Longitudinal study of the caries susceptibility of occlusal and proximal surfaces of first permanent molars

Risk Factors Associated with Carious Lesions in Permanent First Molars in Children: A Seven-Year Retrospective Cohort Study

The aim of this study was to evaluate the risk factors associated with the occurrence of caries in permanent teeth (PT) and in the permanent first molar (PFM) seven years after their eruption. Children born in 2005 who were enrolled in a Community Dental Program were included. A total of 278 children were enrolled. Evaluated risk factors were parental caries experience, educational level of the mother, routine medications, systemic diseases, dietary habits, toothbrushing frequency, existence of molar incisor hypomineralization (MIH) in the PT, and caries in the temporary teeth (TT). Associations between independent variables and the DMF-T (decayed, missing, and filled teeth in PT) and DMF-M (DMF in PFM) indices, only considering cavitated and non-cavitated carious lesions or cavitated carious lesions as outcomes, were evaluated by Poisson regression with robust variance analysis. A cariogenic diet (sweets and soft drinks), toothbrushing frequency of <1 a day, a presence of df-t (decayed and filled temporary teeth) score of >0, low educational level of the mother, and existence of MIH were associated with high DMF-T or DMF-M values (p < 0.05). We can conclude that the intake of sweets and soft drinks, toothbrushing frequency, the presence of caries in TT, and MIH in PT were the best predictors of the occurrence of caries in PT and PFM.

Fissure Depth and Caries Incidence in First Permanent Molars: A Five-Year Follow-Up Study in Schoolchildren

This study aimed to evaluate the association between the fissure depth (tooth morphology) of permanent molars and dental caries incidence with a five-year follow-up period. In total, 110 Mexican schoolchildren aged seven years were recruited at baseline, of which 88 children completed the follow-up assessments. The fissure depths of the first permanent lower molars were recorded, and dental caries [decayed, missing, and filled deciduous surfaces (dmfs) and decayed, missing, and filled permanent surfaces (DMFS)] was evaluated annually. A generalized estimating equation model was constructed for evaluating the association between dental caries and fissure depth. The initial and final DMFS scores were 0.02 (±0.2) and 1.55 (±2.49), respectively. The generalized estimating equation model showed that children with deep molar fissures were more likely to develop caries lesions, (Odds Ratio OR = 3.15, p = 0.028) compared to children with shallow fissures. Moreover, dental caries in primary teeth (OR = 1.07, p = 0.005) was associated with the development of carious lesions in the permanent dentition. Fissure depth was a useful predictor of dental caries, according to this five-year follow-up study. The detection of deep occlusal fissures in the lower first permanent molars could contribute to the identification of children at high risk of dental caries. Tooth morphology may be used to identify children at a higher caries risk, particularly in settings with limited resources.

A longitudinal study of occlusal caries in Newark New Jersey school children: relationship between initial dental finding and the development of new lesions

OBJECTIVE

Dental caries is a significant public health problem especially amongst children from low-income backgrounds. This longitudinal study examined the development of new occlusal caries in 227 Newark, NJ children ages 10-18. The role of previous caries experience and the presence of occlusal white and dark lesions in predicting the development of new lesions were examined.

DESIGN

At each visit, the patient's teeth were given a visual-tactile examination and the subject's decayed, missing and filled (DMFS) score was determined. Next, molars lacking probeable caries or restorations were examined using transillumination for occlusal white and dark spots. This examination was repeated periodically. A Cox proportional hazard was used to analyse data concerning the development of new occusal caries in molars.

RESULTS

The longitudinal data indicates that patients who were caries free at visit-1 developed significantly fewer occlusal caries during the longitudinal study. The hazard ratio for subjects who had first-visit caries was 2.27 compared to caries free subjects. Intact molars with occlusal white or dark lesions had caries hazard ratios of 0.78 and 1.49 respectively, compared to molars lacking initial colour changes.

CONCLUSION

Having a prior caries history places the subject at increased risk of developing future caries. Teeth with dark lesions but not white lesions are at significantly increased risk for developing decay. White lesions may represent remineralizing or slowly progressing lesions. The results of this study can help identify patients and tooth surfaces at risk for future occlusal decay.

The use of dental sealants in adults: a long-neglected preventive measure

The consensus among the general public appears to be that dental sealants are intended to be used primarily with children whose teeth are in the early developmental stage, yet little attention is given to the preventive long-term aspects when applying them to adult permanent dentition. This article explores the rationale and substantiates the use of dental sealants among the adult population in reducing occlusal pit-and-fissure caries while accentuating a beneficial oral health lifestyle.

Accuracy and reproducibility of conventional radiographic assessment and subtraction radiography in detecting demineralization in occlusal surfaces

Subjective interpretation of paired digital radiographic images viewed side by side to assess occlusal lesion progression, arrest or remineralization is difficult. The aim of this study was to compare the accuracy and reproducibility of a digital subtraction radiography technique and visual assessment of paired digital images in detecting changes in mineral content within occlusal cavities. Forty molar teeth with occlusal cavities were placed in arches and baseline digital radiographs taken. Nineteen teeth were randomly selected and had acid placed in the cavities and digital images taken after 3, 6, 12, 18 and 24 h of acid exposure. Paired baseline images and those taken at the various time intervals were examined side by side and assessed for demineralization by five examiners. Subtraction images prepared from the paired images were assessed in the same way. One fifth of the images were re-examined to determine intra-examiner reproducibility. After 12 h or longer the diagnostic accuracy (mean area under the ROC curve = 0.92-0.98 for subtraction radiography), intra-examiner and inter-examiner reproducibility for detection of demineralization from the subtraction images was significantly better than viewing the paired images side by side (p < 0.01). The subtraction radiography system used was found to be more accurate and reproducible than visual assessment of paired digital images. As such the technique shows promise for monitoring occlusal lesion progression in clinical studies.

Prophylactic efficiency of glass-ionomer fissure sealant

One of the most efficient prophylactic measures in caries prevention is sealing pits and fissures. After improvements of physical and mechanical properties, glass-ionomers are frequently used as sealing materials. The aim of this study was to evaluate the prophylactic efficiency of Fuji VII, a glass-ionomer fissure sealant, through adaptation ability and fluoride reeasing potential assessment using scanning electron microscopic and energy dispersive spectroscopic techniques. The sample consisted of 20 extracted intact human teeth, 10 premolars and 10 molars. Six sections of each tooth were analyzed using SEM. EDS analysis was conducted one week and three months after material placement. The parameters used for the evaluation included: adaptation ability, penetration depth, material structure, integrity of the interfacial zone and ion exchange extent. The sealant penetration depth was observed at 30 X magnification, and the interfacial zone between the material and the enamel at 500-10000 X. EDS was used for quantitative analysis of the material structure, interfacial zone and the enamel surface. The results were statistically analyzed the using chisquare test and descriptive statistical methods. SEM analysis revealed the zone of interaction between the enamel surface and the glass-ionomer with predominant cohesive failures within the sealant material, and satisfactory adaptation ability of the sealing material. The mean value of the penetration was 83% of the total fissure depth, without a statistically significant difference between the tested teeth groups. A lower penetration ability was observed in deep pits and fissures with a larger diameter of unfilled space (p<0.05). EDS analysis revealed the potential of the glass-ionomer for ion exchange with dental tissues. The presence of fluoride ions was detected in 2 sections 3 months after material placement. Glass-ionomers, chemically cured, biocompatible materials demonstrate satisfactory prophylactic characteristics.

Pattern of dental caries experience on tooth surfaces in an adult population

OBJECTIVES

To determine the pattern of caries experience across teeth and surfaces in an adult population depending on age and exposure to water fluoridation.

METHODS

Between November 2002 and March 2003 a total of 973 subjects aged 17-51 years had a clinical examination using visual and tactile criteria. Subsequent to this examination, bitewing radiographs were taken and viewed separately. Approximal and occlusal surfaces of molars and premolars were examined on the radiographs.

RESULTS

Caries experience was relatively low, with mean DMFS scores of 3.21, 5.12, 9.61, 13.04 and 24.35 for subjects aged 17-20, 21-25, 26-30, 31-35 and 36-51 years respectively. The first molar teeth had the greatest caries experience, and occlusal surfaces had more caries experience than approximal surfaces. Subjects with a lifetime exposure to fluoridated drinking water had significantly lower caries experience than those who had no exposure to fluoridated drinking water.

CONCLUSION

This study showed that caries prevalence, although relatively low in the study population, was found predominantly in occlusal surfaces, with an increasing prevalence in approximal surfaces of posterior teeth in older subjects. Subjects with a lifetime exposure to fluoridated drinking water had a lower level of caries experience than those with no exposure to fluoridated drinking water, and this was more noticeable in approximal surfaces than occlusal surfaces.

Effect of caries experience in primary molars on cavity formation in the adjacent permanent first molar

This study sought to address the influence of a sound versus affected first and/or second deciduous molar on the incidence of visible caries experience in the adjacent permanent first molar. Clinical and questionnaire data were obtained from a 6-year prospective oral health screening project in Flanders, Belgium (Signal-Tandmobiel project), where 4,468 children (born in 1989) were examined annually during their primary school time. A multiple survival model allowing for dependent data with possible censoring was applied. The impact of timing of tooth emergence (determining the period at risk), gender, presence of sealants and reported oral hygiene habits was also considered. Cavity formation in permanent first molars was clearly influenced by the status of the adjacent primary molars;the effect of the second deciduous molar was most pronounced. Moreover, if both deciduous molars experienced caries and the child presented with poor oral hygiene, a peak in cavity formation of the permanent first molar 1-2 years after emergence was noticed. On the other hand, if a child presented with good oral hygiene, no peak was observed; caries risk increased slightly over time. No significant benefit from restoring primary molars could be demonstrated, possibly because of methodological limitations.

Dental hygiene participation in managing incipient and hidden caries

With the advent of new caries detection devices that allow early detection, dental hygienists can intervene in the demineralization process and work with the patient toward remineralization through patient self-care procedures and the professional application of topical fluorides. The focus of this article is on caries detection devices, caries risk assessment, agents used to prevent dental caries, and the development of self-care plans for patients that include prevention, intervention, and therapeutic components.

Dental sealant longevity in a cohort of young U.S. naval personnel

BACKGROUND

The U.S. Navy emphasizes caries prevention and encourages the placement of dental sealants on the caries-susceptible teeth of patients at risk of developing caries. The authors analyzed dental records to assess the longevity of dental sealants placed in naval personnel.

METHODS

A cluster sample of dental records from 1,123 personnel who entered naval service in 1997 was drawn from eight Navy dental treatment facilities. The authors determined the number of sealants provided, the number of sealants that failed over the observation period (1997-2001), the dates of sealant failure and the longevity of sealants placed during and after recruit training.

RESULTS

A total of 319 personnel received sealants during their first two years of service. The authors evaluated 1,467 sealed teeth. They followed the sealants for an average of 35 months. They noted 179 sealant failures in 102 subjects; 69 previously sealed teeth required sealant replacement, and 110 sealed teeth required restoration of the occlusal surface. Among those sealants that failed, the mean length of time from placement to failure was 26 months. Sealant failure rates were significantly higher among subjects at moderate risk or high risk of developing caries than among subjects at low risk.

CONCLUSIONS

After an average of 35 months, 87.8 percent of the sealants placed in this population were retained and functional. Subjects who were at moderate or high risk of developing caries demonstrated significantly higher sealant failure rates than those at low risk of developing caries.

CLINICAL IMPLICATIONS

Dental sealants can be retained successfully in adults. They should be considered a viable treatment alternative for adult patients who are susceptible to caries; however, patients at elevated risk of developing caries may require more frequent re-evaluation and maintenance to achieve maximum benefit.

Exposure to fluoridated drinking water and dental caries experience in Australian army recruits, 1996

OBJECTIVES

The purpose of this study was to investigate a group of young Australian adults to determine their caries experience and measure associations between caries experience and age, gender, socioeconomic status, education level and lifetime exposure to fluoridated water.

METHODS

This was achieved through a cross-sectional study involving Australian Army recruits seen for their initial dental examination on enlistment into the Australian Army. A total of 499 recruits had a clinical examination with the aid of bitewing radiographs and an orthopantomograph (OPG). Sociodemographic and fluoride exposure data were obtained via a questionnaire.

RESULTS

This study showed that subjects with a lifetime exposure to fluoridated water reported a 23% lower level of caries experience than subjects with no exposure to fluoridated water, with a greater effect on proximal surfaces compared to smooth and occlusal surfaces. Female subjects had a level of caries experience 25% higher than male subjects, while subjects from the lowest socioeconomic background had a level of caries experience 89% times greater than subjects from the highest socioeconomic group.

CONCLUSIONS

Although it is not possible to directly establish a causal relationship from a cross-sectional study such as this, the results from this study show a dose-response relationship which suggests that there are benefits of lifetime exposure to fluoridated drinking water through young adulthood.

Comparing the costs of three sealant delivery strategies

We analyzed the cost-effectiveness of 3 sealant delivery strategies: Seal all (SA), seal children assessed to be at risk by screening (TARGET), and seal none (SN). We assumed a nine-year analytic horizon, a 3% discount rate, and zero screening costs. Estimates for sealant costs ($27.00) and restoration costs ($73.77), annual caries increment (0.0624 surfaces), sealant failure rate (20% in yr 1 and 3% thereafter), annual amalgam failure rate (4.6%), and sensitivity (0.635) and specificity (0.795) of screening were obtained from published studies. Under baseline assumptions, TARGET dominated (cost less and reduced caries) SA and SN. If annual caries increment exceeded 0.095 surfaces, SA dominated TARGET, and if increment exceeded 0.05 surfaces, TARGET dominated SN. If sealant costs decreased to $6.00 (reported cost for school programs), TARGET dominated SN for caries increments exceeding 0.007 surfaces, and SA dominated TARGET for caries increments exceeding 0.034 surfaces.

Reviews of evidence on interventions to prevent dental caries, oral and pharyngeal cancers, and sports-related craniofacial injuries

This report presents the results of systematic reviews of effectiveness, applicability, other positive and negative effects, economic evaluations, and barriers to use of selected population-based interventions intended to prevent or control dental caries, oral and pharyngeal cancers, and sports-related craniofacial injuries. The related systematic reviews are linked by a common conceptual approach. These reviews form the basis of recommendations by the Task Force on Community Preventive Services (the Task Force) about the use of these selected interventions. The Task Force recommendations are presented in this supplement.

A 13-year follow-up of a comprehensive program of fissure sealing and resealing in Varkaus, Finland

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.

Trends in preventive care: caries risk assessment and indications for sealants

BACKGROUND

In the 21st century, risk assessment models will continue to be developed. By understanding patients' susceptibility to disease, better treatment and preventive regimens can be offered. As the causative agent of dental caries is bacterial, the interaction between the susceptible host, the causative agent and the environment determine whether caries occurs--regardless of the patient's age.

CLINICAL IMPLICATIONS

This article reviews risk assessment for dental caries and the implication for developing preventive strategies. It also describes the indications and uses of sealants in the prevention of dental caries.

Prevalence and attitudes to fissure sealants in the general dental service in England

OBJECTIVES

The study objectives were to investigate changes in the prevalence of fissure sealants over a 5-year period among a comparable group of 14-15-year-old regular dental attenders registered with general dental practitioners in 1989 and 1994, and to investigate attitudes towards this form of care amongst general dental practitioners in 1994.

METHODS

Random samples of 14-15-year-old pupils were selected from school lists in three areas in England (Doncaster, Hereford/Worcester and Wycombe) in 1989 and 1994. Once parental consent had been gained to examine the children, the Dental Practice Board (DPB) indicated which subjects were 'regular attenders', only these subjects were included in the study. All the subjects in each area were examined by a single trained and calibrated examiner using a standardized technique. In 1994, a group of randomly selected dentists in each area completed a telephone questionnaire assessing attitudes and treatment patterns regarding fissure sealants.

RESULTS

In 1989, 2836 letters were posted to parents asking for consent to examine their child and 2174 positive responses were received (response rate 77%). Of the 1919 children examined, 459 were classed as regular attenders, 140 in Doncaster, 159 in Hereford/Worcester and 160 in Wycombe. In 1994, 2560 consent letters were distributed to children in school to pass to their parents and 1587 positive responses were received (response rate 62%). Of the 1388 children examined, 891 were classed as regular attenders, 294 in Doncaster, 318 in Hereford/Worcester and 279 in Wycombe. Large rises in sealant prevalence were observed in all areas, but particularly in Doncaster where sealant prevalence increased from 13% in 1989 to 50% in 1994. In Hereford/Worcester it increased from 25% to 47% and in Wycombe it increased from 16% to 30%. There was also a fall in mean DMFT in all areas. In Doncaster it fell from 2.97 in 1989 to 1.82 in 1994, in Hereford/Worcester it fell from 2.60 to 1.83 and in Wycombe it fell from 1.86 to 1.29. In all three areas the changes in sealant prevalence and DMFT were statistically significant. The questionnaire revealed positive attitudes towards fissure sealants and their usage as well as a number of areas of concern that could potentially hinder sealant usage.

CONCLUSIONS

Dramatic increases in sealant prevalence and considerable reductions in dental caries among these regularly attending adolescents have been demonstrated. Some concerns were highlighted regarding sealant usage, which may be prejudicing further increases in their application.

An evaluation of sealant restorations after 2 years

AIM

To obtain evidence of the efficacy of sealant restoration used in the management of fissure caries.

DESIGN

A controlled study in a UK dental hospital environment.

METHODS

Suspect fissure lesions were investigated in 164 young adult patients attending for routine dental care. Only one test tooth per subject was included in the study. Patients were recalled after 6, 12 and 24 months at which time the fissure sealant retention and the performance of the restorative materials were noted.

RESULTS

Successful recall was achieved with 91.5% of patients. Most teeth treated (92%) involved the preparation of an investigative cavity. The mean age of patients treated was 23.9 years and second permanent molar teeth were the most commonly affected teeth requiring treatment in this age group. The presence of small composite restorations did not adversely affect fissure sealant retention but after 2 years, significantly more sealant was lost from the surface of light cured glass-ionomer cement and larger composite restorations.

CONCLUSIONS

Sealant restorations provide an effective method of management of fissure caries in young adult patients.

Oral hygiene in the control of occlusal caries

Occlusal pit and fissure caries accounts for a high proportion of the total caries burden among children. Studies from Denmark suggested that oral hygiene measures may be effective in the control of occlusal caries in permanent teeth. This study reports on the findings after 24 months of a controlled field trial comparing the caries-preventive effects of a professional tooth-cleaning and dental health education programme (test) with a standard preventive programme (control), comprising selective fissure sealing and application of topical fluorides. School Dental Service clinics of the Health Department of Western Australia, in Perth, were assigned to four test or four control clinics. Schoolchildren, mean age 6 years, with sound newly erupted first permanent molars were included in the study (207 test, 197 control). After 24 months, 179 test and 156 control children were examined by a calibrated examiner who was 'blind' to the test or control status of the child. Thirty-two test and 31 control children developed occlusal caries on the first permanent molars; the estimated risk ratio was 0.90 (95% CI 0.58-1.41). Children in both groups had an average DMFT score of 0.30. The 24-month results suggest that the two preventive programmes did not differ with respect to the control of occlusal caries in newly erupted molars.

A comparison of two histological validating techniques for occlusal caries

Validation of a diagnostic technique is important to establish whether it actually measures what it is purported to measure. However, the accuracy of the validation technique per se can influence the apparent accuracy of the diagnostic technique.

OBJECTIVES

The aim of this study was to describe two alternative histological validating techniques for occlusal caries and to compare quantitative depth measurements of carious lesions taken using each method.

METHODS

Thirty sections (mean thickness 0.67 mm) were cut to include two to four discrete sites in 10 freshly extracted teeth. The first histological validating technique used a microfocal X-ray unit to produce magnified high definition radiographic images of the sections or 'macroradiographs'. An image analysis system was used to make quantitative measurements of the lesions (if present) with respect to the enamel-dentine junction (EDJ). The second validating technique used a confocal microscope to image beneath the cut surface of the section. Quantitative measurements were taken from the fluorescence images of both sides of each section and a mean depth measurement calculated.

RESULTS

Complete agreement was found between the two validating techniques for the subjective interpretation of the presence and extent of caries. A strong positive relationship was found between the two histological validating techniques for depth measurements made of dentine caries from the EDJ (r = 0.93, P < 0.001). Depth measurements made from the macroradiographs were greater than from the confocal fluorescence images (mean difference = 0.41 mm).

CONCLUSIONS

Both validating techniques enable the identification of sound sites, those with enamel caries and dentine caries. However, quantitative assessments made with each technique could result in disagreement.

Hidden caries: what is it? Does it exist? Does it matter?

Hidden caries is a term used to describe occlusal dentine caries that is missed on a visual examination, but is large enough and demineralised enough to be detected radiographically. The detection rate of such lesions will depend upon the prevalence of caries in the population and the frequency with which bitewing radiographic examinations are performed. Whether 'hidden caries' is a distinct clinical entity, reflecting a particular anatomical fissure topography or a different bacterial aetiology, is unknown. It is possible that an improved visual examination, with careful cleaning and drying of teeth, may improve occlusal caries detection to the point where 'hidden caries' no longer exists. However, this possibility has yet to be tested clinically and until it is, practising dentists would be wise to examine bitewing radiographs carefully for occlusal demineralisation. The authors would treat such hidden lesions by removing soft caries and placing sealant restorations.

Incremental susceptibility of individual tooth surfaces to dental caries in Scottish adolescents

This study reports on the caries susceptibility of tooth surfaces in 4294 adolescents (mean age 12.5 yr) during a 3-yr, double-blind clinical caries trial, conducted in Lanarkshire, Scotland, between 1988 and 1992. Children were selected on the grounds of dental maturity and past caries experience. Clinical examinations with mirror, CPITN probe and fibre optic trans-illumination were carried out on the permanent dentition, with the buccal pits of mandibular molars and palatal pits of maxillary molars being recorded as separate sites. At baseline 6061 surfaces were decayed (1.0% of 601 160 surfaces examined), 20 160 (3.4%) filled, and 10 909 (1.8%) missing due to caries. The number of surfaces recorded as sound at baseline in subjects completing the study was 454 663. Of these 8176 (1.8%) new surfaces were decayed, 14 832 (3.3%) filled and 4000 (0.9%) missing at the final examination. Molar occlusal surfaces showed greatest susceptibility to attack, 35.8%) of those at risk becoming carious in the course of the study. All buccal and lingual smooth surfaces showed a low susceptibility, but 8.8% of buccal and palatal pits developed caries. At the final clinical-only examination, pit and fissure caries accounted for 48%, interproximal surfaces for 39%, and smooth surfaces for 13% of caries prevalence. However, overall the contribution of these surfaces to 3-yr increments was, 40%, 47% and 13%, respectively.

The prevalence of dental sealants in the US population: findings from NHANES III, 1988-1991

Over the past decade, dental sealants have become recognized as an important adjunct to the use of fluorides in the prevention of dental caries. The most recent national survey of oral health in children conducted in 1986-1987 found that only 7.6% of children had any sealed teeth. As part of the oral health component of the 1988-1991 Third National Health and Examination Survey (NHANES III-Phase 1), the prevalence of dental sealants in children, adolescents, and adults was determined. The presence of dental sealants on posterior teeth (excluding third molars) and maxillary lateral incisors was recorded by visual and tactile methods during the dental caries examination. Findings in this paper are based on those examined persons having at least one sealable primary tooth for children aged 2-11 years (n=3,792); at least one sealable premanent tooth for persons aged 18 years and over (n=7,146). During 1988-1991, about 18.5% of US children and youth ages 5-17 had one or more sealed permanent teeth. A significantly higher percentage of non-Hispanic whites had sealants in comparison with their non-Hispanic black and Mexican-American counterparts (for all contrasts, p<0.001). As expected, molar teeth were the most frequently sealed tooth type. Only 1.4% of US children ages 2-11 had at least one sealed primary tooth. The prevalence of dental sealants decreased in the US adult population with increasing age; 5.5% of adults ages 18-24 had at least one sealed permanent tooth. Data collected from NHANES III-Phase 2 (1991-1994) will be analyzed to determine if the upward trend in sealant use continues.

The impact of recent changes in the epidemiology of dental caries on guidelines for the use of dental sealants

This paper reviews recent changes in the epidemiology of dental caries and assesses their potential impact on the diagnosis and management of the disease and the planning and operation of sealant programs. These changes, such as the decline in caries and slowing of the rate of progression of the disease, have important implications for diagnosing and treating incipient lesions, predicting caries risk, and conducting effective disease preventive programs. Traditional paradigms for restoring carious lesions are being replaced by newer strategies that emphasize disease prevention and conservation of tooth structure. The search continues for the identification of practical models for predicting caries risk at the individual level. This paper describes a method useful for targeting resources in sealant placement programs by enabling one to determine the relative effectiveness of sealing alternative tooth surfaces in the oral cavity. One guide serves as a widely adopted manual for those who use or intend to use dental sealants in caries prevention programs. This paper provides a brief review of that document, "Preventing Pit and Fissure Caries: A Guide to Sealant Use," as well as guidelines for sealant utilization provided by the American Dental Association, and information regarding dental sealant programs under Medicaid. The final portion of the paper provides a synthesis of the epidemiology reviewed and summarizes the implications of findings for sealant programs.

The impact of recent changes in the epidemiology of dental caries on guidelines for the use of dental sealants: clinical perspectives

When used properly, sealants result in improved dental health. However, their use on all occlusal tooth surfaces for preventive reasons will result in wasted dental care resources. To optimize the preventive effects of sealants, a delivery model should be initiated that uses specially trained dental hygienists or dental assistants who visit schools to explain oral health-related issues, conduct visual inspections of clinical oral health status, identify patients at risk for dental caries, and generate a central database for program operation. When a high-risk patient is identified, auxiliary personnel could place sealants and recall the patient for a new visual inspection six months later. If caries is suspected at that time, the patient could be sent to a dentist for additional treatment. To offset the negative effects caused by overutilization of sealants, their usage should be divided into two categories. First, a preventive option should be available, and the fee for use of sealants in this option should be lower compared to the fees used today. By using specially trained auxiliary personnel to place such sealants, the fee could be kept reasonably low. Second, a sealant treatments option that targets treatments of incipient lesions also should be available. The fee for such a treatment should be close to that of the traditional occlusal restoration, and the application should be by a dentist. By using such a fee structure based on market forces, one would expect that sealant usage would increase among patients suffering from early carious lesions, while the usage of preventive sealants would remain the same or decline. This utilization pattern for dental sealants would contribute to improved efficiency of sealant usage in the treatment of dental caries, particularly at a time when caries frequency is declining. The improved efficiency could release dental care resources that should be used to target risk groups with improved education in dental health. By using such a strategy, the long-term effect would be not only the placement of fewer restorations, but an improvement in dental health among adolescents and adults.

Timing of first fillings on different permanent tooth surfaces in Finnish schoolchildren

The timing of the placement of first fillings because of caries on different permanent tooth surfaces was determined at three health centers in Finland. The 927 subjects analyzed were born either in 1970-71 o4 in 1980-81. Basically, two different types of filling placement site were identified: 1) fissures and pits and 2) proximal and smooth surfaces. In some fissures and pits a 'post-eruptive'--that is, fillings placed in the year of emergence--was observed. This step had decreased markedly in the cohort born in 1980-81. The curves plateaued (retardation phase) at 50-60% for the occlusal surfaces in first molars for the children born in 1970-71 and at 20-30% for the younger cohort. The time without any filling varied from 1 to 7 years on smooth surfaces, and some surfaces remained totally filling-free. The filling placement curves followed the pattern of caries attack and can thus be used as an indicator of dental health.

Pit and fissure sealants: another major cornerstone in preventive dentistry

Despite dramatic reductions in caries in fluoridated communities, the disease continues to occur during childhood and adolescence and there is a sustained caries susceptibility of pits and fissures. Pit and fissure sealants have been available to the dental profession for the past two decades. Closely following community water fluoridation, this use of adhesive technology is now recognized as a major cornerstone of modern preventive dentistry. However, the technique appears to have been slow in implementation by the dental profession. Recent expanded utilization of sealants in the public sector, particularly in Victoria, has increased the awareness of the procedure amongst the public and is heightening demand. A review of the pertinent literature and current trends in utilization of sealants is presented. The case is made for expanded utilization of sealants in both the public and private sectors of dental health care delivery in Australia.

Clinical and radiographic diagnosis of occlusal caries: a study in vitro

Various methods of diagnosing occlusal caries have been described, but only visual, clinical examination and radiographic examination are commonly used in dental practice. This laboratory study investigated the ability of 12 examiners to detect the presence or absence of occlusal caries in 48 extracted molar teeth using these two techniques. The presence or absence of caries was subsequently verified by sectioning the teeth. Diagnosis from visual examination was poor, only 48.7% of lesions in dentine being detected. Radiographic diagnosis was better with 62.2% of dentine lesions being found. However, this increase in sensitivity of the diagnosis was accompanied by a decrease in specificity with the number of false positive diagnoses increasing when the radiograph was used. Therefore, although the bite-wing radiograph may be regarded as a safety net for the diagnosis of occlusal caries, it must be interpreted with caution bearing in mind the possibility of false positive diagnoses.

Clinical assessment of glass ionomer/composite resin sealant restorations in permanent teeth: results of a field trial after 1 year

A large field trial is in progress in the Community Dental Service in the West of Scotland to evaluate the effectiveness of glass ionomer/composite resin sealant restorations in the treatment of fissure caries. 128 of the restorations were placed by 14 community dental officers. After 1 year, 98 restorations were reviewed. All of the glass ionomer restorations were retained but only 12 of the sealants were completely intact. Sealant was retained over only 32% of the restorations and in 13%, 48% and 69% of adjacent buccal, occlusal and palatal fissures, respectively.

A comparison of dental caries experience in Native American and Caucasian children in Oklahoma

OBJECTIVES

In 1989 the Oklahoma Area Indian Health Service conducted an oral health survey of children attending public schools in Oklahoma to determine the extent of caries experience in the Native American population. Results were to be used to establish program priorities, gather baseline data, and compare the oral health status of Native American children with their non-Indian peers.

METHODS

A total of 934 elementary schoolchildren 5-6 years of age were examined along with 733 high school students 15-17 years of age. The study was designed so that approximately 50 percent of the students examined were Native American.

RESULTS

The mean dmfs for the 5-6-year-olds was 5.06 for the Caucasian children and 10.35 for the Native American children, a statistically significant difference (P < .001). For the 15-17-year-olds the mean DMFS for the Caucasian students (5.99) was significantly lower (P < .001) than the mean DMFS for the Native American students (10.12).

CONCLUSIONS

The prevalence and severity of caries in these Native American students appear to be substantially higher than in their non-Indian peers residing in the same communities. Further study is needed to identify factors contributing to these demonstrated differences in caries experience.

Parental knowledge and attitudes towards pit and fissure sealants

No survey of public knowledge and attitudes towards pit and fissure sealants has been carried out in Australia. This study assessed the knowledge and attitudes of parents of Melbourne school children attending five dental treatment centres, regarding sealants. Of 554 parents surveyed by questionnaire, 487 (88 per cent) provided codable responses which were analysed by the log-likelihood ratio statistic and three-way hierarchical log-linear regression models. A total of 57.5 per cent respondents had heard of sealants; 46.4 per cent knew sealants prevent dental caries, and 45 per cent rated sealants important in caries prevention. Respondents attending private dentists or the Dental Therapy School were more knowledgeable about sealants than those attending other centres. Sealant awareness was related significantly to gender (p < 0.05), country of origin (p < 0.05), family income (p < 0.05), and frequency of dental visits of children (p < 0.001); the apparent association with country of origin, and annual family income, was explained by interactions between these variables and treatment centres. Dentists were the main source of dental health information including sealant awareness (p < 0.001). The most significant factors in sealant awareness were previous discussion of caries prevention by respondents with dentists; dentists as the main source of dental health information; and frequency of dental visits by the child(ren). These three factors confirm the importance of dentist-patient interactions in disseminating oral health information.

Performance of diagnostic systems in occlusal caries detection compared

Many investigations have been conducted to evaluate existing and new diagnostic systems in the detection of occlusal carious lesions. The performances of these systems are difficult to compare with each other, because of the disadvantages associated with the widely used validity parameters sensitivity and specificity. In this study a meta-analysis was performed to facilitate a comparison between the performances of diagnostic systems which are currently in use in occlusal caries diagnosis. Nine in vitro studies and one in vivo study complied with the selected criteria for inclusion in the analysis. The sensitivity and specificity values obtained from these studies were converted into normal deviate values, and plotted on linearly scaled normal-deviate axes. DZ values, which quantify the performance above chance of a diagnostic test in one single value, were calculated. Averaged DZ values of the diagnostic systems were subsequently compared to each other. The results indicate that electrical resistance measurements and fiber-optic transillumination had a comparatively good, and visual inspection and xeroradiography a poor, performance in occlusal caries diagnosis. All the other radiographic image modalities had intermediate performances.

Sealant prevalence and indication in a young military population

The prevalence of sealants and indications for their use was surveyed in U.S. Air Force personnel younger than 26. Sealants were found on 13.1 percent and indicated for 47.5 percent. About a third of all personnel had occlusal caries, which might have been prevented by sealants.

Occlusal dental caries incidence and implications for sealant programs in a US college student population

Given the decline in dental caries incidence in preteens and young teenagers in the United States, a study of the incidence of dental caries in young adults (17-23 years) was conducted to provide a descriptive epidemiologic picture of this "new" natural history of dental caries in the late and post-teenage years. A retrospective study was performed analyzing the detailed dental records of the four-year college experience in the class of 1989, US Coast Guard Academy. Occlusal caries incidence, in the absence of associated proximal caries, was shown to be moderately common in molars (11.9%) and rare in premolars (0.8%). In contrast to previous studies' findings, demographic indicators, socioeconomic status indicators, and prior caries experience were poor predictors of occlusal caries incidence; targeting a universal sealant policy in this population therefore would be done best by tooth type rather than patient type. A preliminary cost-comparison model, projected over a 40-month period, suggests that the cost of initiating a universal molar sealant policy in this population would be 92 cents per year per student greater than the cost of restoring occlusal caries in the presence of sound proximal surfaces. This cost comparison suggests that it would be advantageous to initiate such a policy.

Occlusal caries diagnosis: a changing challenge for clinicians and epidemiologists

The diagnosis of occlusal caries is an integral part of an epidemiologist's task, whether carrying out cross-sectional national caries prevalence surveys to assist with planning and the evaluation of service provision, or clinical trials of caries preventive agents. Similarly, the clinician also carries out this same overall diagnostic procedure in order to plan care for individual patients, although he/she will usually have access to improved facilities and diagnostic aids. This paper reviews the different problems now being encountered by both epidemiologists and clinicians in the face of changes in the presentation of the disease at this site and the qualifications which should now be appreciated when extrapolating from the results of surveys employing comparatively gross criteria. It explores recent developments in diagnostic aids and makes suggestions as to how further information might be obtained in future which would aid the valid comparison of diagnoses made by these two groups of dentists.

Comparison of tooth surface-specific dental caries attack patterns in US schoolchildren from two national surveys

The 1979-1980 and the 1986-1987 National Institute of Dental Research (NIDR) surveys of school-aged children revealed that virtually all tooth surfaces experienced a decrease in caries prevalence during the inter-survey period. Overall, there was a 28% decrease in the proportion of tooth surfaces attacked by caries for the primary dentition between the two surveys. The decrease for primary incisors was numerically small (5 surfaces per thousand surfaces at risk) and not statistically significant, whereas decreases in the canines and primary molars were considerably larger (23 surfaces per thousand) and statistically significant. For the permanent dentition, the overall decrease in the proportion of surfaces attacked was 35% during the 1979-87 period. Differences between the two surveys in the proportions of surfaces with caries were largest for pit and fissure surfaces (56 surfaces per thousand), followed by those for posterior approximal surfaces (14 surfaces per thousand) and all other smooth surfaces (5 surfaces per thousand). Almost all of these differences were statistically significant, except for some surfaces which experienced very few caries.

A retrospective analysis of the cost-effectiveness of dental sealants in a children's health center

A retrospective patient record analysis was conducted to study the cost-effectiveness of dental sealants placed under routine, unrestricted practice condition in a fluoridated community. The 26 dentists who provided care at the clinic over the period of the study used their own clinical judgement to determine sealant placement or alternative treatment. Dental services for 275 patients at a children's dental clinic for low-income families were evaluated. All children had at least 3 years between their first and last dental visit (mean = 5.8 years). A lifetable analysis was conducted to compare the probability of survival (restoration-free tooth years) and costs incurred to first molars of children who did not receive sealants, received any sealants, or received sealants on all first molars. Among the children with sealants, comparisons were also made between sealed and unsealed teeth in children who did and did not have a first molar restoration prior to sealant placement. Costs included the costs of sealants and restorative treatments for these teeth over time. Depending on the conditions under which sealants were placed, cost-savings or improving cost-effectiveness with time were found. A strategy of identifying children with prior restorations and sealing the remaining molars showed cost-savings within 4-6 years. For other comparisons, incremental cost-effectiveness ratios became more favorable over time.

Comparison of number and mean charge between dental sealants and one-surface restorations

An important concern of the insurer is how sealants, if a covered benefit, will affect the premium. Important factors that may have an influence on determining the premium include the decline in caries rate coupled with the long-term cost to an insurer for sealants vs one-surface restorations. In this study of more than 1 million dentally insured children (aged 5-15), the mean charge ($) for sealants and one-surface restorations was determined, along with the frequency of these procedures, by patient age. For this group of children, 43 percent of one-surface restorations occurred between ages 12-14, whereas 32 percent of the patients received sealants at either 7 or 8 years of age. States varied substantially in the number of sealants as a percentage of the number of restorations. Only three states had more sealants placed than one-surface, posterior restorations. Three states had an annual increase in the ratio of sealant to restoration charge, while 13 states had an annual decrease. With the exclusion of a few states with a minimum number of sealants and restorations in 1988, the highest ratio of the cost of sealants to the cost of one-surface restorations was observed in New York (.60) and New Jersey (.56) and the lowest observed in Kansas and Utah (.37). The ratios for both New York and New Jersey were lower in 1988 than in the previous two years. The ratio of the number of one-surface, posterior restorations to the population served was approximately the same for each NIDR region in the contiguous United States. Alaska and Hawaii had a higher proportion.

Decline in dental caries and public oral health care of adolescents

The adequacy and appropriateness of the oral health service were evaluated from patient records of 15-year-olds in Helsinki in 1976 and 1986. The subjects selected for the study represented the whole age group participating in public oral health service in the 2 years in question. During the 10 years, substantial decreases were seen in the mean numbers of dental visits (from 4.0 to 2.4) and fillings (from 2.9 to 1.2). The greatest decrease was seen in the number of fillings made in incisors. Slightly fewer preventive measures were carried out in 1986 than 10 years earlier, but no focusing on risk patients was seen. In the 2 years studied, 15-year-olds in the high-risk group received applications of topical fluorides and instructions on oral hygiene as often as those in the low-risk group. A major problem seemed to be the increasing number of unfinished courses of treatment among high-risk patients. We conclude that patients with a higher risk of caries should receive more attention with regard to both the preventive treatment given and ways of motivating them to complete their treatment courses.

An eight-year follow-up of the occlusal surfaces of first permanent molars

The state of the occlusal surfaces of the first permanent molars (FPMs) in a representative group of subjects from seven to 15 years of age was followed retrospectively year by year. Data were taken from oral health records. Standardized charts include information on dental check-ups, oral health status, and the treatment given. The state of each occlusal surface was classified into four categories: (1) sound but unsealed, (2) sealed, (3) filled, or (4) decayed. An overall annual attack rate for all occlusal FPM surfaces was 5.9% per year, and for approximal surfaces, 1.3%. Occlusal caries attacks had been most prevalent between seven and nine years of age, whereas new approximal lesions had been most frequent from ages 11 to 13. The FPMs that had been sealed at the age of seven developed fewer caries than did any other group during the follow-up.

A critique of topical fluoride methods (dentifrices, mouthrinses, operator-, and self-applied gels) in an era of decreased caries and increased fluorosis prevalence

Within the last 20 years there has been a decrease in the caries prevalence of US schoolchildren, a change in the intraoral caries pattern, and a slowing of the progress of lesions. Simultaneously, the prevalence of enamel milder, cosmetically acceptable forms and is more noticeable in fluoride-deficient communities than those with optimal or above-optimal water fluoride concentrations. Circumstantial evidence indicates that a principal contributor to the caries decline is the extensive use of fluoride dentifrices. Conversely, although use of a fluoride dentifrice can add to the total daily amount of ingested fluoride in preschool children, there is little evidence to suggest that dentifrice ingestion is a principal factor causing the fluorosis increase. The value of fluoride methods may be assessed in relative or absolute terms. The relative, or percentage, caries reduction attributed to fluoride mouthrinses and gels appears to be a property intrinsic to the methods themselves and generally is little affected by the caries activity of the population being treated. Conversely, the absolute, or numerical, caries reduction is dependent upon the level of disease in the population. Thus, the reported caries decline reduces the number of surfaces prevented from developing caries, even though the percentage reduction remains substantially unchanged. Although inadvertent ingestion of fluoride can result from the use of mouthrinses and gels, there is little evidence to suggest that they have contributed to the fluorosis increase. When using topical methods, prudence should prevail to avoid ingestion of fluoride. Fluoride dentifrices should continue to be used routinely, and although lower potency dentifrices may be considered, the literature does not provide strong support for their need. Use of fluoride mouthrinses and gels for individual patients should be predicted upon their caries activity or risk. Use of these methods in public health programs is a matter of cost-effectiveness, which will be influenced by the caries prevalence of the target population.

The effectiveness of pit and fissure sealants

This review addresses two major issues related to the use of pit and fissure sealants. First, the epidemiology of occlusal caries for children and adults is examined to determine if there is a basis for administering sealant programs to different age groups. Second, the effectiveness of pit and fissure sealants in fluoridated and non-fluoridated communities is compared. Changes in effectiveness of sealant over time are evaluated in terms of percent effectiveness, complete retention, caries incidence, and reapplication rates. Based on epidemiologic evidence, sealant programs can be justified for children and young adults, but not for older age groups. Based on the literature reviewed, following one application of autopolymerized or visible-light-cured sealant, the median percent effectiveness declines from 83 percent after one year to 55 percent after seven years. Similarly, the median complete retention declines from 92 percent after one year to 66 percent after seven years. Conversely, the median percent of sealed first molars becoming carious and/or restored increases from 4 percent after one year to 31 percent after seven years. Large differences in sealant effectiveness are not apparent between studies performed in fluoridated and fluoride-deficient communities.

Long-term effect of xylitol chewing gum on dental caries

About 85% (n = 269) of the subjects who participated in the Ylivieska follow-up studies on the effect of xylitol chewing gum on dental caries during 1982-84 or 1982-85 were re-examined in 1987 for the analysis of possible long-term preventive effects. Further caries reduction was found 2 or 3 yr after the discontinuation of the use of xylitol. The effect was especially marked in girls; the reduction in caries increment in the post-use years was 60% for the 2-yr users, suggesting that more pronounced caries reduction was associated with the most regular use of xylitol. In teeth erupting during the first year of the use of xylitol gum the long-term preventive effect was greater than in other teeth. Several explanations are suggested: lasting effect of the microbiological changes in the mouth, bacterial colonization on newly erupted teeth by organisms other than S. mutans, and/or thorough maturation of the teeth under favorable physico-chemical circumstances. The results suggest that the value of xylitol in caries prevention depends on the timing of the treatment in relation to the development of the dentition.