Utilization of dental services by first-year Students, The University of Sydney, 1978

A bstract — A stratified sample of 1,588 of the 3,990 first year students at The University of Sydney responded to a questionnaire on the utilization of dental services as set out in the World Health Organization's Combined Oral Health and Treatment Assessment Form. More than 70 per cent had obtained dental care within the previous 12 months and 59 per cent of these visited for a check-up. The most common reasons for not obtaining dental care was given as "nothing wrong, or there was no reason for going". Sixty-five per cent indicated that they considered there was nothing wrong with their teeth, gums, or mouth. Twenty-five per cent wanted advice or treatment mostly for examination or cleaning. Comparison of results was made between Faculties and other community studies.     

The use of arthrography in management of temporomandibular joint problems

A bstract — Arthrography is useful in selecting those patients with severe dysfunction of the temporomandibular joint who would benefit from surgery. Plain films are usually unrewarding in the diagnosis of soft tissue abnormalities of the joint. Three cases are presented, illustrating the most common problems encountered and diagnosed by arthrography.     

Caries in children and quality of life

Caries is the most prevalent oral disease in children. The majority of caries in toddlers remains untreated, with toothaches as a consequence. Although toothache is an important determinant of the quality of life, prevalence data on toothaches hardly exist. Research results indicate that children's quality of life improves after caries treatment. The question remains which type of treatment is preferable. To address this question, evidence from randomized controlled clinical trials on various treatment methods is needed.     

A hidden periodontitis epidemic during the 20th century?

OBJECTIVES: Increasing evidence suggests a strong causal link between smoking and periodontitis. The goal of this study was to impute how the secular changes in smoking prevalence during the 20th century impacted the advanced periodontitis incidence in the US. METHODS: Epidemiological analyses based on US prevalence data of advanced periodontitis and smoking, and predictions of future smoking prevalence. RESULTS: Assuming other risk factors for periodontitis remained constant, we estimated that the incidence of advanced periodontitis decreased by 31% between 1955 and 2000. The changes in smoking habits, and consequently the changes in periodontitis incidence, depended strongly on education and gender. Between 1966 and 1998, we estimated a 43% decreased periodontitis incidence among college-educated individuals versus only an 8% decrease among individuals with less than a high school education. Between 1955 and 1999, we estimated a 41% decrease among males versus a 14% decrease among females. By the year 2020, the incidence of advanced periodontitis may decrease 43% from its level in 1955. CONCLUSIONS: A periodontitis epidemic fueled by smoking remained hidden for most of the 20th century. Because this epidemic was hidden, it distorted our understanding of the treatment and etiology of periodontitis. The socioeconomic polarization of this epidemic will dictate alterations in patterns of periodontal care.     

Actinomyces spp. in supragingival plaque of ethnic Chinese preschool children with and without active dental caries

Very limited molecular epidemiological data are available on the role of Actinomyces spp. in the pathogenesis of caries in the primary dentition. Therefore, we investigated their distribution in supragingival plaque of ethnic Chinese preschool children from Singapore and Hong Kong, either with or without active caries. Plaque samples were taken from intact interproximal enamel areas using dental floss. Bacterial genomic DNA of each sample was extracted and variable regions of 16S ribosomal DNA amplified and labelled with digoxigenin. Oligonucleotide probes specific for Actinomyces bovis, Actinomyces gerencseriae, Actinomyces israelii, Actinomyces meyeri, Actinomyces odontolyticus, catalase-negative Actinomyces naeslundii (genospecies 1 and 2) and catalase-positive Actinomyces naeslundii genospecies 2 (previously Actinomyces viscosus serotype II) were used to detect these species using Southern hybridization with a Minislot and Miniblotter system. A. odontolyticus, A. gerencseriae and A. meyeri were detected with similar frequency in both Singapore and Hong Kong samples or in those with and without active caries. However, the prevalence of A. naeslundii was significantly different in the two locales (p<0.05). A. odontolyticus (88.7%), A. gerencseriae (56.6%) and A. naeslundii (50.9%) were detected in a majority of the samples and the positive hybridization signals of A. gerencseriae in the caries-active group were stronger than from the caries-free group. A. bovis and A. israelii were undetectable in any of the samples. These data imply that A. odontolyticus, A. naeslundii and A. gerencseriae may play an important role in supragingival plaque formation on primary teeth in ethnic Chinese, with others such as A. meyeri contributing.     

Adverse reactions associated with the use of eugenol in dentistry

Eugenol is a material commonly used in dentistry with few reported side effects. It is not however, a bio-friendly material when in contact with oral soft tissues. It can produce both local irritative and cytotoxic effects, as well as hypersensitivity reactions. Here we report on two cases of adverse local reaction to eugenol, contained within a temporary restorative material and a temporary cementation material respectively, which illustrate these problems.     

Wear behavior of new composite restoratives

This study investigated the wear resistance of recently introduced nanofill (Filtek Supreme [FS], 3M-ESPE) and ormocer (Admira [AM], Voco) composites and compared their wear characteristics to microfill (Filtek A110 [AO], 3M-ESPE]), minifill (Esthet X [EX], Dentsply; Filtek Z250 [ZT], 3M-ESPE) and polyacid-modified (Dyract AP [DY], Dentsply) composites. Six specimens were made for each material. The specimens were conditioned for one week in distilled water at 37 degrees C and subjected to wear testing at 20 MPa contact stress against SS304 counter-bodies using reciprocal compression-sliding wear instrumentation. Distilled water was used as lubricant. Wear depth (microm) was measured using profilometry every 5,000 cycles up to 20,000 cycles. The results were analyzed using ANOVA/Scheffe's test (p<0.05). Wear of the materials was cycle and fatigue dependent. Although no significance in wear was observed between materials after 5,000 cycles of wear testing, significant differences were observed at 10,000 cycles and greater. After 20,000 cycles of wear testing, ranking was as follows: ZT > DY >AM > AO > FS > EX. Wear ranged from 39.90 microm for EX to 113.32 microm for ZT. The wear resistance of ZT and DY was significantly lower than AO, FS and EX In addition, ZT experienced significantly more wear than AM. Under the conditions of this in-vitro study, the wear resistance of nanofill and ormocer composites was comparable or superior to polyacid-modified, microfill and minifill composites.     

Phenotypes, serotypes and antibiotic susceptibility of Swedish Porphyromonas gingivalis isolates from periodontitis and periodontal abscesses

This study was conducted to reveal phenotypic, serological subtypes and antibiotic susceptibility among fresh isolates of Porphyromonas gingivalis in a Swedish population with periodontitis and periodontal abscess. Fifty-five subgingival strains were isolated and tentatively designated as P. gingivalis from 55 consecutive paper-point samples taken from 51 patients with periodontitis (at least one site with >6-mm pocket depth) in Sweden and were sent in for microbiological evaluation. Eight P. gingivalis strains from periodontal abscesses were also included. Four P. gingivalis strains served as reference and another four type strains were included. The strains were characterized by colony morphology, biochemical tests, enzyme profile, gas-liquid chromatography and antibiotic susceptibility. The strains were further characterized for whole cell protein profiles using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and were identified to serotype by specific monoclonal antibodies. Among the 55 P. gingivalis strains 35 had smooth (S), 13 rough (R) and seven semi-rough colony morphologies. All strains were phenotypically homogeneous in biochemical tests, enzyme profile and antibiotic susceptibility. All strains produced phenylacetic acid and alpha-fucosidase. Almost all (96%) of the subgingival strains, but relatively fewer (62%) of the abscess strains, belonged to serotype A. Two subgingival and three abscess strains were classified as serotype B. No specific SDS-PAGE protein profiles were recorded for the two serotypes. The P. gingivalis strains from Swedish periodontitis cases showed homogeneity in terms of biochemical phenotypes and antibiotic susceptibility patterns. The strains fell into two serotypes, of which serotype A predominated in the periodontitis cases and serotype B was overrepresented in periodontal abscesses.