Approximal Enamel Lesions Research Articles

Chapter 6: Diagnostic Considerations regarding Coronal Caries.

This chapter considers the main principles guiding diagnosis of the disease dental caries in clinical practice by means of clinical examination and radiographs as adjunct method. Dental professionals have been trained to diagnose caries disease by assessing clinical symptoms and signs of caries lesions complemented by radiographic examination as an adjunct method. Clinical examination is the foundation of the diagnosis and should be performed after removal of dental biofilm of tooth surfaces, air-drying, and under good illumination. Clinical diagnostic methods categorize caries lesions according to their severity and in some methods according to their activity. Caries lesion activity has been determined by surface reflection and texture. The detection of thick or heavy biofilm on tooth surfaces is an additional diagnostic clinical tool to estimate caries lesion activity. Patients with no caries experience, that is, without clinical and/or radiographic signs of caries lesions in the dentition, are considered caries inactive. Other caries-inactive patients may present inactive caries lesions/restorations in their dentition. In contrast, patients are considered caries active when presenting any active caries lesion at clinical level and/or any progressing lesion as demonstrated by at least two bitewing radiographs taken at different points in time. The main concern about caries-active patients is that caries lesions are likely to progress unless effective measures are implemented to interfere with its progression. Prescribed according to individual needs, bitewing radiographs provide additional information for clinical examination in the detection of approximal enamel and outer third dentine lesions that can be inactivated by nonoperative treatment.

A comparison of near-infrared imaging with other diagnostic tools for dental caries.

Dental caries is one of the most common diseases in the world, and global incidence rates are increasing. The early detection of dental lesions enables a conservative approach to be employed and represents a priority in modern dentistry. Recent studies have suggested that conventional diagnostic methods, such as visual tactile inspection and X-ray examination, exhibit low sensitivity and are not very effective in early diagnoses. Consequently, late detection of decay is associated with an increased loss of tooth structure. New diagnostic systems based on optical properties have been developed to facilitate early detection. Several studies have evaluated the performance of near-infrared imaging (NIRI) as an early diagnostic tool. NIRI using light ranging from 700 to 1700 nm has demonstrated better optical properties compared to conventional optical systems using light in the visible spectra. NIRI enables deeper penetration of the light in the tooth tissue, weak scattering with lower background noise and strong photon absorption with detailed images. Several in-vivo studies have demonstrated that NIRI technology has the potential to improve performance compared with current diagnostic methods. NIRI exhibits increased sensitivity compared to radiographs and is more suitable to identify approximal enamel lesions. This paper aimed to review these recent advances and their potential applications in daily clinical practice.

Effect of nano-hydroxyapatite and ozone on approximal initial caries: a randomized clinical trial

The aim of the study was to assess the efficacy of three methods of enamel remineralization on initial approximal caries: (1) a nano-hydroxyapatite gel, (2) gaseous ozone therapy, (3) combination of a nano-hydroxyapatite gel and ozone. Patients (n = 92, age 20–30 years) with initial approximal enamel lesions on premolar and molar teeth (n = 546) were randomly allocated to three groups subjected to a 6-months treatment: Group I: domestic nano-hydroxyapatite remineralizing gel, group II: in-office ozone therapy, group III: both domestic remineralizing gel and ozone therapy. Caries lesions were assessed on bitewing radiographs at baseline, after 1 year and after 2 years. At one-year follow-up, the smallest rate of lesions with remineralisation (36.5%) was found in group I, and the highest (69.3%)—in group III. In group III a significant remineralisation was noticed in after 1 year and then a demineralisation after 2 years. Thus nano-hydroxyapatite gel and ozone therapy exert some capacities to remineralize approximal enamel and dentine subsurface lesions of premolar and molar teeth. Moreover, the combination of both methods produces the best effect compared to nano-hydroxyapatite or ozone therapy applied alone. However, the treatment should be continued for a long time in order to achieve nonrestorative recovery of caries.

Cost-Effectiveness through the Dental-Health FRAMM Guideline for Caries Prevention among 12- to 15-Year-Olds in Sweden

Since 2008, FRAMM has been a guideline for caries prevention for all 3- to 15-year-olds in the Västra Götaland Region in Sweden and a predominant part is school-based fluoride varnish applications for all 12- to 15-year-olds. The aims were to evaluate dental health-economic data among 12- to 15-year-olds, based on the approximal caries prevalence at the age of 12, and to evaluate cost-effectiveness. Caries data for 13,490 adolescents born in 1993 who did not take part and 11,321 adolescents born in 1998 who followed this guideline were extracted from dental records. Those with no dentin and/or enamel caries lesions and/or fillings on the approximal surfaces were pooled into the “low” subgroup, those with 1–3 into the “moderate” subgroup and those with ≥4 into the “high” subgroup. The results revealed that the low subgroup had a low approximal caries increment compared with the moderate and high subgroups during the 4-year study period. In all groups, there were statistically significant differences between those who took part in the guideline and those who did not. The analysis of cost-effectiveness revealed the lowest incremental cost-effectiveness ratio (ICER) for the high subgroup for decayed and/or filled approximal surfaces (DFSa) and approximal enamel lesions together and the highest ICER for the low subgroup for DFSa alone. To conclude, the FRAMM Guideline reduced the caries increment for adolescents with low, moderate and high approximal caries prevalence. The subgroup with the most favourable cost-effectiveness comprised those with a high caries prevalence at the age of 12.

Clinical performance of the near-infrared imaging system VistaCam iX Proxi for detection of approximal enamel lesions

Objectives/Aims:Apart from the visual detection of caries, X-rays can be taken for detection of approximal lesions. The Proxi head of VistaCam iX intraoral camera system uses near-infrared light (NIR) to enable caries detection in approximal surfaces. The aim of this study was to evaluate the performance of the NIR for the detection of approximal enamel lesions by comparison with radiographic findings.Materials and methods:One hundred ninety-three approximal surfaces from 18 patients were examined visually and using digital radiographs for presence or absence of enamel lesions. Then digital images of each surface were produced using the near-infrared light. Correlation between methods was assessed using Spearman’s rank correlation coefficient (rs). Agreement between radiographic and NIR findings was calculated using the kappa coefficient. McNemar’s test was used to analyse differences between the radiographic and NIR findings (α=0.05).Results:Moderate correlation was found between all detection methods (rs=0.33–0.50, P<0.0001). Agreement between the radiographic and NIR findings was moderate (κ=0.50, 95% CI=0.37–0.62) for the distinction between sound surfaces and enamel caries. No significant differences were found between the findings (P=0.07).Conclusion:Radiographs and NIR were found to be comparable for the detection of enamel lesions in permanent teeth.

Caries Incidence in a Healthy Young Adult Population in Relation to Diet.

In the past, epidemiological studies focused on cavitated stages of caries. The arrival of the International Caries Detection and Assessment System (ICDAS) in 2004 allowed for clinical measurements of the initial stages of enamel caries. However, since the introduction, most studies applying the ICDAS still have studied the diseased population. The objective of this cross-sectional observational study was to describe early enamel caries in a large healthy young adult population and determine the relationship with diet and oral hygiene measures. The study population consisted of 268 healthy participants without frank cavitation. The examinations were done visually and radiographically using ICDAS on all tooth surfaces. In total, 8.6% of the surfaces (occlusal > approximal > smooth) had caries, of which 92.0% were confined to enamel (28.5% ICDAS score 1, 54.0% score 2, 8.6% score 3). Thirteen percent of the occlusal and 63% of the approximal caries were found with radiography. Thus, radiography is quintessential for the diagnosis of approximal enamel lesions. We found a positive correlation between enamel caries (ICDAS 1 to 3) and the consumption of mono- and disaccharides and carbohydrates ( r = 0.226 and r = 0.188, respectively, both P < 0.01), as well as a negative correlation with alcohol consumption ( r = -0.202, P < 0.01). There was also a positive correlation between enamel caries and the energy intake from mono- and disaccharides (sugar kJ, r = 0.206, P < 0.01), which was independent of body mass index. Only 11 participants consumed less than 10% of total energy as sugar kJ, which is the recommended percentage of kJ from free sugar by the World Health Organization. No clear correlation was found with oral hygiene. In conclusion, in this healthy young adult population, caries was found in 97.8% of the subjects, mostly initial enamel caries (ICDAS 1 to 2) in the occlusal surface of molars, and was related with dietary factors.

Approximal caries increment in relation to baseline approximal caries prevalence among adolescents in Sweden with and without a school-based fluoride varnish programme.

Approximal surfaces are a focal point for caries prevention among adolescents in Sweden and the aims of this study were therefore to evaluate approximal caries incidence and caries progression among adolescents with and without a three-year school-based fluoride varnish programme in relation to approximal caries prevalence at baseline. In all, 758 (89%) 13-year-olds completed the three-year randomised controlled trial. They all used fluoride toothpaste at home and had regular dental check-ups at the public dental clinics. The mean approximal caries incidence for the adolescents who were caries free on these surfaces at baseline was 0.13 (SD 0.54) in the fluoride varnish group and 0.79 (1.93) in the control group. The corresponding values for those who had caries at baseline in these groups were 1.29 (2.21) and 2.62 (3.22) respectively. The latter two groups also had 0.34 (1.00) and 0.70 (1.13) approximal enamel lesions that progressed. All differences were statistically significant (p⟨0.001). Among those individuals who had approximal caries at baseline, double the number of early approximal enamel lesions in the control group progressed compared with the fluoride varnish group. The school-based fluoride varnish programme inhibited new approximal lesions to a great extent and effectively kept approximal enamel lesions within the enamel among 13-16-year-olds. It is therefore recommended that such a programme is warranted when the approximal surfaces are still caries free in order to keep these surfaces free from caries and keep upcoming approximal enamel lesions within the enamel.

Approximal Caries Detection by DIFOTI:In VitroComparison of Diagnostic Accuracy/Efficacy with Film and Digital Radiography

The aim of the present study was to compare the diagnostic accuracy/efficacy of digital imaging fiber-optic transillumination (DIFOTI) with film and digital radiography, in detection of approximal caries lesions. One hundred and twelve approximal surfaces were scored for caries, using DIFOTI images film and digital radiographs. All three sets of images were examined twice by 8 observers, with a minimal interval of one week between examinations. Validation of histological sections served as a reference standard. Reproducibility, based on intra- and interobserver agreement, was similar for all three methods. At diagnostic threshold D1 (enamel and dentin caries), DIFOTI showed significantly higher sensitivity, but differences in specificity between methods were nonsignificant. Diagnostic accuracy in the form of area under the receiver operating characteristic curve (AUC) was significantly higher for DIFOTI. At diagnostic threshold D3 (dentin caries), the differences in sensitivity and AUC among methods were nonsignificant, but DIFOTI showed significantly lower specificity. Compared with the radiographs, DIFOTI showed closer agreement, expressed as weighted kappa values, with the reference standard. The results show that under in vitro conditions, the diagnostic accuracy of DIFOTI in detecting early approximal enamel lesions is greater than that of film and digital radiography, while the potential for detecting lesions in dentin is similar for all three methods.

Incidence and progression of approximal carious lesions among school children in Western Australia

An understanding of carious lesion behaviour is important in timing and frequency of radiographic examinations. The aim of this study was to examine the occurrence and behaviour of approximal enamel lesions in permanent teeth among children in Western Australia and test the effect of easily measured factors on the rate of lesion progression. Bitewing radiographs of children enrolled with the School Dental Service in Western Australia were scored for the occurrence and progression of enamel caries using established criteria. Time to lesion occurrence was estimated by the use of the Kaplan-Meier analysis, bivariate tests of survival functions were undertaken using the log rank test and the influence of the measured factors were tested using the multivariate Cox proportional hazard model. The median time to occurrence of enamel caries was 6.1 months; median time to dentine caries was 77.7 months. Multivariate analysis shows gender (hazard ratio, male 0.65), baseline permanent tooth caries experience (hazard ratio 1.15) and time at risk since eruption (hazard ratio 0.88) were important factors in the initiation of enamel caries while time since eruption (hazard ratio 0.87), clinician's rating of risk (hazard ratio, moderate risk 2.78, high risk 5.00) and residence in fluoridated area (hazard ratio, fluoridate 0.44) were all statistically significant for enamel caries progression. Time to occurrence of enamel lesions in approximal surfaces is relatively rapid while progression into dentine is relatively slow. Clinicians were able to assign the risk of lesion progression in a child. Residence in a fluoridated area has a marked retarding effect on enamel lesion progression but not on initiation of enamel lesions. These factors may be useful in developing a schedule for timing and frequency of radiographic examinations among children in Western Australia.

Detection of Approximal Caries by Clinical and Radiographic Examination in 9-Year-Old Swedish Children

The aims were to determine caries prevalence in 9-year-olds belonging to a low-caries prevalence population and to assess how accurately some commonly used risk factors/risk markers (predictors) can identify additional approximal caries as judged from bitewing examination (BW). One calibrated dentist examined 117 consecutive 9-year-olds from the inner city of Stockholm. The predictors were the number of clinically detected dfs and DFS, visible plaque, salivary mutans streptococci, tooth brushing habits, consumption of sugary products, parents’ education, and (before BW) an overall clinical judgement by the examiner. Analyses of the data included sensitivity and specificity and a multiple logistic regression model. When BW was included, the mean DFS was 0.27 and the mean dfs 1.74. For approximal enamel and dentin lesions, the average gain from BW was 0.20 lesions for permanent first molars and 1.23 lesions for primary molars. Altogether, 48% of the children benefited from BW. The best predictors of additional approximal caries from BW were presence of caries (cavitation/dentin level) on occlusal surfaces of permanent first molars and the dentist’s judgement based on clinical findings, both with a combined sensitivity and specificity of 134%. The only statistically significant variables in a logistic regression model were the dentist’s judgement and the child’s statement about regular tooth brushing. It is concluded that a sizeable proportion of 9-year-olds, representing a low-caries prevalence population, benefited from BW. However, the ability to identify these children from the predictors was limited.

Approximal Caries Development in Adolescents with Low to Moderate Caries Risk after Different 3-Year School-Based Supervised Fluoride Mouth Rinsing Programmes

The aim was to evaluate a 3-year randomised controlled trial of school-based fluoride mouth rinsing (FMR) on approximal caries development in 13- to 16-year-olds with low to moderate caries risk. The adolescents used F toothpaste at home and underwent prophylactic treatment at yearly check-ups at public dental clinics. Out of 788 randomly selected 13-year-olds, 622 completed the trial, carried out in 1999–2003. Supervised by a dental nurse, the subjects rinsed with a 0.2% NaF solution at different intervals. Group 1 rinsed their teeth on the first three schooldays every semester; group 2 on the first three and the last three schooldays every semester; group 3 on three consecutive days once a month during semesters; group 4 once every fortnight during semesters, and group 5 (control) did not rinse. Radiographic recording of approximal caries was performed. FMR on the three first and the three last schooldays every semester (group 2) had a prevented fraction of 59%, with approximal enamel lesions as a diagnostic threshold. Corresponding figures for groups 1, 3 and 4 were 30, 47 and 41%, respectively. The control group differed statistically from groups 2–4 for new enamel and dentin lesions and fillings (p < 0.01). Enamel lesions constituted more than 90% of the new caries lesions. Caries progression was low for all groups and no significant differences were found between groups. The main conclusion from this randomised controlled trial is that school-based FMR, as a supplement to the daily use of F toothpaste, reduces caries incidence on approximal surfaces in adolescents with low to moderate caries risk.

A 2-year clinical evaluation of sealed noncavitated approximal posterior carious lesions in adolescents

The objective was to evaluate the clinical performance of a therapeutic sealant to arrest the progression of noncavitated approximal posterior carious lesions. The study population comprised 50 adolescents in whom bitewing radiographs had been taken for diagnosis of caries. Approximal noncavitated lesions in premolars and molars (4d-7m) were selected. One group (n=17) had a sealant placed after tooth separation on all enamel lesions. A second group (n=7) received sealant and fluoride varnish in a split-mouth design. A control group (n=26) received a standard fluoride varnish treatment without tooth separation. Follow-up radiographs were taken after 2 years and were analyzed together with the baseline radiographs in a blind study setting. About 93% of the sealed initial carious lesions showed no progression. The corresponding value for the fluoride varnish control group was 88%. In the split-mouth study, 92 and 88% of the surfaces with enamel caries showed no progression after sealant or fluoride varnish treatment, respectively. The difference between the two treatment procedures was not statistically significant. The incidence rate for the transition from enamel caries to dentin caries or fillings was 3.5-3.9 surfaces/100 years in the sealant groups and 5.9-6.1 surfaces/100 years in the fluoride varnish groups. The results show the potential of sealants to act as a noninvasive treatment of early approximal enamel lesions.

Influence of the application time on the penetration of different dental adhesives and a fissure sealant into artificial subsurface lesions in bovine enamel

Sealing of approximal enamel lesions by infiltration with low viscous resins seems to be a promising approach in non-operative dentistry and should bear advantages compared to remineralization or invasive treatment. The aim of this in vitro study was to evaluate the penetration ability of five dental adhesives and a fissure sealant into initial enamel lesions for an application time of either 15 s or 30 s. In each of 54 specimens of bovine enamel, three windows were demineralized for 14 days. Subsequently, two windows were etched with phosphoric acid for 5s in order to degrade the surface layer, whereas one window served as untreated control. The specimens were randomly divided into six groups and a fissure sealant as well as five different adhesives were applied onto the subsurface lesions and allowed to penetrate for either 15 or 30 s. Overlying material was wiped away and the resins were light cured. To visualize the penetrated resins and the remaining pore structures, the specimens were infiltrated with a low viscous fluorescent resin and studied using a Confocal Laser Scanning Microscope (CLSM). For Helioseal, Heliobond, Resulcin Monobond, and Excite an application time of 30s resulted in significantly higher (p < 0.05; t-test) penetration depths (47-105 microm) compared to 15s (29-49 microm). Helioseal, Heliobond, Resulcin Monobond, and Excite are suitable for sealing artificial subsurface enamel lesions in vitro. After an application time of 30 s a significant deeper penetration could be observed for these materials.

Detection of Approximal Caries in 5-Year-Old Swedish Children

The aim was to assess how accurately some commonly used risk factors/risk markers (predictors) for caries development could identify children with and without approximal caries as judged from bitewing radiography. Two hundred and sixty-seven consecutive 5-year-old children from two Swedish cities participated. Three experienced dentists examined the children. The predictors were the overall dmfs (decayed, missing and filled surfaces) value (canines and molars), the number of occlusal dmfs, the frequency of intake of between-meal sugary products, visible plaque on free smooth surfaces of second primary molars, toothbrushing habits and (before bitewing examination) an overall judgement by the examining dentist. The mean dmfs value without bitewing examination was 0.40 (SD = 1.22). Twelve percent of the children had at least one dentin lesion and 33% at least one enamel lesion that were detected from bitewing examination only. The gain from adding bitewing examination to clinical examination amounted to a mean of 1.2 approximal enamel and/or dentin lesions. The ability to correctly identify children with approximal caries from the predictors was limited; sensitivity ranged from 0.27 to 0.75 and specificity ranged from 0.41 to 0.93. The single best predictor was the dentist’s overall judgement with an average precision of 73%; average sensitivity for the presence of enamel and dentin lesions was 0.48 and for the presence of dentin lesions 0.66. The rest of the predictors added little to the predictive power. It is concluded that 33% of the 5-year-olds, representing a low caries prevalence population, benefited from bitewing examination. The ability to identify these children from the predictors was, however, limited.

Radiographic prevalence of approximal enamel lesions and relationship with dentine lesions and restorations in Dutch adolescents

The aim of this study was to assess the prevalence of approximal enamel lesions from radiographs in groups of 14, 17, 20 and 23 years old, and to determine the relation with dentine lesions and restorations present. Per age group, the bitewings of 120 persons were randomly selected and assessed for enamel lesions from the distal surface of the first premolar to the mesial surface of the second molar. A second examiner assessed 20% of the material for enamel lesions to determine the interexaminer agreement (Cohen's kappa = 0.63). An enamel lesion was found in 12-15% of the unfilled surfaces. The mean number of surfaces with enamel lesions was almost three per person. For all age groups it was found that about 20% of the persons had at least four enamel lesions and the number of enamel lesions was significantly correlated with the number of dentine lesions. Of all enamel lesions 20% were found in persons without any dentinal lesions or restorations. The bitewing radiographs showed a considerable number of enamel lesions for these age groups. This seems to justify its use on a routine base as a diagnostic tool at the age of 14-16 years.

Incidence and Progression of Approximal Caries from 11 to 22 Years of Age in Sweden: A Prospective Radiographic Study

Using annual bite–wing radiographs, the incidence and progression of approximal caries (4d–7m) were assessed longitudinally in teenagers and adolescents whose treatment had been based on remineralizing rather than restorative strategies. A closed cohort of 536 children initially was followed from 11 to 22 years of age. The scoring system was: 0 = no visible radiolucency; 1–2 = radiolucency in the enamel up to the enamel–dentin border; 3 = radiolucency with a broken enamel–dentin border but with no obvious progression in the dentin; 4 = radiolucency with obvious spread in the outer half of the dentin, and 5 = radiolucency in the inner half of the dentin. Caries rates were estimated as the number of new lesions/100 tooth surface–years, and the Kaplan–Meier estimate was used to calculate the cumulative survival time of each approximal surface. Three events were used: the transitions from states 0 to 2, 2 to 4 and 3 to 4. The results showed a considerable variation between the surfaces in both caries rates and survival time. For all surfaces combined, the median caries rate from state 0 to 2 was 3.9 new lesions/100 tooth surface–years; from state 2 to 4, the rate was 5.4, and from state 3 to 4 it was 20.3. Of the sound surfaces (state 0), 75% survived 6.3 years without reaching state 2. Given state 2, 75% survived 4.8 years without reaching the outer half of the dentin (state 4), while given a lesion at the enamel–dentin border (state 3), 75% survived 1.3 years without doing the same. The median survival time of lesions from state 3 to 4 was 3.1 years. The group with DMFS_appr>1 at the age of 11–12 years had a risk of new approximal enamel lesions (state 0–2) that was 2.5 times greater than that of the group with DMFS_appr = 0–1.

A structural analysis of approximal enamel caries lesions and subjacent dentin reactions.

The present study examines the correlation between caries lesions in enamel and the corresponding dentin reactions in proximal tooth surfaces with lesions ranging from enamel lesions to cavitations without dentin exposure. Using quantitative imbibition technique, the highest degree of tissue porosity, irrespective of lesion activity, was always noted along a Central-Traverse (CT), which followed the direction of the rods from the deepest point of penetration to the surface. The conical shape of approximal enamel lesions can thus be seen as the result of systematic variations in porosity along the rods determined by the specific interproximal environment. The initial dentin reaction, related to the enamel lesion approaching the enamel-dentin junction (EDJ), was seen as a local dentin translucency where the CT crossed the EDJ. Results from histomorphometric analyses revealed that, when the enamel lesions reached the EDJ, brownish discoloration in the dentin never exceeded the histologic contact area between the enamel lesion and the EDJ. In relation to the less advanced parts of the individual enamel lesion, the dentin responded with formation of translucent dentin. These reactions did not occur beyond an area determined by lines in the direction of the rods from the peripheral part of the enamel lesion towards the EDJ. The results did not support the view that dentin caries spreads along the enamel-dentin junction. The peripheral dentin translucency is therefore generated by stimuli transmitted along the rods of the less advanced parts of the enamel lesions.

Prediction of caries incidence in schoolchildren living in a high and a low fluoride area

A salivary mutans streptococci test and past caries experience were used as predictors for caries increment in a 3-yr study comprising 655 12-yr-old schoolchildren from two areas with contrasting levels of fluoride in the drinking water. The mean caries (DMFS) increment was similar in both groups during the study period, but a significantly (P < 0.05) higher incidence of approximal enamel lesions was registered in children from the high fluoride area. In both groups, a statistically significant (P < 0.05-0.001) positive relationship between salivary mutans streptococci score and/or past caries experience at baseline on one hand and caries increment during the study period on the other was established. The past caries experience was the most powerful predictor of caries risk in both the low fluoride and the high fluoride area. The sum of the sensitivity and specificity was somewhat higher in the low fluoride area (138%) compared to the high fluoride area (123%). The salivary bacterial enumeration used alone or in combination with past caries experience as well as past approximal caries experience were less useful as predictors in both groups. The present findings indicate that the natural fluoride exposure has a limited influence on caries risk assessment and the caries predictive ability of the salivary bacterial test and past caries in populations with a low level of disease.