Histologic observations of periodontal wound healing after treatment with PerioGlas in nonhuman primates

The effect of PerioGlas (synthetic bone particulate) on wound healing of experimental palatal periodontal defects in monkeys was evaluated. Chronic periodontal defects were created on the palatal aspects of maxillary molars and premolars. Open-flap debridement was performed. Experimental sites received PerioGlas, while control sites received no further treatment. Histologic measurements were performed on new bone, new cementum, epithelial downgrowth, and recession. Results showed significantly more new cementum and less epithelial downgrowth in the sites that received PerioGlas (P < 0.05). The present results indicate that PerioGlas may enhance periodontal wound healing outcomes.     

Microbial factors and gingival crevicular fluid aspartate aminotransferase levels

Abstract. The aim of this cross-sectional study was to investigate the clinical application of chairside tests for gingival crevicular fluid (GCF) aspartale amino-transferase (AST) levels and plaque BANA hydrolysis activity with the presence of the periodontal pathogens Porphyromonas gingivalis and Actinohacillus action-mycetemcomitans. The study comprised 100 periodontitis sites (pocket depths≥4 mm. GI = 3) from 10 patients with chronic adult periodontitis and 100 control sites (pocket depths <4 mm. GI<3) from 10 periodontally healthy patients comprising 55 healthy sites (pocket depths <4 mm. GI=0) and 45 gingivitis sites (pocket depths <4 mm, GI=1 or 2). The values for both BANA hydrolysis and AST levels were significantly higher in samples from periodontitis compared with gingivitis and healthy sites (p<0.001), A. actinomycetemcomitans was identified in 45% and P. gingivalis in 17% of periodontitis sites but neither pathogen was recovered from control sites and there was no significant correlation with (he clinical parameters measured. There was no significant relationship between the presence of P. gingivalis and/or A. actinmycetemcomitans with BANA hydrolysis or AST levels. A significant correlation (p=0.0017) was observed between BANA hydrolysis and pocket depth and between AST hydrolysis and the GI (p=0.01). This study failed to demonstrate a positive association between chairside analysis of GCF metabolites for AST levels and/or BANA hydrolysis with P. gingivalis and A. actinomycetemcomitans. However, the GCF metabolites had a significant correlation with periodontally diseased sites in patients with chronic adult periodontitis and may help confirm clinical observations.     

Extended bleaching of tetracycline-stained teeth: a 5-year study

Bleaching tetracycline-stained teeth is the most challenging form of tooth lightening. This article reports on 44 subjects who bleached their tetracycline-stained teeth for 6 months using trays with reservoirs overnight in a half-mouth designed study and 2 of 3 different concentrations of carbamide peroxide (10%, 15% or 20%). The subjects were followed for 5 years. The area evaluated was the middle third of the teeth. More than 55% of tooth lightening occurred within 1 month; after 5 years, more than 65% of the maximum tooth whitening remained for all 3 gel concentrations. Tooth whitening can be accomplished with any of the 3 concentrations used.     

Microhardness evaluation of in situ vital bleaching on human dental enamel using a novel study design.

OBJECTIVES: The aim of this 'in situ' study was to evaluate the microhardness of dental enamel following treatment with an in-office and an at-home vital bleaching agent through a novel approach using samples temporarily bonded 'in vivo'. METHODS: Human dental enamel slabs (n=88) were subjected to sequential polishing and initial Knoop microhardness tests were performed. The slabs were fixed to the facial surfaces of the maxillary first molars of 44 human volunteers. They were divided into four groups (n=11) according to the treatment group: G1- in-office-CP37+ at-home-CP10; G2- in-office-CP37+ at-home-PLA; G3- in-office-PLA and at-home-CP10; G4- in-office and at-home-PLA. After 3 weeks of treatment, final microhardness measurements were performed. RESULTS AND SIGNIFICANCE: ANOVA and Tukey's HSD hoc analysis (alpha=0.05) revealed no differences among initial or final microhardness values (p>0.05); however, significant differences occurred between initial and final values for each group (p<0.01), The evaluation of microhardness revealed a reduction of 6.8% for G1, 4.1% for G2, 3.4% for G3 and 3.5% for G4. In-office bleaching with 37% carbamide peroxide, an at-home bleaching with 10% carbamide peroxide, and a combination of both resulted in lower enamel microhardness when measured immediately post-treatment. However, long-term effects of these treatments are not known, and are believed to be clinically insignificant due to the relatively small reductions observed in enamel microhardness. Interestingly, the carrier, Cabopol 934P, also resulted in similar reduction in enamel microhardness even when administrated alone as a placebo.     

The effect of one session of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis

Supragingival plaque control is a requisite for the success of any periodontal procedure. However, little is know about the effect of this procedure alone on periodontitis. The aim of this study was to determine the effect of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis. Twenty-five subjects exhibiting at least 4 pockets > 5mm, non-smokers and with no relevant systemic diseases, were selected for the study. The clinical and biochemical assessments were done before and 21 days after removal of plaque retentive factors, extraction of affected teeth and instruction in oral hygiene. The statistical analysis was done with the Student paired t-test (p<0,05) and demonstrated a reduction on the percentage of sites with bleeding on probing from 42.72 ± 15.83 to 35.87 ± 13.30 (p=0.002). Reduction in probing depth was detected on anterior teeth (initial/final mean: 2.88 mm/2.78 mm; p=0.01) and interproximal sites (initial/final mean: 3.80 mm/3.65 mm; p=0.001). There was an increase from 66.81% to 68.65% in the number of sites with probing depth of 1 to 3mm and a decrease from 26.21% to 24.17% in those with probing depth of 4 to 6mm. The BAPNA results showed a decrease from 51.44 ± 20.78 to 38.64 ± 12.34 (p=0.04). This study demonstrated that supragingival plaque control provides a reduction in gingival inflammation and alterations in the subgingival microflora detected by the BAPNA test.     

Craniofacial morphology and inclination of the posterior slope of the articular eminence in female patients with and without condylar bone change

This study investigated the association of craniofacial and glenoid fossa shapes and temporomandibular joint (TMJ) pathology in 39 orthodontic patients with signs and symptoms of TMJ disorders, using helical CT scans. Cephalometric measurements showed that 21 subjects with bilateral condylar bone change (BBC) had significantly smaller SNB angles, ramus heights and S-Ar/N-Ba ratios, as well as larger mandibular plane angles and lower anterior facial height than the 18 subjects with no condylar bone change (NBC). The average posterior slope of the left and right articular eminence in their central and lateral sections was significantly steeper in NBC than in BBC. Condylar bone change might, therefore, not only be related to the morphology of the mandible, but also of the glenoid fossa and cranial base. This appears to reflect adaptive changes in the condyle, articular eminence and cranial base in response to changes in loading.     

Locally produced anti-phosphorylcholine and anti-oxidized low-density lipoprotein antibodies in gingival crevicular fluid from aggressive periodontitis patients

BACKGROUND: Sera from patients with periodontal attachment loss contain higher concentrations of IgG anti-phosphorylcholine (anti-PC) than sera from healthy subjects. Furthermore, a large proportion of plaque bacteria bear PC-containing surface antigens, implicating the oral flora as a source of immunogen for anti-PC. Additionally, anti-PC is cross-reactive with a variety of oral bacterial antigens and human antigens such as oxidized low-density lipoprotein (oxLDL). We hypothesized that, if the oral flora is a source of PC antigens, then we should be able to detect local anti-PC and anti-oxLDL production in gingival crevicular fluid (GCF). METHODS: To test this, we collected 66 GCF samples from 15 patients with aggressive periodontitis and examined both the GCF samples and serum samples for their content of IgG anti-PC, IgG anti-LDL, and IgG anti-oxLDL by enzyme-linked immunosorbent assay. We also determined levels of anti-tetanus toxoid (anti-TT) as a non-oral antigen control. Serum and GCF concentrations of serum albumin (HSA) were also determined for use as a dilution marker. A conservative GCF:serum antibody ratio of greater than 1.5 was considered to be evidence of local antibody production. RESULTS: For the non-oral antigen TT, only one out of 62 samples contained locally produced antibody. Eight out of 64 samples (7 from a single subject) demonstrated local production of anti-LDL. In contrast, 28 out of 66 samples demonstrated local production of anti-PC, and 47 out of 66 samples contained locally produced anti-oxLDL. It was observed that A. actinomycetemcomitans strains containing or devoid of PC could absorb anti-oxLDL from human sera. Although there was a correlation between the ratios of anti-PC and anti-oxLDL (Spearman's rho = 0.35, P = 0.0037), local production of both antibodies was found in only 17 out of 65 samples, indicating that these antibodies are not always reflective of reactivity to the same antigens. CONCLUSION: The local production of anti-PC and anti-oxLDL further implicates the oral flora as a source of antigen that may mediate immune reactions of relevance to cardiovascular and other systemic diseases.     

Human periodontal ligament cell responses to recombinant human bone morphogenetic protein-2 with and without bone allografts

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been found to promote the osteoblastic differentiation of human periodontal ligament cells. Its effect depends on the delivery system used. In this study we examined the effect of rhBMP-2 on the proliferation and osteoblastic differentiation of human periodontal ligament cells cultured alone or with 3 different bone allografts. METHODS: The rhBMP-2 effect on cell proliferation and osteoblastic differentiation was examined by measuring [3H] thymidine incorporation and ALPase activity, respectively, on human periodontal ligament (hPDL) cells. Two human demineralized freeze-dried allografts of cortical (DFDBAco) and cancellous (DFBDAca) bone origin and 1 non-demineralized freeze-dried allograft (FDBA) of cancellous bone origin, derived from different tissue banks, were used to evaluate the rhBMP-2 effect on cell osteoblastic differentiation. The measurements were taken on various days. RESULTS: rhBMP-2 decreased hPDL cell proliferation. rhBMP-2 acted on the third day of the process of cell differentiation, had a specific time of action, achieved its peak effect on the fourth and fifth days, and then did not provoke any further effects. The 3 bone allografts were efficiently combined with rhBMP-2. The combination of rhBMP-2 and DFDBAco showed the effect with the longest duration. rhBMP-2, on day 4, made the inactive bone allograft more active while, on the other days, its effect was dependent on the allograft alone. CONCLUSIONS: rhBMP-2 promotes the osteoblastic differentiation of human periodontal ligament cells and decreases cell proliferation. In this study rhBMP-2 in the presence of the bone allografts tested resulted in hPDL cell differentiation.     

Periodontal conditions in patients with juvenile idiopathic arthritis

OBJECTIVE: Our aim was to compare the periodontal conditions in a group of juvenile idiopathic arthritis (JIA) patients with those in a control group of healthy subjects (CTR). MATERIAL AND METHODS: Thirty-two patients with JIA and 24 controls were selected. The measurements used to diagnose periodontal disease included plaque and bleeding scores, probing depths (PDs) and clinical attachment loss (CAL). Laboratory indicators of JIA activity included the erythrocyte sedimentation rate (ESR) and capsule-reactive protein (CRP). The Mann-Whitney test was used to evaluate the data (alpha = 0.05). RESULTS: The mean ages were 15.9 (+/- 2.7) years and 14.7 (+/- 2.3) years for groups JIA and CTR, respectively. The median ESR was 42 mm/h 13 mm/h in the CTR group (p = 0.032) and the median CRP was 1.9 and 0.4 mg/l, respectively (p = 0.001). The prevalence of patients with a proximal attachment loss of 2mm or more in the JIA group was 25% and in controls it was 4.2%. The mean percentages of visible plaque and marginal bleeding were similar in the JIA (54 +/- 22 and 30 +/- 16, respectively) and CTR groups (44 +/- 18 and 29 +/- 11, respectively). The mean percentages of sites with PD > or = 4 mm were significantly higher in the JIA group (3 +/- 4.7) than in the CTR group (0.4 +/- 1.7) (p = 0.012). The mean percentages of sites with proximal CAL > or = 2 mm were 0.7 (+/- 1.4) in the JIA group and 0.001 (+/- 0.2) in the CTR group (p = 0.022). CONCLUSION: Adolescents with JIA present more periodontal attachment loss than healthy controls, in spite of similar plaque and marginal bleeding levels.     

In-use peroxide kinetics of 10% hydrogen peroxide whitening strips

OBJECTIVE: Clinical research was conducted to establish the peroxide degradation profile of a very thin 10% hydrogen peroxide bleaching gel delivered on a flexible polyethylene strip. METHODS: Sixteen subjects participated in this study of Crest Whitestrips Premium, a thin layer of 10% hydrogen peroxide gel. Application was supervised, and strips were removed after five, 10, 30, and 60 minutes. Samples were collected from the strips, teeth, gingiva, and saliva, and peroxide levels were derived using a colorimetric peroxide assay. RESULTS: At five minutes, median peroxide concentrations were 7.3%, 6.4%, and 0.7% for strips, teeth, and gingiva, respectively, declining to 4.6%, 2.9%, and 0.1% at 30 minutes. Salivary samples never exceeded a median concentration of 0.014% at any time point. Samples differed significantly (p < 0.01) with respect to the 30- and 60-minute area-under-the-curve calculations, with the highest concentrations on the strip and teeth, and the lowest on the gingiva and in saliva. Median peroxide concentrations on strips and teeth remained above 2% over 60 minutes. At all post-treatment time points, the gingival peroxide concentration was an order of magnitude lower than the teeth samples. CONCLUSION: Use of 10% hydrogen peroxide whitening strips yielded appreciable peroxide on teeth over a 60-minute period, with rapid peroxide degradation on the gingiva, and exceedingly low accumulation in saliva anytime during use.