Assessment of the effectiveness of dental sterilizers using biological monitors.

This study was undertaken to evaluate the effectiveness of steam, chemical vapor, and dry heat sterilizers, over a three-year period, in dental operatories subscribing to the University of British Columbia's sterilization monitoring service. A total of 4,579 sterilizer loads were tested. The results demonstrated an overall failure rate of 4.4 per cent. Individual failure rates for each type of sterilizer were: chemiclaves, 4.9 per cent; steam autoclaves, 2.3 per cent; and dry heat ovens, 7.9 per cent. In 38 per cent of these cases, the reasons for failure could be attributed to a definite cause.     

Clinical and biological indicators of dental caries and periodontal disease in adolescents with or without obesity

Objective

This study aims to assess clinical, microbiological and inflammatory parameters as indicators for caries and periodontal disease in adolescents with obesity.

Material and methods

Twenty-seven adolescents with obesity [body mass index (BMI) 37?±?4 kg/m²] and 28 controls (BMI 20?±?2 kg/m²) answered questionnaires and were investigated regarding salivary parameters, plaque pH drop after a 1-min glucose rinse, oral clinical parameters, inflammatory markers in gingival crevicular fluid (GCF) and sub-gingival mirobiota.

Results

Compared with controls, adolescents with obesity had a lower stimulated salivary secretion rate (1.55?±?0.63 vs. 2.05?±?1.05 mL/min, p?<?0.05), higher concentrations of secretory immunoglobulin A (sIgA) (p?<?0.001), more decayed tooth surfaces (3.4?±?6.6 vs. 0.8?±?1.1, p?<?0.05) and more gingivitis (p?<?0.01) after controlling for possible confounders. Overall, similar snacking habits, plaque amounts and numbers of deep periodontal pockets were observed. Following the glucose rinse, a slightly more pronounced drop in plaque pH was observed in the obesity group (p?>?0.05). No differences in sub-gingival inflammatory or microbial indicators were detected (p?>?0.01).

Conclusions

More caries and gingival inflammation were observed in adolescents with obesity. Of the indicators tested, salivary secretion rate was lower and sIgA levels were higher in the obesity group. We are unable to confirm whether differences in caries and gingival inflammation are due to systemic changes that are associated with obesity or due to possible irregular dietary/oral hygiene habits.

Clinical relevance

Customised oral health preventive programmes and appropriate collaboration with medical personnel in selecting the best diet, medication and psychological support can help improve the general well-being, including oral health, of children with obesity. This may even reduce the risk of oral diseases.     

Improving dental health status indicators for evaluation

Abstract Central to the evaluation of any dental health programme is the dental status of the population it serves. The DMFT index has been widely used to indicate dental status in evaluations, however, there are a number of characteristics of the DMFT index which undermine its value in evaluating programmes. The aim of this study was to compare DMFT, live utility weighted versions of this index, and single measures of caries experience, in order to determine their relative validity. The indices were investigated in terms of two criteria: 1) the percentage of variance explained by a set of antecedent and behavioural variables in a series of multiple regression analyses; and 2) percentage changes in the indices following re-examination of the population after live years. Results show that the variance explained by the different composite indices ranged between 29% and 46%, while it varied between 16% and 49% for the single measures. The size of percentage changes after five years ranged between 0% and 4.5%, and indicated that utility weighted indices were generally not more sensitive than the DMFT, but that some single measures were. Where composite indices are required, a lull quality adjusted tooth years (QATY) approach, rather than utility weighting the DMFT index, may be required to improve the validity of dental health status indicators. Single rather than composite measures also provide valid information for evaluating dental programmes.     

Social indicators of dental caries among Sierra Leonean schoolchildren

Most of the caries of African child populations is found in limited fractions of that population. The purpose of the present study was to analyze the caries situation of Sierra Leonean schoolchildren in relation to demographic, socioeconomic, and behavioral variables, in order to develop an appropriate index for prediction of caries. A total of 610 students from primary class 1 (mean age: 7 yr) and secondary form 1 (mean age 15 yr) were dentally examined by three examiners and interviewed by their teachers. Intra- and interexaminer reproducibilities were 82 and 70%, and interinterviewer reliability was 67–100% for the individual questions. Urban students had more caries than rural. In class 1, dmfs + DMFS was 4.1 and 1.8, respectively; in form 1, DMFS was 5.3 and 3.5. Two tribes (the Fulas and the Madingos) had higher caries means than the rest, especially in class 1, where dmfs + DMFS was 6.5 and 2.4, respectively. Form 1 students with literate parents had a higher caries mean, and class 1 pupils with defective school uniforms a lower mean. The apparently high-risk groups did not consume more sweet snacks or clean their teeth less frequently. There was clearly more caries among the quartiles of children with most visible plaque on molars, but all social and demographic subgroups had similar amounts of plaque. Multivariate analyses of class 1 children showed that pupils living in urban areas, Fulas and Madingos, and children wearing complete school uniforms had caries significantly more frequently, other factors being equal. In form 1, urban students, rural Fulas and Madingos, students with literate parents, and urban students consuming sweet snacks frequently had significantly more caries. Social criteria were sufficient to identify rural children with high caries experience, but insufficient in urban areas.     

Bonding effectiveness to different chemically pre-treated dental zirconia

Objective

The objective of this study was to evaluate the effect of different chemical pre-treatments on the bond durability to dental zirconia.

Methods

Fully sintered IPS e.max ZirCAD (Ivoclar Vivadent) blocks were subjected to tribochemical silica sandblasting (CoJet, 3M ESPE). The zirconia samples were additionally pre-treated using one of four zirconia primers/adhesives (Clearfil Ceramic Primer, Kuraray Noritake; Monobond Plus, Ivoclar Vivadent; Scotchbond Universal, 3M ESPE; Z-PRIME Plus, Bisco). Finally, two identically pre-treated zirconia blocks were bonded together using composite cement (RelyX Ultimate, 3M ESPE). The specimens were trimmed at the interface to a cylindrical hourglass and stored in distilled water (7 days, 37 °C), after which they were randomly tested as is or subjected to mechanical ageing involving cyclic tensile stress (10 N, 10 Hz, 10,000 cycles). Subsequently, the micro-tensile bond strength was determined, and SEM fractographic analysis performed.

Results

Weibull analysis revealed the highest Weibull scale and shape parameters for the ‘Clearfil Ceramic Primer/mechanical ageing’ combination. Chemical pre-treatment of CoJet (3M ESPE) sandblasted zirconia using Clearfil Ceramic Primer (Kuraray Noritake) and Monobond Plus (Ivoclar Vivadent) revealed a significantly higher bond strength than when Scotchbond Universal (3M ESPE) and Z-PRIME Plus (Bisco) were used. After ageing, Clearfil Ceramic Primer (Kuraray Noritake) revealed the most stable bond durability.

Conclusion

Combined mechanical/chemical pre-treatment, the latter with either Clearfil Ceramic Primer (Kuraray Noritake) or Monobond Plus (Ivoclar Vivadent), resulted in the most durable bond to zirconia.

Clinical relevance

As a standard procedure to durably bond zirconia to tooth tissue, the application of a combined 10-methacryloyloxydecyl dihydrogen phosphate/silane ceramic primer to zirconia is clinically highly recommended.     

Water fluoridation: current effectiveness and dental fluorosis

Abstract – This paper reviewed the literature on the evidence for water fluoridation's effectiveness under current conditions of multiple fluoride use at recommended and at reduced concentrations, the extent of dental fluorosis at different fluoride concentrations, and the "halo" effect of water fluoridation. Using the relative difference in dental caries between communities with low and optimal water fluoride as an indicator, the effectiveness of water fluoridation has decreased over time as the use of other fluorides has increased. Thus the effectiveness of water fluoridation alone cannot now be determined. Compared to the early fluoridation studies, the differences in dental caries and fluorosis prevalence between fluoridated and non-fluoridated areas have markedly narrowed. Both the prevalence and severity of dental fluorosis have increased since 1945; however, the portion of fluorosis due to water fluoridation is now less (40%) than that attributed to other fluoride sources (60%). Research also suggests that the "halo" effect of community water fluoridation may result in a significantly greater intake of fluoride for people in non-fluoridated communities. This review recognized that since water fluoridation has unique advantages from the perspectives of distribution, equity, compliance and cost-effectiveness over other fluoride technologies, it remains as the fundamental base for caries prevention. The increasingly greater contribution that other sources of fluoride make to dental fluorosis suggests that these sources of fluoride, many of which arc used on an elective basis, should be more closely examined for needed changes.     

Predicting clinical biological responses to dental materials

Objectives

Methods used to measure and predict clinical biological responses to dental materials remain controversial, confusing, and to some extent, unsuccessful. The current paper reviews significant issues surrounding how we assess the biological safety of materials, with a historical summary and critical look at the biocompatibility literature. The review frames these issues from a U.S. perspective to some degree, but emphasizes their global nature and universal importance.

Methods

The PubMed database and information from the U.S. Food and Drug Administration, International Standards Organization, and American National Standards Institute were searched for prominent literature addressing the definition of biocompatibility, types of biological tests employed, regulatory and standardization issues, and how biological tests are used together to establish the biological safety of materials. The search encompassed articles published in English from approximately 1965-2011. The review does not comprehensively review the literature, but highlights significant issues that confront the field.

Results

Years ago, tests for biological safety sought to establish material inertness as the measure of safety, a criterion that is now deemed naive; the definition of biocompatibility has broadened along with the roles for materials in patient oral health care. Controversies persist about how in vitro or animal tests should be used to evaluate the biological safety of materials for clinical use. Controlled clinical trials remain the single best measure of the clinical response to materials, but even these tests have significant limitations and are less useful to identify mechanisms that shape material performance. Practice-based research networks and practitioner databases are emerging as important supplements to controlled clinical trials, but their final utility remains to be determined.

Significance

Today we ask materials to play increasingly sophisticated structural and therapeutic roles in patient treatment. To accommodate these roles, strategies to assess, predict, and monitor material safety need to evolve. This evolution will be driven not only by researchers and manufacturers, but also by patients and practitioners, who want to use novel materials in new ways to treat oral disease.     

Assessing risk indicators for dental caries in the primary dentition

The aim of the present study was to assess indicators shown to be associated with the prevalence of caries in the primary dentition of 7-year-old Flemish schoolchildren. Cross-sectional first year data of the longitudinal Signal-Tandmobiel survey were analysed (n=4468). Gender, age, oral hygiene habits, use of fluorides, dietary habits, geographical factors and parental modelling were the considered predictors. From the multiple logistic regression analysis, including schools as a random effect, and after adjusting for the confounding variables-educational system and province (stratification variables), gender and age-it became clear that the following risk indicators remained significant (at 5% level) for the presence of caries: frequency of toothbrushing (P=0.05) with an OR 1.24 for brushing less than once a day, age at start of brushing (P<0.001) with an OR=1.22 for a delay of 1 year, regular use of fluoride supplements (P<0.001) with an OR=1.54 for no use, daily use of sugar-containing drinks between meals (P<0.001) with an OR=1.38, and number of between-meals snacks (P=0.012) with an OR=1.22 for using more than 2 between-meal snacks. There was a significant difference (P<0.05) in caries experience determined by the geographical spread, with an explicit trend of caries declining from the east to the west. In a model with an ordinal response outcome, the daily use of sugar-containing drinks between meals had a more pronounced effect when caries levels were high. From this study it became obvious that, in Flemish children, an early start of brushing and a brushing frequency of at least once a day need to be encouraged, while the use of sugar-containing drinks and snacks between meals needs to be restricted to a maximum of 2 per day. Geographical differences need to be investigated in more detail.     

Clinical productivity indicators for a dental general practice residency program

Management of clinical productivity is an essential activity in the dental general practice residency GPR program. Because productivity is a relative term, indicators of clinical productivity must be developed to evaluate current performance. This article presents a 3-year study of clinical productivity in a two-resident GPR program. Productivity indicators are developed and analyzed for this program and for application to other GPR programs.     

In vitro effectiveness of dental floss in plaque removal

This study was designed to determine whether there was any measurable difference in the effectiveness of bacterial plaque removal between 4 commercially available dental flosses. By means of a highly standardized and controlled in vitro experimental model technique utilizing 50 freshly extracted third molars, the possibility of intra- and inter-individual variability was eliminated. Each tooth was individually mounted in a formatray block and the surface was finished to either a "planed" or "unplaned" surface configuration. The "planed" root surface (dentin) was achieved by using 600 grit wet-sandpaper for tooth surface reduction while the "unplaned" root surface was achieved by using 600 gift wet-sandpaper. The teeth were then individually processed to effect the growth of bacterial plaque (S. mutans) on the prepared surfaces. Each tooth was subsequently disclosed, flossed and photographed without interruption. The flossing was carried out on a flossing machine utilizing a controlled force of 50 g. A controlled direction of the stroke perpendicular to the long axis of the tooth, and a controlled frequency of flossing (2 strokes per trial) was used. The results of the clinical trials were evaluated utilizing Ektachrome slides of the previously flossed and disclosed tooth surfaces. The photographs were projected, measured, and statistically analyzed (Student t-test and paired t-test) for the effectiveness of plaque removal of the 4 dental flosses and the effect of root surface roughness on the ability of the flosses to remove bacterial plaque. It was found that on smooth, "planed" root surfaces, there were no measurable difference among the 4 flosses.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effectiveness of the thyroid shield in dental radiology

The effectiveness of the thyroid shield in reducing patient exposure during routine dental radiographic examinations was studied. A nonscreen film and two film-screen combinations were used as dosimeters and to show the spatial distribution of x-ray exposure. The error in the absolute accuracy of the film dosimeter and the error in the reproducibility of the film-screen combinations were less than +/- 10%. Measurements of thyroid exposure and exposure distribution, with and without the shield, were made on a Rando phantom and on patients. In the phantom study, the reduction by the shield of exposure to the thyroid from primary beam and from scatter was found to be highly dependent on the position of the primary beam relative to the thyroid gland but independent of kVp. Exposure reduction by the shield varied from 5% to 56% for a complete-mouth survey, 2% to 18% for a bitewing survey, and 10% to 79% for a panoramic survey. In the patient study, thyroid skin exposures measured on adults were 33% to 84% lower in offices in which the shield was used as compared to offices in which it was not used. Thyroid skin exposures measured on children were 63% to 92% lower. In accordance with the ALARA principle, these results support the routine use of the thyroid shield for all dental radiography.