The purpose of this study was to evaluate the clinical performance of preformed beta-quartz glass-ceramic insert restorations.
Nine Class I and 30 Class II beta-quartz glass-ceramic insert restorations were placed in 16 patients who were seen regularly by personnel at Umeå University Dental School. The California Dental Association criteria were used to evaluate the restorations at baseline, 6 months, and 1, 2, and 3 years after luting. The occurrence of postoperative sensitivity, the time taken to manufacture each restoration, and certain periodontal conditions were also evaluated.
Sixty-nine percent of the restorations were rated satisfactory at the 3-year examination. During the follow-up period, 4 became loose and 7 were fractured or had flaking surfaces. Caries was registered in connection with 1 restoration. Excellent ratings were obtained for marginal integrity, anatomic form, surface, and color in 62%, 84%, 32%, and 44% of the restorations, respectively. There was no statistically significant difference in the occurrence of plaque and bleeding on probing in comparison with the controls. The mean overall time for placement was 38 minutes. The estimated survival rate (Kaplan-Meier) was 59% after 3.5 years.
The quality of the beta-quartz glass-ceramic restorations in the present study was inferior to that presented in most earlier studies of ceramic or resin composite posterior restorations placed in patients treated at university clinics. Both the technique and the beta-quartz glass-ceramic inserts have to be evaluated in more long-term studies to assess the possibility of their serving as an alternative restorative technique.
The objective of the study was to examine the coverage of the sealing program on first permanent molars (FPMs) and second permanent molars (SPMs) and first and second premolars (FSPMs), as well as to monitor the fate of the sealed teeth over time. All patients born in 1977 who had had regular check-ups in the Varkaus Health Center, Finland (n = 166) were included in the 1996 study. Data on the annual state of each tooth had been collected retrospectively since 1983. The coverage for the sealant program was 95%, 92%, and 6% of the FPMs, SPMs, and FSPMs, respectively. Out of the FPMs sealed at age 6 years, 28% were subjected to resealing, 13% developed occlusal, and 15% proximal caries during a 13-year follow-up period. From the SPMs sealed at age 11 years, 24% were subjected to resealing, 4% developed occlusal caries, and less than 2% proximal caries during the 9-year follow-up. None of the sealed FSPMs and only 1% of the non-sealed ones developed occlusal caries during the 9-year period. The mean DMF in the study population (n = 160) at age 12 years was 0.8 (n = 124), compared to a nation-wide mean value of 1.2. A large percentage of the FPMs and SPMs were sealed and then resealed during the study period. Although the study design lacked a control group for comparison, the lower caries rates of this study compared to the results of other studies with only a single application of sealants suggest a major role for resealing.
In 63 teenagers the proximal surfaces of premolars to be extracted for orthodontic reasons and the adjacent surfaces of neighboring teeth, 598 surfaces in all, were examined radiographically and by probing. Direct inspection after extraction revealed that 51% of the surfaces had incipient carious lesions and 5% lesions with cavities. Of the surfaces with cavities 82.1% were correctly diagnosed radiographically if any radiolucency, regardless of its extent, was used as a diagnostic criterion. However, this yielded a false positive rate of 19.6%. If only radiolucencies extending at least into the inner third of the enamel were called positive the true positive rate was 36.7% and the associated false positive rate 1.6%. At a 5% cavity frequency the predictive positive values were 17% and 53%, respectively. Probing yielded a true positive rate of about 29% and a false positive rate of 1.1% with a predictive positive value of 50-57%. All radiolucencies extending into the dentin were associated with cavities. When the most liberal radiographic criterion was used 37.5% of all carious lesions, whether associated with a cavity or not, were detected and 3.8% of sound surfaces were falsely called carious. The corresponding predictive positive value at the actual rate of incipient lesions and lesions with cavities was 92.6%.
Aspartic acid racemization analysis of a tooth from an Alaskan mummy yielded an age at death of 53 (+/- 5) years, which correlates well with earlier estimates based on morphological features. This study illustrates the value of integrative approaches to paleopathologic problems and the importance of preserving rare specimens for the application of new techniques.
From: Fortuine, Robert et al. 1993. The Health of the Inuit of North America: A Bibliography from the Earliest Times through 1990. University of Alaska Anchorage. Citation number 179.
OBJECTIVE: The purpose of this study was to describe agenesis of permanent teeth in children with respect to prevalence and intra-oral distribution according to gender. METHODS AND SUBJECTS: The study was population based and included all children in one district of the municipality of Aarhus, Denmark, in 1974-1979 (1657 girls and 1668 boys) and 1992-2002 (2409 girls and 2404 boys). The children underwent systematical clinical and radiographic examination. RESULTS: The period prevalence rates were almost identical for the two time periods (1972-1979: 7.8%; 1992-2002: 7.1%). Girls were affected more frequently than boys, and affected girls had more congenitally missing teeth than affected boys. Unilateral agenesis of the second premolars was more frequent than bilateral agenesis. In children with only one congenitally missing tooth, agenesis of the upper lateral incisors was asymmetrical in girls, but not in boys, whereas the opposite was true for the lower second premolars in boys. CONCLUSION: The prevalence of agenesis of permanent teeth in Danish schoolchildren seems to be constant over time, and similar to that found in other large, population-based studies. Intra-oral distributions of congenitally missing teeth indicate gender-specific patterns.
This article describes the long-term outcome of 40 consecutive patients having transplanted premolars. The objective of this ongoing study is to investigate survival rate, pulp survival rate, periodontal condition, and root development of autotransplanted premolars in orthodontic patients. This report covers 17 years; 32 orthodontic patients had 40 premolars transplanted into contralateral or opposing jaw quadrants where a premolar was missing. The teeth were examined systematically with clinical and radiographic measures at 1, 2, 6, 12, and 60 months or more after autotransplantation. The observation time varied from 2 years 5 months to 22 years 3 months, with a mean of 10 years 4 months. Bonded.018-in edgewise appliances were used, subjecting 87.5% of the transplanted teeth to normal orthodontic forces. One tooth was removed because of root fracture during the observation period, and 2 more had complications possibly related to the transplantation. The remaining 37 teeth and their supporting structures were all healthy at the last examination--a 92.5% success rate. Transplants with closed apices received endodontic therapy, but, in those with open or half-open apices, a 66% pulp survival rate was observed. No teeth in the sample had signs of replacement resorption or developed periodontal attachment loss. Inflammatory resorption in 2 teeth was arrested after endodontic treatment. Root formation, when not complete, continued on transplanted teeth, giving normal root form and adequate root length for normal function. It is concluded that autotransplantation of premolars combined with orthodontic treatment should be the first treatment alternative in cases of missing premolars, when a suitable donor tooth is available.
In individuals with simple hypodontia, congenital absence of teeth commonly affects just one tooth of a pair, not both. However, patterns of hypodontia have not been fully explored in children with Down syndrome (DS).
We describe the frequency and left-right symmetry of hypodontia in the permanent dentition of 8- to 9-year-old Norwegian children with DS.
This population-based cross-sectional study was part of a national prospective study evaluating upper airway function, hearing, dental, and craniofacial characteristics in a cohort of children with DS born in 2002. The cohort consisted of 29 children with DS and represented 57 per cent of all children born with DS in Norway in 2002. Hypodontia was assessed using panoramic and/or dental radiographs. Data were collected prospectively at TAKO-Centre, National Resource Centre for Oral Health in Rare Medical Conditions, Lovisenberg Diakonale Hospital, Oslo, Norway.
Hypodontia of permanent teeth, excluding third molars, was found in 61.5 per cent of the 26 children included in the final sample. Among the 16 children with hypodontia, 75.0 per cent were missing two or more permanent teeth. Two children (7.7 per cent) had severe hypodontia (oligodontia). The teeth most often missing were the maxillary lateral incisors, followed by the mandibular second premolars and maxillary second premolars. Most (68.9 per cent) cases of hypodontia occurred bilaterally.
The majority of the children with DS were missing one or more permanent teeth. Unlike in the general population, bilateral hypodontia was more common than unilateral hypodontia in this sample of children with DS.
The purpose of this brief communication is to report the results of an analysis of maxillary premolar accessory ridges (MxPAR), a common but understudied accessory ridge that may occur both mesial and distal to the central ridge of the buccal cusp of upper premolars. We developed a new five-grade scoring plaque to better categorize MxPAR variation. Subsequently, we conducted a population analysis of MxPAR frequency in 749 dental casts of South African Indian, American Chinese, Alaskan Eskimo, Tohono O'odham (Papago), Akimel O'odham (Pima), Solomon Islander, South African Bantu, and both American and South African Whites. Northeast Asian and Asian-derived populations exhibited the highest MxPAR frequencies while Indo-European samples (South African Indians, American and South African Whites) exhibited relatively low frequencies. The Solomon Islanders and South African Bantu samples exhibited intermediate frequencies. Our analysis indicates that statistically significant differences in MxPAR frequency exist between major geographic populations. As a result, the MxPAR plaque has now been added to the Arizona State University Dental Anthropology System, an important contribution as maxillary premolar traits are underrepresented in analyses of dental morphology.
To identify the times of emergence of the permanent teeth of Canadian Eskimos (Inuit), 368 children and adolescents were examined. The presence or absence of all permanent teeth except the third molars was recorded and these data subjected to probit analysis. Female emergence times were advanced over males. Generally, the Inuit of both sexes showed statistically significant earlier emergence times than Montreal children, except for the incisors. The present results do not support hypotheses indicating that premature extraction of the deciduous teeth advances the emergence of their succedaneous counterparts. There is some indication the controls of deciduous tooth emergence continue to play some part in emergence of the permanent dentition, especially the first permanent teeth that emerge.
From: Fortuine, Robert et al. 1993. The Health of the Inuit of North America: A Bibliography from the Earliest Times through 1990. University of Alaska Anchorage. Citation number 1263.
INTRODUCTION: The purpose of this study was to establish a method to prospectively predict the eruption of mandibular second premolars with panoramic radiographs. This technique could be used clinically to optimize the timing of comprehensive treatment, detect abnormalities of development and eruption, or effectively estimate eruption timing and determine the need for early intervention because of caries or defects of the deciduous dentition. METHODS: Three hundred one white children from an orthodontic practice in Alaska between the ages of 6 and 16 years were examined and monitored with serial panoramic radiographs until all premolars had erupted. Eruption of the mandibular second premolar was predicted at the first examination based on the panoramic radiograph. When the mandibular second premolar erupted, a researcher measured the crown length to crown-plus-root length ratio on the radiograph using the Simpson and Kunos scale, and the prospectively predicted timing of eruption was compared with the actual timing. RESULTS AND CONCLUSIONS: The Simpson and Kunos scale allowed a rapid assessment for predicting the time of eruption of mandibular second premolars. The mean age of eruption of the mandibular second premolar in these children was 12.5 years.