by recombinant human BMP-2 (rhBMP-2) applied to class III furcation defects. MATERIAL AND METHODS: Class III furcation defects were created in the premolars of six adult cats. The rhBMP-2 material, prepared by applying rhBMP-2 to a combination of polylactic acid-polygricolic copolymer and gelatin sponge (PGS; 0.33 microg rhBMP-2/mm(3) PGS) or control material containing only PGS, was implanted into each defect. The cats were killed at 3, 6 or 12 weeks after surgery and serial sections were prepared for histological and histometrical observation. RESULTS: Ankylosis was observed in some of the rhBMP-2/PGS group at 3 and 6 weeks, but not at 12 weeks. At 6 weeks, osteoclast-like cells were visible in the rhBMP-2/PGS group with ankylosis. Residual PGS was evident between the bone and root surface in the rhBMP-2/PGS group without ankylosis at 3 weeks. CONCLUSIONS: Resolution of ankylosis by osteoclast-like cells possibly occurred under application of rhBMP-2. Residual PGS might play an important role in preventing ankylosis formation.

Healing in transplanted teeth with periodontal ligament cultured in vitro.

Regeneration of connective tissue attachment is the ultimate goal of periodontal therapy. It has been suggested that periodontal ligament cells possess the potential to create new connective tissue attachment. However, as cells from gingiva and alveolar bone occupy the root surface during initial wound healing, population by periodontal ligament cells is limited in vivo. We have been developing a new periodontal regeneration technique using in vitro tissue culture of periodontal ligament remaining on a periodontally involved root. The purpose of this study was to examine the periodontal healing after transplantation of teeth with reduced periodontal ligament that had been cultured in vitro. Twenty-five incisors from four beagles were used. After the teeth were extracted, the periodontal ligament and cementum were removed from coronal part of the roots and the roots were planed. The periodontal ligament of the apical part was retained. Fourteen teeth of the experimental group were transplanted following culture for 6 weeks. Eleven teeth of the control group were similarly prepared and immediately transplanted without tissue culture. Four weeks after transplantation, the specimens were prepared for histological analysis. Downgrowth of junctional epithelium on the root of experimental group was significantly less than control. Most of the root planed surfaces of experimental group were covered with periodontal ligament fibers oriented parallel or inclined to the root surfaces and limited new cementum formation was observed near the apical end of the planed root. There was no significant difference between groups in observations on the root surface with remaining periodontal ligament. From the above results, it was concluded that periodontal tissue culture of teeth with root planed surface and remaining periodontal ligament could reduce the extent of epithelium downgrowth and increase connective tissue adhesion on the root planed surface, as well as minimize damage to remaining periodontal ligament, after transplantation of teeth.

Periodontal healing after bonding treatment of vertical root fracture.

Vertical root fractures lead to advanced periodontal breakdown with deep periodontal pockets and vertical bone defects. The purpose of this study is to evaluate clinically the periodontal healing of root fracture treatment using adhesive resin cement. In 22 patients, 23 teeth with vertical root fractures were treated with 4-META/MMA-TBB resin cement. Eleven fractured roots were bonded through the root canal (group A) and 12 fractured roots were bonded extra-orally and replanted (group B). All teeth were then restored with full cast crowns (n=20) or coping (n=3). Mean probing depth was 6.6 mm at pre-treatment and 4.4 mm 6 months after the treatment in group A, and 7.4 mm and 4.6 mm, respectively, in group B. Bleeding scores were 100% at pre-treatment and 36.4% after 6 months in group A and 91.7% and 8.3%, respectively in group B. Radiographic bone level was 56.8% at pretreatment and 59.1% after 6 months in group A, and 18.8% and 29.2%, respectively, in group B. Two roots of group A and three roots of group B were extracted due to refracture, deterioration of periodontal inflammation, mobility, and luxation. The remaining roots (n=18) presented no discomfort to the patients and there was no deterioration of periodontal conditions over a mean period of 33 months (range 14-74 months) in group A and over a mean period of 22 months (range 6-48 months) in group B. There was no ankylosed teeth nor was any root resorption detected. The results suggested that the treatment of vertical root fracture using 4-META/MMA-TBB resin has good prognostic possibilities.

Churg-Strauss syndrome with pachymeningitis refractory to steroid therapy atone--a case report.

Churg-Strauss syndrome (CSS) is a rare syndrome of unknown cause, which is characterized by bronchial asthma and hypereosinophilia followed by systemic symptoms of angiitis. In 1951, Churg and Strauss first distinguished this disease from periarteritis nodosa. Our patient in particular was also complicated with otorhinological symptoms, which have less frequently been reported in CSS cases. We have detailed her clinical symptoms.

Periodontal healing after replantation of intentionally rotated teeth with healthy and denuded root surfaces.

The purpose of the study was to evaluate periodontal healing after replantation of intentionally rotated teeth with healthy and denuded root surfaces. Ten teeth with hopeless prognoses because of extensive alveolar bone loss and deep pockets extending to the apexes only on one or two surfaces, but with a healthy periodontal apparatus on the other surfaces, were selected. A mucogingival flap was elevated and the teeth were extracted carefully so as not to damage the healthy remnant of the periodontal membrane remaining on the root surfaces. Thorough extra-oral debridement was performed on the contaminated root surface and the remnant was carefully conserved. Retrofilling was also done to eliminate an endodontic cause of attachment loss. The teeth were horizontally rotated and then replanted so that the healthy root would face the connective tissue at the initially periodontally involved sites, and the root planed surfaces, which had been periodontally involved, would face the surfaces of the alveolar sockets at initially healthy sites. The teeth were splinted with adjacent teeth. Clinical parameters and radiographic examination were performed pre-operatively, and at 3 or 6 months, 1, 2, and 3 years postoperatively. One tooth was extracted 1.5 years postoperatively due to reduced support and the treatment strategy of the patient. The other nine teeth were well maintained without any discomfort for the whole maintenance period of 3 years. In all teeth, areas that previously had no pocketing but were now against denuded root surfaces maintained the previous pocket depth readings. In areas where a deep pocket was present but now had a root surface with healthy periodontium, a distinct decrease of mean pocket depth was observed at the first reexamination 3 months postoperatively. The mean radiographic alveolar bone level increased from 0.3% to 45.3% in 2 years and was thereafter maintained for the entire observation period. Loss of periodontal space and possible root resorption were observed in only one case without other ankylotic symptoms. These results suggest that the healing without ankylosis of an extensive denuded root surface may occur by mechanisms other than the maintenance of a viable periodontal ligament on the root surface.

Effect of aging on bone formation induced by recombinant human bone morphogenetic protein-2 combined with fibrous collagen membranes at subperiosteal sites.

This study was designed to examine the effect of aging on bone formation induced by recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with a fibrous collagen membrane (FCM). Implantation was done subperiosteally in bilateral palatal grooves in 34 male Wistar rats divided into three age groups: a 10-week-old group (10w group), a 30-week-old group (30w group) and a 70-week-old group (70w group). RhBMP-2-combined FCMs were implanted on the left palatal grooves as BMP-implanted sites (BMP site), while rhBMP-2 was not implanted on the right palatal grooves as control sites. The rats were sacrificed 6 weeks after implantation, and histometric evaluations were performed. New bone formation was observed in every site of each age group and the new bone was almost completely continuous with the original bone. The new bone volume (NBV) of the BMP site was significantly higher than that of the control site in each age group. The NBV of both the control and BMP sites were highest in the 10w group and lowest in the 70w group. The disparity of NBV between the control and BMP sites, which indicated the response to implanted BMP excluding the effect of skeletal growth and surgical stimulation, did not significantly differ among the age groups. These results indicate that rhBMP-2-combined FCM has the ability to induce new bone formation continuous with original bone even in senescent rats. Furthermore, it appeared that, in the case of palatal subperiosteal implantation, the responsiveness to implanted BMP was independent of age, although the total volume of newly formed bone declined with aging.

Microscopic polyangiitis that presented liver dysfunction prior to noted renal manifestations.

In microscopic polyangiitis (MPA), renal manifestations are very common as first symptoms. Here, we report a case of MPA which presented liver dysfunction prior to noted renal manifestations. A 58-year-old woman was hospitalized because of a fever for 8 weeks. A laboratory examination revealed marked elevation of alkaline phosphatase and gamma-glutamyl transpeptidase, while blood urea nitrogen and creatinine levels remained normal. Although apparent renal dysfunction developed in this case soon after hospitalization, physicians should be aware of the variety of clinical manifestations in MPA. Moreover, antineutrophil cytoplasmic autoantibodies were found to be helpful for diagnosing MPA.

Infraposition of ankylosed permanent maxillary incisors after replantation related to age and sex.

The extent of infraposition of replanted and subsequently ankylosed permanent incisors was examined in a longitudinal study of 52 patients. Study cast models were made during the follow-up period. Infraposition was evaluated on frontal photos of the study cast models taken parallel with the occlusal plane. The extent of infraposition was defined as the difference between the position of the incisal edge of the replanted incisor and the adjacent non-injured incisor in apico-coronal direction, measured with a digital caliper at 50x magnification of the negatives. The precision of this measuring procedure was 2.9% and the accuracy 2.0%. Marked infraposition was identified if the tooth was traumatized before the age of 16 in boys and before the age of 14 in girls. In addition, infraposition was observed when ankylosis developed in patients aged 20-30 years, with a yearly mean infraposition rate of 0.07 mm/year (range: 0.02-0.21 mm/year) in males and 0.07 mm/year (range: 0.00-0.12 mm/year) in females. The latter findings supported the concept of slow continuous eruption of the teeth. This phenomenon may have implications not only for the treatment of traumatized teeth but also for the treatment of tooth loss by osseointegrated implants, which represent an analogue to the ankylosed replanted tooth.