Oral health indicators poorly predict coronary heart disease deaths.

Several earlier studies have suggested that development of coronary heart disease (CHD) is causally related to oral infections. The aim of this study was to investigate the association between oral health indicators and CHD deaths. Out of a nationally representative sample, 6527 men and women aged 30-69 years participated in the health examination with a dental check. Detailed oral health data included caries, periodontal and dental plaque status, presence of remaining teeth, and various types of dentures. Over a mean 12-year follow-up, persons dying of CHD were older and more often smoked, had hypertension, hypercholesterolemia, diabetes, and only a basic education compared with other persons. In univariate analyses, several oral health indicators were associated with CHD deaths. Adjustment for the established CHD risk factors reduced all these associations to statistical non-significance. The associations between oral health indicators and CHD are mostly explained by confounding factors, particularly those relating to health behavior.

Evaluation of salivary tests and dental status in the prediction of caries increment in caries-susceptible teenagers.

We evaluated caries increment in connection with salivary caries-related findings and dental status in teenagers by carrying out a retrospective follow-up, lasting on average 28 months. A total of 66 adolescents, mean age 15.2 years, were selected by their susceptibility to caries, as clinically defined at a routine checkup. Their baseline DMFT was 5.7, compared to 4.3 in the root population of 230 patients. Increment of caries on selected surfaces (delta DFSs) included new caries reaching the dentine and new fillings done due to such caries. Delta DFSs > 0 was taken as the validation criterion to define a caries case. Screening criteria for salivary tests were set as follows: flow rate of unstimulated saliva less than 0.2 ml/min, and of stimulated saliva less than 1.0 ml/min; buffering capacity: final pH below 4.5, mutans streptococci (SM) score of 2 or 3 (> or = 10(5) CFU/ml), and lactobacilli (LB) score of 5 or 6 (> or = 10(5) CFU/ml). Mean delta DFSs per subject was 1.1, with 70% of these new DF findings being on occlusal surfaces. Delta DFSs was correlated with LB (0.31) for both genders, for boys only with buffering capacity (-0.34), and for girls only with flow rate of stimulated saliva (-0.28) and DMFT (0.35). The highest sensitivities of salivary tests for caries were shown by LB (0.82) and SM (0.64), their specificities being 0.63 and 0.59, respectively. Positive predictive values of the five tests varied between 0.69 and 0.89. Predictions based on DMFT showed a sensitivity of 0.87 for DMFT > 3, but only of 0.33 for DMFT > 7, the corresponding specificities being 0.44 and 0.81.

Association between root caries occurrence and periodontal state.

To analyze the occurrence of root caries in relation to the periodontal state, we examined clinically a representative sample (n = 4,777) of Finish adults, aged 30 years and older. Our definition of root caries included primary decay on root surfaces, and a subject's periodontal state was described according to the presence or absence of gingival inflammation or periodontal pockets and subgingival calculus and/or overhangings. Subjects with a healthy periodontium seldom (4%) had any caries on root surfaces, whereas 15% had caries in conjunction with gingival inflammation, and 17% in conjunction with deepened pockets. The deeper the pockets, the greater the frequency of root caries for men, but not for women. Subgingival plaque retention showed a strong association with root caries. As the study population represented Finnish adults, the results can be generalized with reasonable confidence.

Effects of carbon dioxide, Nd:YAG and carbon dioxide-Nd:YAG combination lasers at high energy densities on synthetic hydroxyaptite.

The aim of this study was to determine the crystalline structure and chemical alterations of synthetic hydroxyapatite after irradiation with either CO2, Nd:YAG or CO2-Nd:YAG combination lasers at high energy densities of 500-3,230 J.cm2. Further, dissolution kinetics of the lased material were analysed and compared with those of unlased apatite. Electron microscopy showed that the lased material consisted of two kinds of crystals. From the micrographs their diameters varied from 600 to 1,200 A and from 3,000 to 6,000 A, respectively. The larger crystals showed 6.9-Angström periodic lattice fringes in the transmission electron microscope. alpha-Tricalcium phosphate (TCP) was identified by X-ray diffraction. Selective-area electron diffraction identified the large crystals to consist of tricalcium phosphate while the smaller crystals were probably hydroxyapatite. Assays of dissolution kinetics showed that at these high energy densities lased material dissolved more rapidly than unlased synthetic hydroxyapatite due to the higher solubility of TCP.

Irradiation of human dental tissues with CO2-, Nd:YAG-, and CO2-Nd:YAG combination laser.

Extracted third molars were used to study the effect of Nd:YAG laser irradiation combined with CO2 laser beam on dental hard tissues. The specimens were studied with SEM after lasing and the size of the impact areas and beam penetration into enamel and dentin were planimetrically analyzed. High-energy CO2 laser (e.g. 10 s irradiation with 10 W output energy) penetrated all enamel and dentin. The simultaneous addition of Nd:YAG irradiation to the CO2 beam was found to increase the effect of CO2 laser, while Nd:YAG irradiation alone, used with equivalent energy densities, did not cause any effect on enamel surface. Thus, Nd:YAG laser was found to potentiate statistically significantly the effect of CO2 irradiation, but the morphologic alterations on dental hard tissues, such as crater formation at the beam focus site, appeared to be due to CO2 irradiation alone.

Remaining teeth in Finnish adults related to the frequency of tooth-brushing.

The number of teeth remaining in adults was evaluated with specific reference to the frequency of tooth-brushing. The sample consisted of 5028 dentate subjects, representing the Finnish population aged 30 years and older. Their mean age was 47.5 years. The presence or absence of each individual tooth was recorded. A total of 91,332 teeth was registered. Forty-eight per cent of the women had retained no fewer than 21 teeth, 20% had 20-11 teeth, and 32% had 10-1 teeth. For men the percentages were 52%, 23%, and 25%, respectively. The number of a subject's remaining teeth was strongly related to the frequency to tooth-brushing (p less than 0.001). The more frequent it had been, the more teeth the subjects, both women and men, had retained. This trend was also seen for the teeth in each jaw, and even for type of tooth. The trend was also present when the number of teeth was analyzed in accordance with a subject's income.

Wearing of removable partial dentures in relation to periodontal pockets.

Using a representative sample of 5028 dentulous Finnish adults the occurrence of periodontal pockets was studied separately for the maxillae and the mandibles among removable partial denture (RPD) wearers and non-wearers. RPD(s) were worn in 11.2% of the 3444 maxillae with at least four natural teeth remaining, and in 7.7% of the 4706 corresponding mandibles (P less than 0.001). Periodontal pockets were more frequently observed in maxillae than mandibles. Wearing of RPDs highly significantly (P less than 0.0001) increased the odds of having periodontal pockets in general (4 mm or more) as well as the odds of having deeper periodontal pockets (exceeding 6 mm). This phenomenon was observed both in the maxillae and in the mandibles. These results suggest that wearing of RPD is a threat to periodontal tissues and that dentists should take care to frequently recall their patients fitted with RPD(s). During the recall visits more attention should be paid to the periodontal conditions of patients wearing RPD(s).

Wearing of removable partial dentures in relation to dental caries.

Using a representative sample of 5028 dentulous Finnish adults the occurrence of dental caries was studied among removable partial denture (RPD) wearers and non-wearers. Of the subjects wearing no RPD(s) 61.4% had one or more carious teeth, among those wearing a single RPD the figure was 60.5% and among those wearing RPDs in both jaws 62.7%, respectively. When sociodemographic background, other oral status measures than caries and oral health care habits were simultaneously controlled, subjects wearing RPDs in both jaws had slightly increased (P less than 0.05) probability of having one or more carious teeth compared to those with no RPD(s). Subjects with a single RPD did not have a statistically significantly increased probability of having carious teeth. Among those 3075 subjects who had one or more carious teeth the wearing of one or two RPDs did not significantly increase the number of carious teeth. Because the subjects wearing RPDs in both jaws were seen to have a slightly increased risk of having caries, this confirms the view that dentists should emphasize good oral hygiene habits and regular dental attendance among RPD wearers.

Occurrence of root caries in relation to dental health behavior.

We studied the relationship between the occurrence of untreated root caries and a subject's dental health habits, such as the frequency of tooth-brushing, the avoidance of sugar, and regularity of dental visits. A representative sample of 5028 adults was examined. Information on dental health habits was collected by professional interviewers one to six weeks before the clinical examination. A high frequency of tooth-brushing was strongly related to a low occurrence of root caries. The use of sugar in coffee or tea was strongly associated with root caries occurrence among men. The use of sweets was related to root caries occurrence moderately in men but not at all in women. Regular dental check-up behavior was strongly related to an infrequent occurrence of root caries. It was concluded that dental health behavior influences root caries occurrence and that caries on root surfaces is associated with poor dental health habits. Age and gender differences in root caries occurrence, reported earlier, may relate to different dental health behavior of women and men.

Subjective need of removable denture treatment in Finnish adults.

The aim of this study was to analyse the clinical dental health, use of dental services and socio-economic factors correlating with the subjective need for removable dentures in Finnish adults aged 30 years and older. A total of 2528 persons who had lost one or more natural teeth (wisdom teeth excluded) and who had not been provided with any dentures, were selected for this study. Subjects who had subjective need for prosthetic treatment had statistically significantly fewer teeth and fewer fillings, and more decayed teeth than others. Irregular users of dental services felt the need for a prosthesis more often than did regular users of those services. Irregular brushing of teeth was also associated with a greater need for prosthetic treatment. Men, older individuals and persons with less education and a smaller family income felt the need for prosthetic treatment more often than women, younger individuals and better educated persons. The factors differentiating between the two groups with and without a subjective prosthetic treatment need were analysed by discriminant analysis. The best differentiating factors were frequency of dental visits, caries score, frequency of brushing teeth, family income, number of fillings and sex.