[Periodontitis and systemic diseases: from science to clinical practice]. / Parodontitis en systemische ziekten - van wetenschap naar praktijk.

The evidence for an association between systemic diseases and periodontitis is strongest with diabetes mellitus type 2 and cardiovascular disease. There is a moderate association of periodontitis with adverse pregnancy outcomes and rheumatoid arthritis. Periodontal treatment has, on average, a positive effect on reducing systemic infection and improving the condition of the vascular system. For diabetes patients, periodontal treatment can also have a positive effect on metabolic regulation. There is insufficient evidence that periodontal treatment prevents adverse pregnancy outcomes and rheumatoid arthritis.

Shifts in the microbial population in relation to in situ caries progression.

The shift in microbial diversity from young to mature plaque, related to caries activity on sound and restored surfaces, was studied using denaturing gradient gel electrophoresis. During a 20-week in situ study on caries progression 8 subjects wearing restored and unrestored dentin and enamel sections, biofilm was sampled after 1 and 20 weeks (young or mature plaque). A higher microbial diversity (mature plaque) was seen in caries-active compared to caries-free subjects. Rothia dentocariosa and Scardovia inopinata were absent from all caries-free sites, but appeared in 50% of the caries-active sites.

Bacterial composition and red fluorescence of plaque in relation to primary and secondary caries next to composite: an in situ study.

BACKGROUND/HYPOTHESIS: Secondary caries has been suggested as the main reason for restoration replacement. We hypothesized that more caries-associated bacteria are found on composite resin restoration material, compared to sound tooth tissue. METHODS: Both restored and unrestored dentin and enamel samples were placed in a full denture of eight subjects for 20 weeks. The microbiological composition of approximal plaque and the association between caries-associated bacteria and red autofluorescence of dental plaque was studied. Every 4 weeks the specimens were microradiographed using transversal wavelength independent microradiography (T-WIM). After 1 and 20 weeks red fluorescence pictures and plaque samples were taken. Samples were cultured for total anaerobic counts, mutans streptococci, lactobacilli, candida and Actinomyces odontolyticus. RESULTS: Lesion depth in the dentin and enamel was positively associated with lactobacilli, and lesion depth in dentin was positively associated with A. odontolyticus, whereas no association was found between mutans streptococci and lesion depth. The red-fluorescent bacteria A. odontolyticus and lactobacilli did not correlate with red-fluorescent plaque, indicating that red fluorescence is probably not caused by a single species of these bacteria. After 20 weeks, a higher proportion of combined mutans streptococci and lactobacilli was found on restored tissue compared to non-restored tissue (P = 0.04). CONCLUSION: The higher proportion of caries-associated bacteria on restored tissue indicates that the ecology on the surface of primary lesions differs from that on lesions next to composite, and that secondary caries next to composite may differ from the primary caries process.

Approximal secondary caries lesion progression, a 20-week in situ study.

There is no consensus about the definition and progression of outer and wall lesions in secondary caries. In this study we investigated whether lesion progression is influenced by an adjacent composite restoration and whether wall lesions develop at the composite-tooth interface. In order to study the appearance and progression of approximal primary caries lesions and lesions next to composite restorations, 16 samples were placed in a full denture of each of 8 subjects. Each denture housed 4 restored and 4 unrestored enamel samples and similarly 8 dentin samples. All samples were distributed over 2 sample holders, in each of which 4 approximal spaces were simulated. Every 4 weeks the sample holders were microradiographed using transversal wavelength independent microradiography and lesion depth was measured. At the end of the study, after 20 weeks, the lesion depth of the outer lesions was 0-350 microm for enamel and 0-750 microm for dentin. The estimated difference in progression between secondary and primary lesions (1.1 microm/4 weeks, 95% CI: -9.2 to 11.4 microm) was not statistically significant (p = 0.83). Secondary outer lesions appeared and progressed as primary caries lesions. No clear wall lesions were found next to composite, but they were observed next to acrylic resin.

Red autofluorescence of dental plaque bacteria.

Red autofluorescence of plaque and its relation to fluorescence of a single species in the biofilm was studied. Fluorescence images of non-disclosed and disclosed plaque of 28 first-year students were captured. The plaque samples were assessed by culture methods and studied for red autofluorescence. Species capable of producing red autofluorescence were cultivated from subjects with and without red plaque autofluorescence. Red autofluorescence was observed from Actinomyces odontolyticus, Prevotella intermedia and from Porphyromonas gingivalis and Peptostreptococcus micros grown together. The microbial findings indicated that the intrinsic characteristics of the mature biofilm itself are more responsible for the red autofluorescence than the characteristics of the single species.

Transversal wavelength-independent microradiography, a method for monitoring caries lesions over time, validated with transversal microradiography.

This paper describes a microradiographic method for measuring mineral concentration in a transversal geometry with thick (< or =3.2 mm) sections: transversal wavelength-independent microradiography (T-WIM). It was tested on bovine enamel and dentin samples in vitro, and the results were validated with those of transversal microradiography (TMR). 48 enamel and 48 dentin samples (3.2 x 3.2 x 1.5 mm) were embedded in acrylic resin, randomly divided into six groups of 8 dentin or 8 enamel samples, and demineralized for 0 (sound control), 1, 2, 3, 4, or 5 weeks. For T-WIM, samples were imaged on film with polychromatic 40-kV Cu X-rays with an Al (0.25 mm)/Ni (0.02 mm) filter together with an aluminium/zinc step wedge. TMR slices (about 80 mum for enamel and about 130 mum for dentine) were subsequently cut from the centre of the samples and subjected to TMR. Microradiographs from both methods were digitized and image analysis software was used to calculate lesion depth and mineral loss. The relations between T-WIM and TMR results for mineral loss (DeltaZ) and lesion depth were nearly linear (r > or = 0.96) for both enamel and dentin. The slopes of the regression lines were between 0.99 and 1.02 except for DeltaZ in dentine, which was 0.89. It was concluded that T-WIM is a suitable method for TMR on thick samples.

[Research methods in dentistry. 6. In vivo and in vitro methods for studying caries lesion progression]. / Onderzoeksmethoden in de tandheelkunde. 6. Methoden om de progressie van cariëslaesies in vivo en in vitro te onderzoeken.

This paper describes some of the most used methods for caries lesion progression measurement in in vivo and in vitro research. Clinical measurements are usually limited to visual inspection. Currently available scoring systems and statistical analyses, making use of changes in lesion stage, have the potential to make caries clinical trials more efficient. A method for light fluorescence measurements is capable of measuring small changes in mineral loss for early lesions, In the laboratory, mainly destructive methods are used. The most widely accepted gold standard at the moment is transversal microradiography (TMR). Other microradiographical methods are described, that allow for longitudinal measurements.