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Biomedical subjects

A Chosack

Publications and source records attributed to A Chosack.

At least 19 recordsLinked to original sources
PubMed1997

A histological and quantitative histomorphometric study of apexification of nonvital permanent incisors of vervet monkeys after repeated root filling with a calcium hydroxide paste.

The purpose of this study was to compare the effect of a monthly refilling of the root canals with calcium hydroxide paste with a single packing or replacement of the paste at 3 months on the apexification of nonvital maxillary incisors of vervet monkeys. Forty-eight maxillary incisors from 12 monkeys were used following radiographic determination that root development was incomplete. The pulps were extirpated under general anesthesia and the root canals filed and cleaned. The root canals were filled with a commercial calcium hydroxide paste, Calxyl, and a temporary cavity filling placed. Twelve teeth were left without further treatment. The calcium hydroxide paste was replaced in 12 teeth after a 3-month interval, and in the remaining 24 teeth the calcium hydroxide root filling was replaced five times at monthly intervals. The monkeys were killed after 6 months, and blocks of the teeth and surrounding tissues were embedded, decalcified and 6 microns serial sections prepared and stained. The sections were studied histologically to evaluate 11 parameters. Significant differences were found in the amount of calcium hydroxide at the apices, the presence of new cementum on the roots and the degree of inflammation, all of which were better in the monthly refill group. Histomorphometric measurements to evaluate the obturation of the open apices and the volume of new primary osteocementum showed no significant difference between the three groups. It was suggested that after the initial root filling with calcium hydroxide there was nothing to be gained by repeated root filling either monthly or after 3 months, for at least 6 months.

Analysis of Variance↗
PubMed1994

Dental caries and social factors in 12-year-old South African children.

Dental caries prevalence (percentage caries-free) and experience (DMFS) were recorded, in 414 12-yr-old Indian and 401 white children living in adjacent urban communities with the same fluoride concentration in the drinking water (0.21-0.33 ppm) using WHO (11) criteria. Details of social factors: education level, family income, home space and occupants and parental occupation were obtained by questionnaire. Dental caries was significantly worse in the Indian children with regard to numbers caries-free (30%--white and 40%--Indian) and DMFS mean (sd) (3.65 (3.98) and 2.66 (3.49) working group, respectively). Social class, white or blue collar, family income and room to person ratio were significantly associated with dental caries in the white children but there were no significant associations in the Indian children. Multiple regression analysis showed race and sex to be significant factors.

Chi-Square Distribution↗
PubMed1991

Dental caries experience of 5-year-old children related to their parents' education levels: a study in an Arab community in Israel.

The purpose of this study was to examine the influence that parents' education may have on the prevalence of dental caries in young children. The study was conducted on 210 kindergarten children aged 5 years in an Arab village. The presence of caries was determined according to the WHO criteria, with an explorer and a dental mirror under natural light. The education of the parents was assessed on a scale of 1-6 according to information obtained from a questionnaire to the parents. The results of this study showed that children of highly educated parents had relatively low dental caries experience. The influence of the mothers was apparent at a lower educational level than that of the fathers. In this population only 0.6% of the dental treatment needs were met. Of the kindergarten children 99.5% had experienced caries. The caries experience was extremely high: the mean dmfs was 17.7 (+/- 12.15), and the means dmft 8.04 (+/- 8.37).

Analysis of Variance↗
PubMed1990

Social class, parents' education and dental caries in 3- to 5-year-old children.

The caries prevalence of 1273-, 4- and 5-y-old white children was determined with mirror and probe under natural light at mother and child clinics. The social class of the family, the educational level of the mother and that of the father were determined from a questionnaire filled in by the accompanying adult at the time of examination. Both social class and parent's education had a statistically significant influence on the caries prevalence: those in the lower social classes and with parents without tertiary education had a much higher prevalence of caries.

Child, Preschool↗
PubMed1990

Assessment of marginal leakage around Class II composite restorations in retrieved primary molars.

The aim of the present investigation was to evaluate, by means of dye penetration, the microleakage around Class II composite restorations, in retrieved primary molars that functioned in the mouth for at least one year. The experimental material consisted of 13 exfoliated primary molars that had been restored with Herculite (Kerr Corporation, Romulus, Michigan 48174 USA) at least one year previously, utilizing an incremental or a bulk filling technique. The retrieved teeth were insulated with utility wax and nail polish, immersed in 2% basic fuchsin, embedded in acrylic resin, and ground off to various depths. The marginal leakage was assessed according the degree of dye penetration at the occlusal and cervical margins. No difference was observed between the two filling techniques. In most teeth, no leakage at the occlusal margins was observed; minimal leakage, limited to the enamel, was observed at the occlusal margins of two teeth, one of each filling technique. Severe penetration was evident at the cervical margin of three restorations, two of them filled incrementally and the third using the bulk technique. Mild to moderate penetration was observed at the cervical margin in the majority of the other restorations. It was concluded that an incremental filling technique could not eliminate microleakage at the cervical margins of Class II composite restorations.

Child↗
PubMed1989

A clinical, radiographic, and SEM evaluation of Class 2 composite restorations in primary teeth.

Sixty class 2 composite resin restorations were placed in 22 children and evaluated at baseline, six months, and one year. Radiographs were used for evaluation, in addition to clinical examinations, photographs, and scanning electron micrographs of epoxy resin casts of retrieved teeth. It was concluded that radiographs are necessary to detect a large percentage of failures at the gingival margins of class 2 composites.

Child↗
PubMed1988

Caries prevalence and severity in the primary dentition and Streptococcus mutans levels in the saliva of preschoolchildren in South Africa.

The caries prevalence (dmft) and severity (css) in 3-, 4-, and 5-yr-old children in South Africa were examined. Four levels of S. mutans in the saliva of 228 of these children was estimated by the spatula method. In all three age groups a statistically higher dmft and css was found with a S. mutans level of greater than 10(6) CFU/ml in saliva than at lower concentrations. At age 5 ANOVA showed significant differences between dmft and css at all S. mutans levels. A high concentration of S. mutans in the saliva may be an indicator of the high risk child at an early age.

Child, Preschool↗
PubMed1987

Autopolymerized versus light-polymerized fissure sealant.

This study found that 31 months after placement of a sealant, no significant difference was seen in the clinical performance and retention between the visible light-polymerized and autopolymerized materials. Practitioners can use either material without compromising efficacy.

Chemical Phenomena↗
PubMed1986

A dental caries severity index for primary teeth.

Criteria for scoring the caries attack on each surface of an affected primary tooth are described. The score for each carious surface ranges from 1 to 3. The score per tooth is a sum of the surface scores. The caries severity index (csi) is the mean of the scores of all carious teeth in the population examined. Three groups of children aged 5-6.5 yr were examined. In Jerusalem, with a water fluoride concentration of 0.4 ppm, 54 children had a csi of 2.99 and a defs of 10.19. In a semirural African town, Soshanguva, with a 0.2 ppm fluoride concentration, 103 children had a csi of 3.10 and a defs of 5.75. In a nearby rural African area with a water fluoride concentration well above the optimum, 86 children had a csi of 1.93 and a defs of 1.99. Interexaminer and intraexaminer reproducibility of the csi were good. The csi expresses the severity of the caries attack on affected teeth and gives additional information to that of the def indices.

Child↗
PubMed1985

Occlusal composite restorations: 4-year results.

A study was performed to determine the success of a conservative cavity preparation using the principle of sealing for prevention rather than cavity extension for prevention. A total of 332 restorations were placed in 240 teeth of 110 subjects, aged 6 to 14, with a mean age of 8 years. After 4 years, 205 restorations were examined. Caries appeared in 13 teeth and sealant wear occurred in 14 restorations. Complete sealant loss was observed in eight restorations and partial loss in 38, leaving 156 restorations with complete retention of the sealant. These preliminary results show that conservative cavity preparation with sealing for prevention is a successful technique that conserves valuable tooth structure.

Adolescent↗