Distribution of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis by subject age.

The possible associations between periodontitis subject age and the distribution of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were examined using an extensive data bank of subgingival plaque specimens analyzed using DNA probes. The results suggest that A. actinomycetemcomitans is strongly related to subjects in the youngest age group (10 to 19 years) with decreasing prevalence and concentration levels in older age groups. In contrast, P. gingivalis showed a reverse relationship to subject age with highest prevalence and concentration levels in older subjects (30 years and older) compared to subjects in younger age groups. Statistical testing of these relationships were highly significant. (P less than 0.0001).     

Effectiveness of chlorhexidine and sodium fluoride in reducing dentin hypersensitivity.

This investigation was conducted to evaluate the effect of chlorhexidine, sodium fluoride, and sequential rinses of chlorhexidine (Cx) and sodium fluoride (NaF) on dentin hypersensitivity. Forty-four adult patients with dentin hypersensitivity on three teeth were randomly assigned to receive one of four treatment rinses: (1) placebo; (2) 0.12% Cx; (3) 0.2% NaF; or (4) 0.12% Cx plus 0.2 NaF. Patients' responses to cold stimulation were recorded at baseline, two weeks, and four weeks. Pain response was quantified by applying successively decreasing temperature intervals of water (20 degrees C, 15 degrees C, 10 degrees C, 5 degrees C, and 0 degrees C) to exposed dentin. Plaque Index (Silness and L?e) was recorded at baseline only. Data on dentin sensitivity over time were analyzed using a repeated measures ANOVA. This ANOVA was conducted to generate an error term for calculation of Dunn's multiple mean comparison test. A Spearman rank order test was computed to assess correlation between plaque and hypersensitivity at baseline. Results showed the Cx and NaF rinses alone significantly reduced hypersensitivity (p less than .01) at four weeks compared to baseline. Sequential Cx and NaF rinses significantly decreased sensitivity (p less than .01) at both the two- and four-week intervals compared to baseline. At the four-week interval, the sequential Cx/NaF rinse group showed a significantly greater reduction (p less than .01) in hypersensitivity response when compared to placebo. Cx alone, or NaF alone groups. A moderate, positive correlation (r = 0.55) was demonstrated between plaque and dentin hypersensitivity. This was statistically significant at the (p less than .05) level.     

Effect of dentin adhesives on sealant bond strength.

This study evaluated the effect of four dentin adhesives on sealant shear bond strength. Five groups of 15 human extracted teeth (75 in total) were prepared to receive the following treatments: group 1, sealant only; group 2, sealant plus gluma primer; group 3, sealant plus gluma primer and sealer, group 4, sealant plus C & B Metabond. Each tooth had a bonding site prepared for each material by grinding a flat plane on the enamel with 600 grit. The enamel site was etched for 30 seconds, washed for 20 seconds and dried. Each material was mixed according to the instructions of the manufacturer. The sealant (Concise) was placed in a nylon cylinder, light-cured, stored in distilled water for 24 hours, thermocycled (100 cycles at 5 to 55 degrees C) and shear bond strength determined with a knife-edge blade in an Instron running at a crosshead speed of 0.5 mm/min. The results in MPa were: group 1, 11.8 +/- 4.5; group 2, 12.3 +/- 5.0; group 3, 10.3 +/- 1.9; group 4, 12.5 +/- 8.6; and group 5, 15.8 +/- 5.2. Statistically (ANOVA one way) there was no significant difference in the groups.     

Cross-sectional assessment of caries and periodontitis risk within the same subject

Dental caries and chronic periodontitis may be synergistically associated, negatively associated, or completely independent. The present report examines this relationship by comparing the susceptibility to chronic periodontitis and caries within the same individual. From an 800-patient sample, a periodontitis risk score was derived by radiographic assessment of bone loss in quarters of optimum bone height and obtaining for each subject a mean score based on all measurable surfaces. Similarly the caries risk was determined radiographically from the total decayed and filled teeth (DFT), as a percentage of the total teeth measured. The Mantel-Haenszel technique was used for analysis of the relationship between periodontitis and caries and data was stratified on four categories of age, sex, and numbers of teeth present. This analysis revealed no systematic patterns, indicating that the risks of caries and periodontal diseases are unrelated (chi 2 = 0.00; 1 df; P greater than 0.50). In addition, a regression analysis, which was controlled for sex and age, indicated a marked lack of association between caries and periodontitis (P = 0.94). Thus, although these common diseases share putative etiologic factors such as oral hygiene practices and dental attendance pattern, the major risk factors are probably quite different.     

Dose-responsive characteristics of meperidine sedation in preschool children

Using double-blind conditions, 60 uncooperative and fearful preschool children (24-66 months) received intramuscular injections of meperidine 0.25, 0.50, 1.00 mg/lb or placebo prior to restorative dental treatment. Behavior was assessed by the dentist and an independent observer during five specific treatment procedures. Behavioral ratings found meperidine to be an effective sedative, with 0.50 mg/lb and 1.00 mg/lb being significantly more effective than placebo (P less than 0.05, Kruskal-Wallis). Children receiving 1.0 mg/lb of meperidine had significantly more nausea and vomiting than patients receiving lower doses of the drug (P less than 0.05, Chisquare). Physiologic monitoring demonstrated that the highest dose of meperidine was associated with transient drops in arterial oxygen saturation. Meperidine sedation was found to be more effective for older children (37-66 months) and for children initially rated as being only moderately uncooperative and fearful.     

Adenoid cystic carcinoma of the palate in a 9-year-old boy

Malignant tumors of salivary glands in children are extremely rare. A case of an adenoid cystic carcinoma affecting the palate in a 9-year-old child is described. This tumor has not previously been reported as affecting the minor salivary glands among patients in this age group.     

Xeroradiographic determination of effective setting expansion of a cristobalite investment

Previous studies of setting expansion of gypsum-bonded investments have not examined how wax patterns expand with time. The purpose of this study was to provide a method of measuring wax patterns during the setting reaction. Ten MOD inlay wax patterns were invested individually in plastic casting rings and imaged at specific intervals on a stage on which both the rings and xeroradiographic cassettes were fixed. Distances between the axiogingival proximal walls, axiopulpal proximal walls, and axial walls were measured at each interval. Reproducibility of measurements of xeroradiographic images was about 0.3%. After setting, the wax was burned out, and the rings were cooled to room temperature and cast in a Bi-Sn alloy that did not shrink upon solidification. The castings were measured and the means compared with the means of xeroradiographic measurements. There was no significant difference between the expansion means of the axiogingival or axiopulpal dimensions measured by casting or xeroradiographically (p greater than 0.05, two-tailed t test). Significant differences (p less than 0.05) were seen between means of the axial expansion measured by castings and xeroradiographically, suggesting the formation of a void at the proviral walls of the wax patterns. All horizontal expansion occurred between two and 22 min from the start of mix.     

Comparison of methods to assess neurosensory alterations following orthognathic surgery

Orthognathic surgery may damage branches of the trigeminal nerve, resulting in postoperative neurosensory disturbances. Alterations may be due to surgical edema, stretching, or direct trauma to the nerve. Lack of a standard and objective method of assessment hinders efforts to study and/or reduce the incidence of neurosensory disturbances. This study compared three methods of assessing neurosensory disturbances in patients who underwent bilateral mandibular ramus sagittal split osteotomies. Forty patients (26 female, 14 male) ranging in age from 23 to 47 years participated in the study. All of the patients had bilateral mandibular ramus sagittal split osteotomies and were stabilized with rigid skeletal fixation. Neurosensory testing was performed prior to surgery, and at 2 weeks, 1 month, 3 months, 6 months, and 1 year following surgery. Methods of assessment included two-point discrimination, threshold to electrical stimulation, and somatosensory evoked potentials. Threshold to electrical stimulation and two-point discrimination were obtained by the two-alternate forced choice technique.(ABSTRACT TRUNCATED AT 250 WORDS)     

Maxillary canine-lateral incisor transposition--orthodontic management

A case of maxillary canine-lateral incisor complete transposition is presented. Treatment options for transposed teeth, including alignment in their transposed positions, extraction of one or both transposed teeth, and orthodontic alignment to their normal positions in the arch, are discussed. The orthodontic technique and sequence used in this challenging case to align the fully transposed teeth to their normal position in the dental arch are described.