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PubMedDate not supplied

Influence of examiner's clinical experience in detecting occlusal caries lesions in primary teeth.

PURPOSE: The purpose of this study was to evaluate the effect of examiner's clinical experience in detecting occlusal caries lesions in primary teeth using visual inspection and the diode laser fluorescence (LF) method. METHODS: Eighty-seven suspected occlusal sites in 50 exfoliated or extracted primary molars were evaluated via the visual inspection and LF (DIAGNOdent) by 3 last-year dental students, 3 recent graduate dentists, and 3 pediatric dentistry specialists. After the examination, the teeth were cut and evaluated in stereomicroscope. Sensitivity, specificity, and accuracy were calculated, and the values were compared using the McNemar change test at the enamel and dentin caries lesion thresholds. The means of Cohen's kappa values among the different groups of examiners were compared with the ANOVA and Student-Newman-Keuls test. RESULTS: At the enamel caries lesions threshold, there was no difference in accuracy among the different groups of examiners using both the methods. At the dentin caries threshold, however, the students achieved the worst results using visual inspection. Nevertheless, regarding visual inspection, the dental students presented higher sensitivity and lower specificity than the other examiner groups at both thresholds. When using the LF method, there was no significant difference among the parameters, and the interexaminer agreement was higher. CONCLUSIONS: Detecting caries lesions with the laser fluorescence device presents lower variation with respect to the examiner's experience.

Analysis of Variance↗
PubMed2002

Reliability of different techniques to assess marginal defects of Class II restorations in retrieved primary molars: a visual-tactile, SEM, dye penetration and polarized light microscopy study.

The aims of the present article were to assess the reliability of different techniques to assess marginal defects in Class II restorations in retrieved primary molars, and to determine the degree of agreement between the various assessment modalities. The material evaluated was comprised of 18 exfoliated primary molars that had been restored 20 to 22 months previously with a resin-modified glass ionomer (Vitremer--7 teeth), a hybridized composite resin (Z100 + Scotchbond Multipurpose--9 teeth), and amalgam (Dispersalloy--2 teeth). No significant differences could be observed between the groups. The majority of the restorations rated A at the buccal and lingual margins, but poor adaptation was disclosed at the cervical margin of the three types of restorations. SEM evaluation revealed that the highest percentage of defects was seen at the cervical margins with no statistically significant difference between the groups. No or minimal leakage was present at the occlusal margins and severe penetration of dye was seen at the cervical margins in all groups. Significantly less demineralization was seen adjacent to the Vitremer and Z100 restorations when compared to the Dispersalloy but no difference was found between the esthetic restorations. Except for the visual tactile examination, small marginal defects could be disclosed by the three assessment techniques (SEM, dye penetration, and polarized light microscopy). A good degree of agreement was observed between the three evaluation techniques.

Child↗
PubMed2004

Craniofacial morphology and growth in the ferret: effects from alteration of masticatory function.

INTRODUCTION: Our hypothesis is that any effects on craniofacial growth and morphology induced by altering the masticatory function will vary according to the species involved. The general aim of this thesis was to test the possible effects of altering the masticatory function on craniofacial growth and morphology, as well as features of masticatory muscles in ferrets. To better elucidate these mechanisms involved, the anatomy of the skull, craniofacial growth pattern and development of occlusion in the ferret were investigated to serve as baseline data. MATERIALS AND METHODS: The description of the anatomy and the radiographic features of the skull was based on observations of 100 skulls of adult ferrets of both sexes. The craniofacial growth pattern was studied in 16 young ferrets of both sexes using serial cephalograms taken on 5 occasions according to age: 25 days, 35 days, 55 days, 80 days and 300 days. To follow the development of occlusion, these animals underwent dental examinations every other day. Forty male ferrets were divided into two groups from the age of 5 weeks. One group was fed hard pellets (hard-diet group), and the other the same diet but softened with water (soft-diet group). After six months, specimens of masticatory muscles were dissected and analysed histochemically, and cephalograms were analysed cephalometrically. RESULTS: The ferret skull is relatively elongated with a short facial region, being longer and broader in males than in females. The viscero- and neurocranium follow an orderly pattern of expansive growth. The growth of the mandible is mainly characterized by an anteroposterior body elongation, and enlargement of the coronoid process. Craniofacial growth in ferrets ceases earlier in female than in male animals. The deciduous teeth erupted between the 19th and 31st postnatal day, and exfoliated approximately between days 51 and 76. The time of eruption of the permanent teeth ranged from 42 to 77 days. The female ferrets were generally ahead of the males regarding the eruption age of permanent teeth. The alteration of the masticatory function by feeding the animals a soft diet caused a hard palate plane more distant from the cranial base plane, smaller inter-frontal and inter-parietal widths, and a slenderer zygomatic arch, as well as a generally shorter and narrower coronoid process. Variations of most variables are greater in animals fed on soft diet. The mean cross-sectional area of type I and type II fibres in the temporalis and the masseter, and type II fibres in the digastricus, as well as the number of capillaries per fibre were significantly smaller in the soft-diet animals. CONCLUSION: Altered masticatory function has induced changes in masticatory muscles and certain effects on craniofacial growth in ferrets. These changes are not the same as those reported in other species (e.g. rats). It appears that reduced masticatory function leads to smaller fibres in the elevators and transverse skull dimensions. The different effects are presumably related to the differences in craniofacial anatomy and growth pattern, as well as the masticatory system, in the various species studied previously.

Animals↗
PubMed1999

Marginal adaptation of compomers in Class I and V cavities in primary molars.

PURPOSES: To evaluate in primary molars (1) the adaptation of three compomers in Class I and V cavities at the cavosurface margins and inside the cavity, and (2) the effect of cavity etching on such adaptation. MATERIALS AND METHODS: The three compomers used were Compoglass, Dyract and Hytac. Sixty exfoliated primary molars were divided for the three compomers, which were subdivided into Class I and V (10 each) and subdivided again into etched and non-etched (5 each). Standard Class I and Class V cavities with the gingival margins at cementum were prepared. The cavities were restored with the three compomers used with or without etching the cavity. The restored cavities were finished and polished. The cavosurface margins were inspected under the light microscope. Then the restored teeth were sectioned into two halves. The cut halves were fixed in glutaraldehyde and the cut surfaces smoothed, polished and inspected under the light microscope for adaptation of the restorative material inside the cavities. One halve of each molar was prepared for SEM. RESULTS: The three compomers showed good adaptation at the cavosurface margin except the non-etched Class V cavities restored with Dyract. Compoglass and Dyract were well adapted inside the cavity better than Hytac. Cavity angles were common sites for adhesive pooling for all materials. SEM examination showed good adaptation of the restorative at enamel and cementum interface especially in etched cavities. The dentin-restorative interface showed consistent hybrid layer with resin tags in the etched cavities. However this layer was inconsistent in the non-etched cavities.

Acid Etching, Dental↗
PubMed1998

Interfacial adaptation of in vivo aged polyacid-modified resin composite (compomer) restorations in primary molars. A SEM evaluation.

Polyacid-modified resin composite (PMC) restorations are being increasingly used in class II cavities in primary teeth. The aim of this study was to evaluate the interfacial adaptation of 1-month- and 30-month-old in vivo restorations by quantitative scanning electron microscopy (SEM) evaluation. Twelve PMC restorations were performed under clinically controlled conditions in primary molars planned for extraction 1 month later for orthodontic reasons. Eleven other PMC restorations, aged 30 months (range 1.5-3 years) and part of a multicenter study, were collected after exfoliation. To observe the interfacial adaptation of each restoration at several levels a thin layer of the proximal surface was ground off 2-3 times. Replica impressions of each level were prepared for SEM. The interfaces of the replicas were evaluated at x200 and x1000. In the 1-month-old restorations gap-free adaptation to enamel was found in 87% and to dentin in 84% of the total interfacial length investigated. For the 30-month-old restorations gap-free adaptation was registered in 59 and 63%, respectively. The interfacial quality was significantly better in the 1-month-old restorations than in those 30 months of age. Adaptation to enamel was significantly better in the cervical part of the 1-month-old restorations than in the axial walls, whereas there was no significant difference in dentin. No significant difference was found between the cervical and axial cavity walls of the 30-month-old restorations. Enamel fractures were registered in 31 and 24%, respectively of the interfacial length of the 1-month- and 30-month-old restorations. The corresponding findings in dentin were 0 and 0.9%. It can be concluded that restorations aged for a short time showed a high percentage of sealing, which decreased significantly for the 30-month-old ones.

Analysis of Variance↗
PubMedDate not supplied

Microleakage of adhesive resin systems in the primary and permanent dentitions.

PURPOSE: The purpose of this study was to compare the in vitro microleakage of fourth-generation filled and unfilled adhesive resin systems with fifth-generation filled and unfilled adhesive resin systems in both primary and permanent teeth. METHODS: Eighty extracted or exfoliated human noncarious teeth (40 primary and 40 permanent) were assigned to each of 8 groups. Groups 1, 3, 5 and 7 were primary teeth, and groups 2, 4, 6 and 8 contained permanent teeth. Groups 1 and 2 were bonded with Optibond Fl (Kerr), groups 3 and 4 with Scotchbond Multipurpose (3M), groups 5 and 6 with Optibond Solo Plus (Kerr) and groups 7 and 8 with Single Bond (3M). All teeth received a Class V cavity preparation, and the cavosurface margins were placed entirely in enamel. They were then restored with TPH Spectrum Shade Al (Dentsply Caulk). All teeth were thermocycled, stained with basic fuchsin, sectioned and viewed under the microscope. Measurements were recorded in absolute millimeters and relative grades as judged by 2 evaluators. RESULTS: No significant difference in microleakage was observed between fourth- and fifth-generation adhesive resin systems, whether filled or unfilled, or applied on primary or permanent teeth. Significant differences were found in the amount of microleakage at the gingival and occlusal surfaces in all groups. One-bottle, fifth-generation adhesive resin systems permit easier application with the same effectives as the 2-bottle, fourth-generation systems. CONCLUSIONS: One-bottle, fifth-generation adhesive resin systems permit easier application with the same effectiveness as the 2-bottle, fourth-gerenration systems.

Adhesives↗
PubMedDate not supplied

Antecedents and correlates of hypoplastic enamel defects of primary incisors.

Four hundred and fifty-five exfoliated primary incisors were obtained from children whose mothers provided information about a wide range of pre-, peri-, and postnatal characteristics of both the mother and child. These teeth then were examined for the presence of hypoplastic enamel defects (HED). The basic form of the null hypothesis tested was that children who had HED of a primary incisor did not differ from those who did not have such a defect. Of the primary incisors examined, 18.5% had HED (25.0% maxillary and 10.1% mandibular). The following items were found to be associated most strongly (P less than 0.003) with an increase in a child's risk of developing HED; 1) maternal antenatal history of smoking, higher prepregnancy weight, and failure to obtain prenatal care during the first trimester; 2) prematurity, low birth-weight and their associated correlates; and 3) postnatal measles infection. Left-handedness, maternal tea and Tylenol (McNeil Consumer Products Co., Fort Washington, PA) consumption, and failure to screen for undue lead burden were associated less prominently (P less than 0.05) with HED prevalence. Season of birth and serum and dentin lead levels were not related to the prevalence of HED. Many of these risk factors are also covariates of low socioeconomic status such as suboptimal nutrition and increased risk of infection. Additional investigation is needed to delineate the associations between specific pre- and perinatal nutritional and infectious factors, socioeconomic status, and HED development.

Child, Preschool↗