Initial subgingival colonization of 'pristine' pockets

The treatment of periodontitis/peri-implantitis involves the reduction/eradication of periopathogens. After therapy, beneficial and pathogenic species recolonize the subgingival area. The dynamics of recolonization and especially the role of the supragingival environment in this process are still not well-understood. This prospective, split-mouth study followed the early colonization of 'pristine' pockets created during implant surgery (16 partially edentulous patients), to record the time needed before a complex subgingival flora could be established with the supragingival area as the single source. Four subgingival plaque samples were taken from shallow and medium pockets around implants (test), and neighboring teeth (undisturbed microbiota as reference) 1, 2, and 4 wks after abutment connection. Checkerboard DNA-DNA hybridization and culture data revealed a complex microbiota (including several pathogenic species) in the pristine pockets within a wk, with a minimal increase in counts up to 4 wks. Analysis of these data demonstrated that, even with the supragingival environment as the single source for colonizing bacteria, a complex subgingival microbiota can develop within 1 wk.     

The relation between the point of force application and flaring of the anterior segment

The purpose of this study was to determine whether application of an intrusive force by an intrusion arch at the distal wings of the lateral incisor brackets causes a change in the axial inclination of the anterior segment. Maxillary incisor intrusion was performed, and records were taken from 40 adolescent patients at the beginning and end of intrusion. Intrusion of the maxillary anterior segment caused a statistically significant mean increase in axial inclination of the central incisor of 8.74 degrees. The following correlations were investigated and found not statistically significant. The correlation between the (1) distance from the point of force application to the center of resistance at the start of intrusion and the change in axial inclination of the incisor, (2) distance from the point of force application to the center of resistance at the start of intrusion and the change in distance from the incisal edge to the distal side of the first molar, (3) distance from the point of intrusive force application to the center of resistance at the start of intrusion and at the end of intrusion, (4) distance from the point of intrusive force application to the center of resistance at the start of intrusion and the change in this distance between start and end of intrusion, and (5) amount of intrusion and the change in axial inclination.     

Comparison of the bleeding on marginal probing index and the Eastman interdental bleeding index as indicators of gingivitis

AIM: The purpose of the present study was to compare 2 indices, i.e., the Eastman interdental bleeding (EIB) index and the bleeding on marginal probing (BOMP) index. The comparison was made (a) in terms of the degree of bleeding provoked and the relationship with plaque in natural gingivitis and (b) for the ability of these 2 methods to detect differences between the development of experimental gingivitis in a control group and a group in which the development of gingival inflammation was suppressed by treatment. For the present studies, subjects were selected without interdental recession of the gingival tissues. METHODS EXPERIMENT 1: In this experiment, 43 subjects having established moderate gingivitis were assessed using a random splitmouth design (1st and 3rd/2nd and 4th quadrant). Plaque was scored on all approximal sites after which the BOMP index was assessed in one half of the mouth and the EIB index in the other. RESULTS EXPERIMENT 1: The BOMP index showed a bleeding score of 84% and the EIB index of 87%. The significant correlation between plaque and gingival bleeding for the BOMP index (0.55) was higher than for the EIB index (0.44). METHODS EXPERIMENT 2: For this experiment, 25 subjects participated in an experimental gingivitis trial of the lower jaw. At baseline, first the BOMP index and immediately thereafter the EIB index were assessed at all approximal sites. Experimental gingivitis (EG) was carried out in one randomly assigned quadrant and as a treatment modality only floss was used in the other (FL). RESULTS EXPERIMENT 2: In the EG quadrant, the BOMP index increased to 69% and the EIB index to 73%. Both indices showed a significant correlation with plaque; 0.60 and 0.64 respectively. In the FL quadrant, the BOMP index increased to 38% and the EIB index to 30%. No significant correlation between both gingivitis indices and the amount of plaque was present in the FL quadrant. CONCLUSION: The ability of the BOMP index and the EIB index to assess the level gingival inflammation appears to be comparable.     

CAD/CAM-copings for partial coverage

Aim of the study was to evaluate the Computer Integrated Ceramic Reconstruction (CICERO)-system and the Ceramic Reconstruction (CEREC)-system for the production of all ceramic copings for partial coverage. Posterior teeth were prepared and the stone dies were made. Accuracy analyses were performed on ceramic restorations made by means of the CICERO and by means of the CEREC technique. The marginal gaps were compared to that of a control cast metal restoration. The results demonstrate that the marginal gaps of the CICERO and CEREC copings varied respectively for the premolar 58-80 microns (mean 69 microns) and 71-91 microns (mean 81 microns). For the upper molar 63-92 microns (mean 78 microns) and 68-110 microns (mean 89 microns) and for the lower molar 54-98 microns (mean 76 microns) and 73-99 microns (mean 86 microns). Control cast metal partial coverage restorations showed marginal gaps of 33, 49 and 41 microns. It is concluded that computers can produce copings for partial coverage preparations on stone dies with a mean marginal gap for CICERO copings of 74 microns and for CEREC copings of 85 microns. These values were obtained before optimizing the marginal fit by means of porcelain veneering.     

Sjögren's syndrome. Consequences for oral health

Sj?gren's syndrome is an auto-immune disease involving exocrine glands causing amongst others xerostomia and dry eyes. Many other tissues may be affected as well. Early recognition of this disease may help to alleviate signs and symptoms and is, thus, important. The aim of this paper is to provide the dentist with knowledge to enable him to timely diagnose the oral component of Sj?gren's syndrome as well as to give guidelines for the treatment.     

Effect of laser irradiation on the permeability of bovine dental enamel

The transport of ionic and non-ionic compounds through bovine dental enamel was measured before and after irradiation with a carbon dioxide laser (energy density 10J/cm²). The irradiation increased the permeability of enamel rather than decreased it as postulated by other workers to explain the increased resistance to surface demineralization produced by such irradiation.     

Supplementary insurance: yes or no? An investigation into the motives of patients

Of the group of dentate adults taking part in the Public Health insurance scheme, 78% has opted for a supplementary insurance for dental care after the dental health care reform on January 1, 1995. For edentulous people this figure is 33%. Both for people who choose for a supplementary insurance and for those who did not, financial motives were most important. For the dentates visiting a dentist regularly, the time period between two check-ups has grown from 6.0 months to 6.9 months. The extent to which check-ups are postponed is not different for people with or without a supplementary insurance for dental care.     

Plasma antibody levels in periodontitis patients and controls

BACKGROUND: A major aspect of the adaptive host response in periodontitis is the production of antibodies. Several risk and susceptibility factors for periodontitis, including smoking, age and composition of the subgingival microflora, have also been suggested to influence antibody production. AIM: The present study was conducted to investigate plasma levels of immunoglobulin (Ig) G, A and M antibodies in periodontitis patients of Caucasian European heritage in relation to disease severity, smoking, diagnosis and prevalence of periodontopathogens. METHODS: In this study, 29 patients with severe periodontitis, 51 with moderate periodontitis and 55 controls without periodontal destruction were enrolled. From the total of 80 patients, 18 were diagnosed with aggressive periodontitis and 62 with chronic periodontitis. Total IgG, IgA and IgM as well as IgG isotypes were analyzed in plasma samples. RESULTS: Levels of total IgG, IgA and IgM were not different between patients and controls; however, in periodontitis, higher levels of IgG1 and IgG2 were observed. Smoking appeared to be significantly and inversely related to antibody levels in periodontitis, in particular for total IgG and IgG2. The absence of an elevated total IgG and IgG2 in smoking patients was irrespective of severity, prevalence of periodontal pathogens and diagnosis. The elevation of total IgG and IgG1 and IgG2 in non-smoker periodontitis patients was observed in patients with moderate periodontitis and even greater in patients with severe periodontitis, but was independent whether patients were infected with Actinobacillus actinomycetemcomitans or Porphyromonas gingivalis and independent of diagnosis. Clinically, it was observed that patients who smoked had more periodontal bone loss; the current findings on antibody levels may be one of several mechanisms related to more extensive periodontal breakdown in smoker patients. CONCLUSION: The current study shows that non-smoker periodontitis patients have higher levels of total IgG and IgG2 than smoker periodontitis patients.     

Biologic outcome of single-implant restorations as tooth replacements: a long-term follow-up study

Background: The replacement of a single tooth or several teeth by means of single‐implant restorations is an increasingly used method that needs long‐term validation. Purpose: The goal of this study was to evaluate the outcome of single‐implant restorations by means of fixed restorations and to define the prognosis through marginal bone level estimations. Materials and Methods: From November 1986 to June 1998, 270 Brånemark implants (215 in the upper jaw) were installed in 219 patients (106 males). Both anterior and posterior sites were involved. Of the 263 single restorations, 28 were placed in private dental offices. The patients were followed until June 1999. Results: Twelve implants failed before or at abutment connection or within 6 months afterward. Only four implants failed later. The cumulative success rates were 93% for the implants and 96.5% for the restorations over a period of 11 years. The marginal bone loss during the first 6 months after abutment connection reached 0.71 mm and then dropped to 0.036 mm annually over a period of 10 years. Conclusions: Single‐implant restorations (Brånemark System) are a reliable treatment with a good long‐term prognosis. Failures were concentrated during the healing period and early loading phase.     

Intra-familial transmission and distribution of Prevotella intermedia and Prevotella nigrescens

The periodontal bacteria Prevotella intermedia and Prevotella nigrescens have been recently separated from each other. The purpose of this study was to investigate the distribution and routes of transmission of these bacteria among family members. Seven patients with moderate to severe periodontitis were selected. These probands, their spouses and 14 of their children were investigated. The presence of Pr. Intermedia and Pr. nigrescens was determined by culture techniques in pooled subgingival plaque samples, in the saliva, on the tongue, tonsils and buccal mucosa. Differentiation of Pr. intermedia and Pr. nigrescens was performed by enzyme electrophoretic mobility. From all 7 patients, as well as 4 spouses and 3 of the children, Pr. intermedia could be isolated. Pr. Nigrescens was found in 2 of the 7 patients, in 5 of the spouses and in 5 of the 6 children aged 5–10 yr. In the 8 children aged 0–4 yr both species were seldom isolated. These data are in accordance with earlier findings that Pr. Intermedia is associated with periodontitis and Pr. Nigrescens with a relatively healthy periodontal condition. Ribotyping of bacteria was performed by hybridization of Hindlll restriction endonuclease digests of chromosomal DNA with ribosomal DNA. Isolates from unrelated individuals always had distinct ribotypes. Indistinguishable ribotypes of Pr. intermedia and Pr. Nigrescens were found both among married couples and among parents and children. This indicates that intrafamilial transmission of Pr. intermedia and Pr. Nigrescens is possible both between adults and between parents and children.