Adhesion of Porphyromonas gingivalis strains to cultured epithelial cells from patients with a history of chronic adult periodontitis or from patients less susceptible to periodontitis

BACKGROUND: The present study aimed to explain the interindividual variation in periodontitis susceptibility by differences in the initial adhesion rate of Porphyromonas gingivalis to the pocket epithelium of these individuals, and/or by inter-P. gingivalis strain differences in association capacity (adhesion and internalization). METHODS: Adhesion assays were performed on epithelial monolayers (cultured in vitro from pocket epithelium belonging to patients who were less or more susceptible to chronic adult periodontitis) using 11 genetically different clinical strains of P. gingivalis. RESULTS: Both the disease category (less susceptible versus susceptible) and the interstrain variation were found to have a significant effect (both P <0.05) on the initial bacterial association. The chronic adult periodontitis group showed significantly more association of P. gingivalis when compared to less susceptible patients (4.2 x 10(6) versus 3.5 x 10(6)). Also, the interstrain variation was significant, with strains Pg 4 and 5 representing the least and best associating bacteria (1.8 x 10(6) colony forming units for Pg 4, 9 x 10(6) for Pg 5). CONCLUSIONS: These results indicate that periodontitis susceptibility is influenced by both the interindividual differences in pocket epithelium (allowing more adhesion of P. gingivalis) or by the strain type by which the patient is infected (intra-species differences in adhesion capacity).     

CT diagnosis of synovial chondromatosis of the temporomandibular joint

Synovial chondromatosis of the temporomandibular joint (TMJ) is a very rare condition. It is characterised by the presence of loose bodies in the joint space. Clinical signs, histopathological findings and radiography play an important role in the diagnostic process. Conventional X-rays have shown to be of limited value, for they fail to depict the intra-articular loose bodies in a significant amount of cases. Axial as well as coronal computer tomography (CT) is extremely useful in detecting loose bodies in the temporomandibular joint (TMJ). In this report we present and discuss a further case, and the use of CT in the diagnosis of TMJ-synovial chondromatosis is illustrated.     

Assessment of denture satisfaction

The aim of this investigation was to evaluate the reliability and validity of a complaints questionnaire, designed to measure different aspects of denture satisfaction. Two groups of patients with full maxillary and mandibular dentures participated in the study. The patients in Group 1 (n = 113) were on a waiting list for new dentures, patients in Group 2 (n = 102) had recently had new dentures fitted. Five denture complaint scales were constructed from the questionnaire. The internal consistency (coefficient alpha) of the scales varied from 0.65 to 0.92. Furthermore, the scales showed a discriminatory ability between the patient groups (P less than or equal to 0.001) and significant Pearson correlation coefficients with satisfaction-related questions (r = 0.25-0.79). The scores on the scales can be considered a quantitative measure of denture satisfaction.     

Sealing ability of a new polydimethylsiloxane-based root canal filling material

We tested the null hypothesis that there is no difference in the sealing ability of GuttaFlow, RoekoSeal, and AH26 in root canals. Sixty extracted mandibular premolars were filled with AH26 (lateral compaction), RoekoSeal, or GuttaFlow (modified single-cone). The sealing ability of the root canal fillings was measured weekly (4 weeks) by using a glucose penetration model. Kruskal-Wallis test revealed significant differences in glucose penetration between the experimental groups at weeks 1, 2, 3, and 4. Whereas GuttaFlow showed the highest amount of leakage at all times, AH26 showed the lowest. There was no significant difference between RoekoSeal-filled and AH26-filled root canals throughout the experimental period. AH26 showed better sealing ability in root canals than GuttaFlow.     

Effect of Compromised Cortical Bone on Implant Load Distribution

Purpose: To investigate photoelastically the difference in load distribution of dental implants with different implant neck designs in intact and compromised bone. Materials and Methods: Composite photoelastic models were fabricated using two different resins to simulate trabecular bone and a 1‐mm thick layer of cortical bone. The following parallel‐sided, threaded implants were centrally located in individual models representing intact and compromised cortical bone: Straumann (4.1‐mm diameter × 12‐mm length), AstraTech (4.0‐mm diameter × 13‐mm length), and 3i (3.75‐mm diameter × 13‐mm length). The compromised cortical bone condition was simulated by contaminating a 1‐mm neck portion with Vaseline to impair the implant–resin interface. Vertical and oblique static loads were applied on the abutments, and the resulting stresses were monitored photoelastically and recorded photograhphically. Results: For the fully intact condition, the highest stresses were observed around the crest and apical region for all implant designs under vertical and inclined loads. There were no appreciable differences in magnitude or distribution between implant types. With compromised cortical bone, for all designs and load directions, higher stresses in the supporting structures were observed. Increased stresses were noted especially at the cortical bone–trabecular bone interface. Somewhat lower stress levels were observed with the 3i implant. Conclusions: The condition of implant–cortical bone contact has considerable influence on stress distribution. A compromised cortical bone condition caused higher level stresses for all implant designs tested.     

Women with a recent history of early-onset pre-eclampsia have a worse periodontal condition

OBJECTIVE: Pre-eclampsia is a complication of pregnancy characterized by systemic vascular dysfunction and pathological changes in placental arteries. Growing evidence of chronic infection as an aetiological factor in vascular diseases prompted us to study maternal periodontal disease in subjects with early-onset pre-eclampsia (<34 weeks). METHODS: A case-control study was carried out on 17 early-onset pre-eclamptic women and 35 controls with uncomplicated pregnancies in a period of 3-28 months postpartum. All were Caucasians. Full-mouth periodontal examinations were performed to determine the periodontal condition. Subgingival-plaque samples were analysed by anaerobic culture techniques for the presence of seven bacterial periodontal pathogens. Potential confounders as age, smoking, educational level and body mass index were determined. RESULTS: Severe periodontal disease was found in 82% of the pre-eclamptic and in 37% of the control group (p=0.009). After adjusting for age, smoking and educational level, the odds ratio was 7.9 (95% CI: 1.9-32.8). The periodontopathic microorganism Micromonas micros was more prevalent in the case group (p=0.040) while Campylobacter rectus was more prevalent in the control group (p=0.047). CONCLUSION: These results indicate that Caucasian women with a recent history of early-onset pre-eclampsia have a worse periodontal condition, as compared with women with uncomplicated deliveries.     

Oral health status of institutionalized elderly Cape Coloreds from the Cape Peninsula of South Africa

A study has been conducted to assess the oral health status and need for dental treatment among elderly Cape Coloreds resident in homes for the aged in the Cape Peninsula of South Africa. This paper describes the prevalence of diseases of the mouth with special reference to denture-induced lesions and white lesions of the oral mucosa. Dental caries was the most prevalent oral lesion (27.2%). The most common conditions of the soft tissues were leukoedema (24.4%) and leukoplakia (4.4% for the tongue; 20.4% for the remainder of the oral mucosa). Leukoedema and leukoplakia showed statistically highly significant correlations with tobacco habits. Men more commonly had a tobacco habit than women (P less than 0.002) and leukoplakia, leukoedema and depigmented lesions of the lips were significantly more common in men than in women. No significant difference could be proven statistically when the frequency of irritative fibrous hyperplasia in females was compared with that in males.     

Carbohydrate metabolism of Streptococcus mutans in dental plaque in gnotobiotic rats.

The fermentation products of Streptococcus mutans C67-1 were investigated in fissure plaque of rats, that were mono-associated with this strain. In addition to lactic acid, acetic acid and ethanol were present. The finding that a mixed acid fermentation occurred and that ethanol was produced suggests that the carbohydrate source rather than the nitrogen source was the growth-limiting substrate for Strep. mutans in plaque.