Periodontal pathogen detection in gingiva/tooth and tongue flora samples from 18‐ to 48‐month‐old children and periodontal status of their mothers

Few studies have detected periodontal pathogens in young children, and when detected the prevalence has been relatively low. In this epidemiological study, we determined the prevalence of periodontal pathogen colonization in young children and examined the relationship between periodontitis in mothers and detection of periodontal pathogens in their children aged 18–48 months. Children were selected and enrolled randomly into the study; tongue and gingival/tooth plaque samples were harvested and analyzed by DNA probe checkerboard assay for Porphyromonas gingivalis and Bacteroides forsythus. Clinical measurements included a gingival bleeding score in the children and a periodontal screening and recording (PSR) score in the mothers. Mothers having one or more periodontal sites with probing depths > 5.5 mm were classified as having periodontitis. In this population, 71% (66/93) of the 18‐ to 48‐month‐old children were infected with at least one periodontal pathogen. Detection rates for children were 68.8% for P. gingivalis and 29.0% for B. forsythus. About 13.8% (11/80) of children had gingival bleeding in response to a toothpick inserted interproximally. Children in whom B. forsythus was detected were about 6 times more likely to have gingival bleeding than other children. There was no relationship between bleeding and detection of P. gingivalis. 17.0% (16/94) of the mothers had periodontitis. When all mother–child pairs were considered, the periodontal status of the mother was found not to be a determinant for detection of periodontal pathogens in the floral samples from the children. However, the odds ratio that a daughter of a mother with periodontitis would be colonized was 5.2 for B. forsythus. A much higher proportion of children in this population were colonized by P. gingivalis and/or B. forsythus than has been previously reported for other populations. A modest level of association between manifestations of periodontitis in mothers and detection of B. forsythus in their daughters was observed.     

T‐cell independent production of salivary secretory IgA after hematopoietic stem cell transplantation in children

This study examined the recovery of secretory IgA (S‐IgA) in saliva after hematopoietic stem cell transplantation (HSCT) in 35 children and young people between the ages of 3 and 27 years (mean = 13.6), and compared this recovery with that of serum immunologic constituents. Reference values for human salivary S‐IgA in saliva were obtained from 77 healthy control subjects between the ages of 7 and 25 years (mean = 11.4). In the 35 patients, a nadir of secretory IgA concentrations in saliva (S‐IgA) was observed between the 3rd and the 4th month, and a return to normal values 1 year after HSCT. Serum IgA concentrations reached their nadir in the 6th month, and normalized in the 18 months after HSCT. The recovery of T‐helper cells (CD4⁺/3⁺) was also delayed to beyond 18 months. We found a significant correlation between the reconstitution pattern of S‐IgA and that of T‐helper lymphocytes, but no correlation was found between the post‐transplant evolutions of S‐IgA and serum IgA, or between S‐IgA and T‐helper cells. The recovery of S‐IgA was more rapid than that of serum IgA and appeared to be T‐helper cell independent.     

Correlations between cephalic posture and facial type in patients suffering from breathing obstructive syndrome.

AIM: In this teleradiographic study, the authors investigate the correlations between facial kind, breathing pattern and cephalic posture. METHODS The research was conducted on a 94 schoolchildren sample. For each patient teleradiographic analysis in-L-L projection and rhinomanometric examination were performed. On the basis of clinical evidences, rhinomanometric results and nasopharyngeal space evaluation, the sample was divided into two groups: the first one included 36 oral breather patients (OB), the second one 58 nasal breathers (NB). RESULTS: The two groups do not differ significantly, with the exception of divergence values, frequently higher in OB than NB. The comparison of craniofacial features and cephalic posture among the groups points out to correlations between large craniocervical angle and skeletal Class II, mandibular retrognathia and increased gonial angle, respectively, not related to breathing patterns. CONCLUSION: According to the authors' results, it can be stated that morphological characteristics classically associated with breathing obstructive syndrome could be induced by altered cephalic posture instead.     

The effect of casting procedures on rotational misfit in castable abutments

PURPOSE: Misfit of implant components has been linked to restorative complications such as screw loosening. Although previous studies have shown a correlation between rotational misfit and screw loosening, the impact of casting procedures on rotational misfit is lacking. The aim of this in vitro study was to evaluate the effect of casting procedures on rotational misfit of cast abutments when compared to machined titanium abutments. MATERIALS AND METHODS: Forty-eight external hexagonal implants and 48 abutments were placed in 4 groups of 12 samples each: (1) machined titanium abutments, (2) premachined palladium abutments cast-on with palladium, (3) plastic burnout abutments cast with nickel chromium, and (4) plastic burnout abutments cast with cobalt chromium. Rotational misfit between the external hexagon of the implant and the internal hexagon of the abutment was measured using standardized techniques and recorded in degrees. Mean values for each group were analyzed with analysis of variance and Tukey test. RESULTS: The mean rotational misfit was 1.21 +/- 0.57 degrees for machined titanium abutments, 1.77 +/- 130 degrees for cast-on abutments, 1.98 +/- 0.72 degrees for cast NiCr abutments, and 2.79 +/- 1.13 degrees for cast CoCr abutments. Significantly greater rotational misfit was recorded with cast CoCr abutments when compared to machined titanium abutments (P < .05). CONCLUSION: Rotational misfit was less than 2 degrees for all groups except for cast CoCr abutments, which demonstrated a significantly greater rotational misfit.     

Metabolism of vitamin E acetate by reconstituted human gingival and buccal epithelium

Aim : To demonstrate metabolism of vitamin E acetate to vitamin E by human gingival and buccal reconstituted epithelial cell cultures. Method : Human gingival and buccal reconstituted epithelial cell cultures (SkinEthic, France) were exposed to vitamin E acetate and maintained for up to seven days at 37°C (5% CO₂) in a humidified incubator. Following organic extraction of the cultures, reverse phase HPLC was used to analyse the quantities of vitamin E and vitamin E acetate in the cultures. Results : The ratio of vitamin E to vitamin E acetate increased up to 30 fold more than the solution control in gingival cultures after 7 days. Conclusion : This paper demonstrates that human gingival and buccal epithelial cells can metabolise vitamin E acetate to vitamin E, thus delivering the more active vitamin E species under the control of the activity of endogenous host enzymes.     

The effect of ketoprofen creams on periodontal disease in rhesus monkeys

Ketoprofen creams were evaluated for the treatment of periodontal disease in a placebo-controlled, double-blind study in the rhesus monkeys, Macaca mulatta. Two formulations containing ketoprofen (1%), with or without vitamin E, were evaluated against appropriate controls (8 monkeys per group). Two weeks prior to treatment, the animals received prophylaxis on only the left side of the mouth (spontaneous model). Selected teeth on the right side of the mouth were ligated (ligature model). The creams were administered to the gingiva once daily at a standard dose of 1.8 ml per monkey for 6 months. Clinical assessments were made 2 wk before initiation, at baseline and 1, 2, 3 and 6 months post-treatment. The clinical parameters included plaque formation, gingival redness, edema, bleeding on probing and Ramfjord Attachment Level measurements (RAL). Radiographs were taken at 2 wk before initiation, baseline and at 3 and 6 months post-treatment. Digital subtraction radiography was used to measure vertical linear bone loss along the interproximal root surfaces of the left and right mandibular first molars. Gingival crevicular fluid (GCF) was collected for biochemical assays on PGE₂, TxB₂, LTB₄, IL-1β and TNFα. There were no significant differences among groups with respect to gingival indices. Radiographic data demonstrated significant positive effects on bone activity in both groups treated with ketoprofen formulations with improvement over time in the ligature model (0.01 ≤p≤ 0.04). The placebo group exhibited bone loss of 1.96±0.48 and 1.40±0.56 mm per site at 3 and 6 months, respectively. The group treated with ketoprofen cream showed an apparent bone gain of 0.28±0.41 and 0.78±0.47 mm per site at 3 and 6 months, respectively. The group treated with ketoprofen cream containing vitamin E showed a mean bone loss of 0.41–0.48 mm per site at 3 months with improvement to an apparent bone gain of 0.31±0.44 mm per site at 6 months. The biochemical data demonstrated early and significant suppression of GCF-LTB₄ by both ketoprofen formulations at 1 month, which preceded the significant suppression of GCF-PGE₂ at 2 and 3 months in the ligature model (p≤0.003) and at 2 to 6 months in the spontaneous model (p≤0.02). We conclude that ketoprofen at 1% level in suitable topical vehicles can effectively inhibit GCF-LTB₄ and GCF-PGE₂ and positively alter alveolar bone activity in the ligature-induced model of periodontitis in the monkey.     

Measurement of proteases in human subgingival dental plaque by fluorescence polarization

Fluorescence polarization (FP) was examined as a rapid quantitative method to assay the proteases in subgingival plaque. Protease activity was measured by a decrease in FP at 0.5-min intervals over 5 min, using BODIPY®--casein, a protein substrate. To quantitate activity, the least absolute deviation (LAD) slope for each assay was determined. Protease activity increased with the quantity of plaque (r=0.416, P<0.001). Of the 208 subgingival plaque samples, 87 contained detectable protease activity, with a mean of about 4 μg trypsin equivalents above a general background of 1 μg per site. The mean plaque protease activity of 89 paired samples from 15 individuals had decreased by 1.1 μg trypsin equivalents per site when measured at 8 months after tooth scaling and root planing (P<0.01). Most isolates of Porphyromonas gingivalis, Treponema denticola, Prevotella nigrescens, and Prevotella intermedia implicated in the pathogenesis of adult periodontitis exhibited high activity in the FP assay. The assay is rapid, quantitative and requires only one-tenth of the plaque sampled using a single pass with a Gracey curette at a single tooth site.     

The influence of bone mechanical properties and implant fixation upon bone loading around oral implants.

Finite element models were created to study the stress and strain distribution around a solitary BAnemark implant. The influence of a number of clinically relevant parameters was examined: bone-implant interface (fixed bond versus frictionless free contact), bone elastic properties, unicortical versus bicortical implant fixation and the presence of a lamina dura. Bone loading patterns in the vicinity of the implant seem to be very sensitive to these parameters. Hence they should be integrated correctly in numerical models of in vivo behaviour of oral implants. This necessitates the creation of patient-dependent finite element models.