Periodontal findings in elderly patients with non-insulin dependent diabetes mellitus.

The periodontal status of 25 patients with non-insulin dependent diabetes mellitus (NIDDM) (age range 58 to 76) was investigated and compared with 40 non-diabetic control subjects (age range 59 to 77). Surfaces with visible plaque and bleeding after probing, calculus, recessions, and pathological pockets were examined. The total attachment loss was calculated as a sum of recessions and pockets in millimeters. Mesial and distal bone loss was measured from panoramic radiographs and mean alveolar bone loss was calculated. Periodontal disease was considered advanced when mean alveolar bone loss was over 50%, or 2 or more teeth had pockets > or = 6 mm. Microbiological analysis comprised the detection of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus by a polymerase chain reaction (PCR) method. Patients with NIDDM had significantly more often advanced periodontitis than control subjects, 40.0% and 12.5%, respectively. Diabetic patients did not harbor more pathogens than the control subjects. The HbA1C level deteriorated in patients with advanced periodontitis, but not in other patients with NIDDM, when compared to the situation 2 to 3 years earlier. Advanced periodontitis seems to be associated with the impairment of the metabolic control in patients with NIDDM, and a regular periodontal surveillance is therefore necessary.

Neurophysiological mechanisms of dentin hypersensitivity.

In hypersensitive teeth pain is typically induced by cold and hot fluids or foods brought to contact with the sensitive dentin or by osmotic and mechanical stimuli. The results of animal experiments indicate that intradental A-type nerve fibres are responsible for the sensitivity of dentin. They are most probably activated by the hydrodynamic mechanism. Thus, their activation is to a great extent dependent on the condition of dentin with either open or blocked dentinal tubules. Blocking of the tubules effectively prevents the nerve activation. Correspondingly, in human experiments, the condition of the dentinal tubules greatly affects dentin sensitivity. In clinical studies significantly more open tubules are found in sensitive compared to non-sensitive areas. However, hypersensitivity may sometimes persist despite of effective blocking of the tubules. This may indicate that some other mechanisms may operate in the nerve activation instead of, or in addition to the hydrodynamic one. Inflammation may sensitize the nerve endings to such an extent that smaller fluid shifts would be sufficient for nerve activation or, for example, thermal stimulation may activate the nerves by a direct effect. On the other hand, spontaneously occurring changes in the exposed dentin, which in many cases seem to block the tubules may reduce the responses to hydrodynamic stimulation and, thus, have an opposite effect on dentin sensitivity. The results of animal experiments indicate that functional changes of this kind may occur. These results also indicate that real dentin hypersensitivity can develop as a result of inflammation induced sensitization of the nerves in the pulp-dentin border in teeth with open dentinal tubules.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of airpolishing on dental plaque removal and hard tissues as evaluated by scanning electron microscopy.

The effect of an air-powder abrasive system on dental hard tissues was tested on 20 volunteers. Impressions of 150 randomly selected areas were taken before and after airpolishing and positive replicas were prepared for scanning electron microscopic examination (SEM). The amount of dental plaque on tooth surfaces was reduced by the treatment (P less than 0.001). The abrasive changes caused by airpolishing on enamel were greater on the surfaces covered by dental plaque before the airpolishing compared to the surfaces without plaque (P less than 0.01). The enamel and cemental surfaces were more abraded after the treatment compared with the initial condition. Despite the effectiveness of the dental airpolishing technique, the negative aspects should be considered in the decision to use airpolishing in routine prophylaxis, especially in patients with root surfaces exposed to the oral cavity.

The gingival effects of dental airpolishing as evaluated by scanning electron microscopy.

An air-powder abrasive system was tested among 20 volunteers, who had healthy gingiva or slight gingivitis, but no periodontal pockets. Impressions of randomly selected areas (n = 103) were taken before and after airpolishing and positive replicas were prepared for scanning electron microscopy (SEM). Gingival bleeding increased statistically significantly (p less than 0.001) during the treatment. Also gingival erosive changes were increased when using airpolishing technique (p less than 0.001). The erosive changes observed by SEM and the subjective symptoms during and after the operation positively correlated to the presence of gingival inflammation (p less than 0.001). It can be concluded that also the negative aspects of the airpolishing technique should be taken into consideration, especially when operating near the gingival margin.

Pseudocholinesterase activity and its origin in human oral fluid.

Pseudocholinesterase (PCE) activity in oral fluid of 31 male and 24 female subjects was determined using butyrylthiocholine iodide as substrate. Males had approximately twice as much salivary PCE activity as did females [4.8 +/- 2.4 (S.D.) U/1 and 2.2 +/- 1.5 (S.D.) U/1, respectively]. The activity was not much affected by salivary flow rate, although in men it was a little higher in stimulated than in unstimulated saliva. Salivary PCE activity showed diurnal variation. Accordingly, activities were about three times greater at four a.m. than at four p.m. Parotid PCE activity correlated with that of whole saliva in both men and women. PCE activity in crevicular fluid (four subjects) was 120 +/- 48 (S.D.) U/1. An elevation of PCE activity in oral fluid was found after experimental induction of gingival inflammation. However, the mean PCE activity of patients with clinical gingivitis was not significantly higher than that of healthy subjects, although some exceptionally high values were found. Sonicated samples of plaque did not contain any PCE activity. No correlation existed between PCE activities in saliva and serum.

Effect of Zn and Mg on the formation of whitlockite in human subgingival calculus.

X-ray diffraction analyses were carried out from pooled samples of old subgingival calculus. Also the concentration of Ca, Mg, Zn, Sr, Pb, Fe and Cu from these samples were determined by means of atomic absorption spectrophotometry. The comparison of the samples containing almost the same Zn concentration and two different concentrations of Mg (9 mg/g and 16 mg/g) showed an increase of 2.0.10 and 220 whitlockite reflections with an increasing Mg concentration. The increase of Mg concentration shifted whitlockite reflections suggesting a contraction of a-axis. The increase of Zn concentration showed an increase of 2.0.10 and 220 reflections indicating the fitness of Zn into the lattice of whitlockite. No changes of a-axis were detectable. When comparing all diffractograms and the results obtained from chemical analyses, the presence of Zn-MG-whitlockite proved evident.

Concentrations of Ca, Mg, Mn, Sr and Zn in supra- and subgingival calculus.

The concentrations of Ca, Mg, Mn, Sr and Zn in supra- and subgingival calculus collected from mandibular anterior teeth mainly of the same persons were analyzed with atomic absorption spectrophotometry. The results showed highly significantly (P less than 0.001) greater Zn and Sr concentrations in subgingival samples. The mean value of Zn was 5.4 times higher in subgingival calculus than in supragingival calculus. In contrast, the concentration of Mn was significantly (P less than 0.01) higher in supragingival calculus. The difference in the concentration of Mg in supra- and subgingival calculus was highly significant (P less than 0.001) only when samples from the same person were compared. The concentration of Ca was very similar in both types of calculus and individual variations were very small.