Caries assessment and restorative treatment thresholds reported by Swedish dentists.

The aim was to study any variability in approximal and occlusal caries diagnoses and restorative treatment decisions among Swedish dentists. The material consisted of a pre-coded questionnaire sent to a random sample of 923 dentists with 4 items concerning approximal and occlusal caries diagnosis and restorative treatment decisions. Responses were received from 651 (70.5%) dentists. In an adolescent with low caries activity and good oral hygiene, more than 90% of the dentists stated that they would not automatically restore a primary approximal caries lesion if its radiographic appearance did not show obvious progression in the outer 1/3 to 1/2 of the dentin. Moreover, 67% of the dentists would only consider immediate restorative treatment of an occlusal surface if obvious cavitation and/or radiographic signs of dentin caries could be observed. When diagnosing questionable occlusal caries, the dentists largely relied on the radiographic appearance. Concerning both approximal and occlusal caries, the threshold for restorative treatment differed between the metropolitan regions in Sweden, and younger more often than older dentists would postpone restorative treatment of approximal caries until the lesion had reached a relatively advanced stage of progression. The responses also showed that dentists in private practice would restore approximal caries at an earlier stage of progression than the dentists in the Public Dental Health Service.     

Sealants and dental caries: dentists' perspectives on evidence-based recommendations

BackgroundThe authors conducted a study to survey the perspectives of dentists regarding the 2010 American Dental Association (ADA) recommendation to seal non-cavitated carious lesions (NCCLs) in children and young adults.MethodsThe authors mailed a questionnaire to a randomly selected sample of 2,400 general dentists (GDs) and pediatric dentists (PDs) in the United States. The sample was chosen by the ADA&;apos;s Survey Center. The questionnaire included two photographs of NCCLs (permanent first molar and premolar) in a 12-year-old child. Respondents were provided with radiographic findings and asked to choose from several management options.ResultsIn the absence of radiographic evidence of caries, 37.4 percent and 42.3 percent of GDs and PDs, respectively, indicated that they would seal the NCCL in the molar. For the premolar, a significantly lower percentage of GDs than of PDs indicated that they would seal the NCCL. With radiographic evidence of caries in dentin, less than 4 percent of all dentists surveyed indicated that they would seal the NCCLs, and more than 90 percent indicated that they would remove the caries and place restorations. Less than 40 percent of dentists indicated that they sealed NCCLs in their practice.ConclusionsThe U.S. dentists surveyed have not adopted evidence-based clinical recommendations regarding the sealing of NCCLs.Practice ImplicationsNew educational and dissemination programs should be developed regarding these evidence-based caries management approaches.     

Reasons for Placement of Restorations on Previously Unrestored Tooth Surfaces by Dentists in The Dental Practice-Based Research Network

ObjectiveThe authors conducted a study to identify and quantify the reasons used by dentists in The Dental Practice-Based Research Network (DPBRN) for placing restorations on unrestored permanent tooth surfaces and the dental materials they used in doing so.MethodsA total of 229 DPBRN practitioner-investigators provided data from their practices regarding 9,890 consecutive restorations in 5,810 patients. Information the practitioner-investigators provided included their reasons for restoring the teeth, the specific teeth and surfaces they restored and the restorative materials they used.ResultsPrimary caries (85 percent of teeth, 8,351 of 9,890) and noncarious defects (15 percent, 1,479 of 9,890) were the main reasons participants gave for placing restorations. Participants placed restorations necessitated by caries most frequently on occlusal surfaces (49 percent, 4,091 of 8,351). They used amalgam for 47 percent of the molar restorations and 45 percent of the premolar restorations. They used directly placed resin-based composite (RBC) for 48 percent of the molar restorations, 50 percent of the premolar restorations and 93 percent of the anterior restorations.ConclusionDPBRN practitioner-investigators cited dental caries on occlusal and proximal surfaces of molar teeth as the main reasons for placing restorations on previously unrestored tooth surfaces. RBC was the material they used most commonly for occlusal and anterior restorations. Amalgam remains the material of choice to restore posterior teeth with proximal caries, although the authors noted significant differences in the use of amalgam and RBC by dentists in various regions of the DPBRN.     

Swedish dentists' decisions on preparation techniques and restorative materials

This study aimed at mapping the preparation techniques and restorative materials that Swedish dentists are using for primary approximal and occlusal carious lesions. It involved sending a pre-coded questionnaire to a random sample of 923 dentists, with eight items concerning approximal and occlusal restorative preparation techniques and dental materials. Responses were received from 651 (70.5%) dentists. To restore a primary approximal carious lesion in an adolescent with low caries activity and good oral hygiene, the tunnel preparation was chosen by 48% of the dentists, the saucer-shaped preparation by 32%, and the traditional Class II preparation by 20%. The most common preparation technique for restoring an occlusal carious lesion was removal of the carious part only, which was chosen by 74% of the dentists. For a lower second molar with a minor occlusal caries lesion combined with a suspected dentin lesion as judged radiographically, about half of the dentists chose to restore the carious part only and 27% would seal the rest of the fissure system in addition. For a similar lesion with no obvious radiolucency in the dentin, about 1/3 chose the 'no treatment' alternative, 1/3 fluoride treatment, and the rest fissure sealing or other techniques. Composite was used most often and amalgam least often for both approximal and occlusal carious lesions.     

Management of initial carious lesions: Iowa survey

BackgroundThe authors explore Iowa dentists’ agreement with the International Caries Classification and Management System (ICCMS) in the nonsurgical management of initial carious lesions in patients at low, moderate, and high caries risk and identify factors related to their agreement.MethodsElectronic surveys were mailed to 916 actively practicing dentists who are alumni of the College of Dentistry at The University of Iowa. Questions included clinical scenarios that used text, clinical photographs, and radiographic images of initial carious lesions. Dentists were asked what type of treatment they would recommend. Treatment options included no treatment, nonsurgical treatment, or surgical treatment. Logistic regression analyses were used to assess associations among agreement with ICCMS, characteristics of the dentist’s practice, and patients’ caries risk level.ResultsA total of 138 Iowa dentists responded to the survey. Agreement with ICCMS regarding nonsurgical management of initial carious lesions for patients at low, moderate, and high risk levels were 73%, 59%, and 51% respectively. Compared with their counterparts, dentists who agreed with the recommendations for nonsurgical treatment were more likely to dry the teeth during caries detection (95% confidence interval [CI], 1.02 to 12.67, P = .0468), use magnification (95% CI, 1.16 to 7.17, P = .0225) for caries detection, have graduated less than 20 years ago (P = .0024), practice in public health settings (P = .0089), and perform a caries risk assessment (95% CI, 1.10 to 4.29, P = .0262).ConclusionsDentists who dry teeth, use magnification for caries detection, graduated in the past 20 years, practice in a public health setting, and perform a caries risk assessment were significantly more likely to make decisions that were consistent with the guidelines of the ICCMS.Practical ImplicationsKnowledge of evidence-based options personalized for a patient’s risk status is essential for applying the best management of initial caries lesions.     

Swedish dentists' decisions on preparation techniques and restorative materials

This study aimed at mapping the preparation techniques and restorative materials that Swedish dentists are using for primary approximal and occlusal carious lesions. It involved sending a pre-coded questionnaire to a random sample of 923 dentists, with eight items concerning approximal and occlusal restorative preparation techniques and dental materials. Responses were received from 651 (70.5%) dentists. To restore a primary approximal carious lesion in an adolescent with low caries activity and good oral hygiene, the tunnel preparation was chosen by 48% of the dentists, the saucer-shaped preparation by 32%, and the traditional Class II preparation by 20%. The most common preparation technique for restoring an occlusal carious lesion was removal of the carious part only, which was chosen by 74% of the dentists. For a lower second molar with a minor occlusal caries lesion combined with a suspected dentin lesion as judged radiographically, about half of the dentists chose to restore the carious part only and 27% would seal the rest of the fissure system in addition. For a similar lesion with no obvious radiolucency in the dentin, about 1/3 chose the 'no treatment' alternative, 1/3 fluoride treatment, and the rest fissure sealing or other techniques. Composite was used most often and amalgam least often for both approximal and occlusal carious lesions.     

Management Thresholds for Molars With Occlusal Noncavitated Caries Lesions

AimThere is sparse research on the effect of factors related to the dentist and patient in the caries management decision-making process. This in vitro study explored the influence of factors related to dentists and patients on the management decision of occlusal noncavitated caries lesions in children.Materials and methodsFive investigators in the specialties of dental public health (DPH), paediatric, prosthetic, and operative dentistry and a general dentist (GDP) participated in this study. Initially, the investigators were asked to independently assess the occlusal surfaces of 175 noncavitated permanent molars and choose a management recommendation using 2 caries risk patients’ scenarios. After 1 month, investigators were trained and calibrated to use the International Caries Detection and Assessment System (ICDAS) scoring system. Then, they examined the same teeth, recorded the highest/worst ICDAS score, and chose a management recommendation. Two weeks later, the investigators repeated the teeth examination using magnification loupes and again chose a management recommendation. The teeth were sectioned to study the relationship between the presence of caries and the management recommendations.ResultsFor the low– and the high–caries risk scenarios, ICDAS training increased the operative intervention by 20% to 27% and 14% to 22%, respectively, for both the GDP and the paediatric dentist (P < .0001). For the low–caries risk scenario, using the magnifying loupes increased the operative recommendations for the DPH, GDP, and the operative dentist by 5% to 23% (P < .05). Compared to the low–caries risk scenario, teeth for patients with high caries risk received more surgical interventions (9%-30%) at all examination conditions for the GDP and the paediatric and operative dentists (P < .0001).ConclusionsFor occlusal noncavitated caries lesions, enhancing dentists’ caries detection skills had a significant impact on decisions of surgical intervention. This also influenced the appropriateness of the treatment recommended for the different caries risk groups.     

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.     

Validation of swept source optical coherence tomography (SS-OCT) for the diagnosis of smooth surface caries in vitro

ObjectiveAn accurate evaluation of the extent of dental caries and possible progress of the lesion from enamel into dentin is very important in clinical dentistry. Dentists need an imaging technology that can noninvasively and reliably quantify the extent of caries. This study aimed to evaluate the effectiveness of non-polarized swept source optical coherence tomography (OCT) in evaluating the extent of caries on smooth enamel surfaces.MethodsOne-hundred and twenty-seven investigation sites on the enamel surfaces of 93 extracted teeth were selected randomly and examined visually. The presence and extent of caries were scored by experienced and inexperienced dentists using each observation method (0: no caries; 1: enamel demineralization without surface breakdown; 2: enamel breakdown due to caries; 3: deep caries involving the dentin). The same locations were then examined using OCT, following which the teeth were sectioned using a diamond saw and viewed directly under a confocal laser scanning microscope (CLSM). Sensitivity and specificity indices for OCT and VI were calculated and compared. The results were analysed statistically using receiver operating characteristic (ROC) curves.ResultsEnamel and dentin caries were outlined by a visible boundary on the cross-sectional OCT images. The modality showed superior results for the detection of dentinal caries; higher sensitivity and Az values could be obtained in the ROC curves, especially by experienced dentists.ConclusionsCross-sectional imaging of the natural caries lesions on smooth enamel surface by OCT enables efficient diagnosis of the lesion type, extent and dentin involvement.Clinical significanceSS-OCT can demonstrate the cross-sectional image of smooth surface enamel caries as highlighted zone in tomogram. It is crucial to determine the extent of the lesion, whether it reaches beyond DEJ or not by a non-invasive and safe technique. OCT can give clinicians information about internal tooth structure and will help clinical decision making on surgical intervention.     

A comparison of radiographic occlusal and approximal caries diagnoses made by 240 dentists

Radiographs of occlusal (n = 20)and approximal (n = 24)surfaces of extracted teeth were examined by 240 dentists before participating in continuing education courses dealing with caries diagnosis and treatment decisions. The radiographic caries diagnoses were treated in accordance with the receiver operating characteristic (ROC) technique, in which the area beneath the ROC curve (A_z value) indicates the quality of the observations. The frequencies of false positives made in dentin radiographically were higher for approximal (20.7%) than for occlusal caries (12.3%). The quality of pooled radiographic diagnoses of occlusal dentin lesions for all observers was significantly better than diagnoses of approximal caries in dentin. A statistically significant relationship between the observer's qualities of diagnosis of caries on approximal and occlusal surfaces (P = 0.045) was found. For diagnosis of dentin caries on approximal surfaces the mean Cohen kappa was 0.74 (standard deviation (s), 0.12; range, 0.39-0.95), and the corresponding values for occlusal surfaces were 0.70 (s, 0.14; range, 0.25-0.98). In the material under study the dentists were at least as good at diagnosing dentin caries occlusally as approximally. To avoid overtreatment, the observer's diagnostic threshold should ideally be adjusted towards strict criteria when a positive diagnosis is synonymous with a filling. The diagnostic thresholds were stricter in diagnosing occlusal surfaces than for approximal surfaces, indicating a more optimal strategy among dentists while diagnosing occlusal dentin lesions in a population with low caries prevalence.     

Differences between reported and actual restored caries lesion depths: results from The Dental PBRN

ObjectiveThe objectives of this research were to (1) quantify the discordance between the caries lesion depth at which dentists restored initial lesions during a clinical study (“actual depth”) and the lesion depth that they reported during a hypothetical clinical scenario (“reported depth”); (2) test the hypothesis that certain practitioner, practice, patient, and caries lesion characteristics are significantly associated with this discordance.MethodsPractitioner-investigators who perform restorative dentistry in their practices completed an enrollment questionnaire and participated in two consecutive studies on caries diagnosis and treatment. The first study was a survey asking about caries treatment. The second study collected data on restorations placed in routine clinical practice due to caries in patients over 19 years of age on occlusal surfaces only or proximal surfaces only. We report results on 2691 restorations placed by 205 dentists in 1930 patients with complete data.ResultsDiscordance between actual depth and reported depth occurred in only about 2% of the restorations done due to proximal caries, but about 49% of the restorations done due to occlusal caries. Practice type, restorative material used and the diagnostic methods used were significantly associated with discordance.ConclusionDentists frequently restored occlusal caries at a shallower depth as compared to their reported depth, but the discordance was very small for proximal lesions. Discordance for occlusal caries was more common when radiographs were not taken or if a resin restoration was placed.     

A comparison of radiographic occlusal and approximal caries diagnoses made by 240 dentists.

Radiographs of occlusal (n = 20) and approximal (n = 24) surfaces of extracted teeth were examined by 240 dentists before participating in continuing education courses dealing with caries diagnosis and treatment decisions. The radiographic caries diagnoses were treated in accordance with the receiver operating characteristic (ROC) technique, in which the area beneath the ROC curve (A, value) indicates the quality of the observations. The frequencies of false positives made in dentin radiographically were higher for approximal (20.7%) than for occlusal caries (12.3%). The quality of pooled radiographic diagnoses of occlusal dentin lesions for all observers was significantly better than diagnoses of approximal caries in dentin. A statistically significant relationship between the observer's qualities of diagnosis of caries on approximal and occlusal surfaces (P = 0.045) was found. For diagnosis of dentin caries on approximal surfaces the mean Cohen kappa was 0.74 (standard deviation (s), 0.12; range, 0.39-0.95), and the corresponding values for occlusal surfaces were 0.70 (s, 0.14; range, 0.25-0.98). In the material under study the dentists were at least as good at diagnosing dentin caries occlusally as approximally. To avoid overtreatment, the observer's diagnostic threshold should ideally be adjusted towards strict criteria when a positive diagnosis is synonymous with a filling. The diagnostic thresholds were stricter in diagnosing occlusal surfaces than for approximal surfaces, indicating a more optimal strategy among dentists while diagnosing occlusal dentin lesions in a population with low caries prevalence.     

Is the morphology and activity of the occlusal carious lesion related to the lesion progression stage?

ObjectiveTo investigate the relationship between degree of dentin demineralization with both lesion activity and morphology of the occlusal carious cavity.DesignOcclusal sites (n = 138) were identified by visual examination (Nyvad’s scores 0–6) in 67 extracted teeth which were scanned in a high energy micro-CT. After 3D reconstruction, each stack was resliced in the mesio-distal direction and tooth mineral density (MD) was measured along a path from enamel to the deepest part of dentin in the slice showing the most severe carious involvement. Each site was classified in “open” or “closed” (if cavitated) depending on the morphology of the surrounding enamel walls as measured using micro-CT and as active or inactive in enamel or dentin by a clinical scoring system.ResultsLesions showing dentin cavitation presented higher demineralization degree compared to non-cavitated, or enamel cavitated lesions. Inactive lesions presented lower demineralization degree compared to active lesions, although with a low effect size. According to the morphological aspect of the carious cavity, open enamel lesions showed lower dentin demineralization degree than closed lesion environments.ConclusionActive lesions showed higher dentin demineralization degree than inactive ones, while lesions showing closed cavitation resulted in higher dentin demineralization degree only for enamel lesions. Including those parameters in treatment decisions may help to improve prognosis and increase effectiveness of the caries diagnostic systems in the clinical setting.     

Variation in radiographic interpretation and restorative treatment decisions on approximal caries among dentists in Norway

Of a random sample of dentists in Norway (n = 741), 83% responded to a questionnaire about their use of radiographs in and their opinions and knowledge about the diagnosis of approximal caries. There was great disparity in criteria for initiation of restorative treatment of approximal caries based on radiographic appearance. Two thirds of the dentists would do restorative treatment of lesions confined to enamel, the others would wait until lesions had reached the dentin before treatment was commenced. The criteria for restoration based on radiographic appearance was best correlated with the dentists' opinions about cavity formation. About 20% of the variation in criteria among dentists was explained by the radiographic appearance dentists associated wih the presence of a cavity. The majority of the dentists believed that approximal caries progressed faster than is indicated by progression studies. The interval between recall examinations using radiographs was not consistently shorter for dentists who decided to carry out operative caries treatment at a relatively advanced stage.     

Restorative treatment strategies reported by French university teachers

Disparities among dental schools concerning the teaching and practice of cariology and operative dentistry can lead to variations in students' treatment modalities that can have health and economic consequences for patients and third party providers. The purpose of this study was to assess caries management strategies taught in French dental schools employing a questionnaire used in a previous study involving private dentists. The study population consisted of 180 teachers of operative dentistry. Each teacher received a questionnaire and a reply-paid envelope. The questionnaire assessed their treatment strategies, knowledge and beliefs about selected aspects of diagnosis, and treatment of dental caries. After one reminder, the response rate was 49.1 percent. The results illustrate a wide disparity among French teachers concerning restorative treatment thresholds for approximal surfaces, opinions about the rate of caries progression, and the need to monitor lesions near the DEJ. The teachers' attitudes differed from those of private practitioners: they tended to intervene surgically at a later stage, but they would intervene earlier in the treatment of the carious process than would Scandinavian dentists. This study may help in encouraging dental faculties to develop a consensus on issues related to diagnosis and management of dental caries.     

Restorative treatment threshold reported by Iranian dentists

OBJECTIVE: To study Iranian dentists' conceptions of the earliest stage to place a restoration on proximal caries lesions. BASIC RESEARCH DESIGN: A questionnaire survey was carried out among the participants of two annual dental meetings in Tehran, Iran, in December 2004 and July 2005. The questionnaire was filled in anonymously and returned during the meeting days. The questions covered two patient paper cases with schematic drawings of the radiolucency of proximal caries lesions according to bitewing radiographs from 20-year-old patients: one high-caries case and one low-caries case. Dentists' gender, age, working experience and place, and participation in continuing education served as background data. In total, 1,033 dentists completed the questionnaire, 63% were men. Statistical evaluation was by the Chi square test and logistic regression. MAIN OUTCOME MEASURES: Respondents were to select from four alternatives the earliest stage in the progression of a lesion at which they would intervene by restorative treatment. RESULTS: For the high-caries case, 77% of the respondents chose to restore a caries lesion confined to enamel; activity in continuing education was the strongest factor (OR = 1.4) to explain dentists' restoring a lesion no earlier than in dentine. For the low-caries case, 32% chose to restore a lesion in enamel. Restoring a lesion no earlier than in dentine was more likely (OR = 1.5) among female dentists. CONCLUSION: Iranian dentists seem to prefer early restorative intervention, which indicates a need to focus on the preventive aspects of caries treatment both in dental curricula and in continuing education.     

Long-term follow-up of inactive occlusal caries lesions: 4-5-year results

Objective

To assess the clinical behavior of inactive caries lesion on the occlusal sites of permanent molars over 4–5 years and to estimate the risk for progression of caries-inactive sites compared with sound ones.

Methods

Clinical examinations were conducted at baseline (n = 258) and after 4–5 years and included the recording of dental plaque and dental caries at the occlusal surfaces and the eruption stage of each permanent molar.

Results

One hudred ninety-three schoolchildren were followed (response rate of 74.8%), totalizing 1152 teeth. Of the children, 30.6% (n = 59) presented at least one molar containing an active lesion, filling, or that had been extracted; according to the activity criterion, inactive lesions presented around a twofold increased risk for caries progression than sound surfaces (OR = 2.34 95%CI = 1.51–3.62). Thirteen percent (n = 25) of the children presented at least one molar progressing to dentine cavity, filling, or extraction; according to the severity criterion, inactive caries lesions presented a significantly higher risk for progression when compared with sound surfaces (OR = 2.69, 95% CI = 1.50–4.83).

Conclusion

The vast majority of lesions (85–90%) identified as inactive enamel caries at baseline did not progress over 4–5 years. Despite this fact, it was possible to detect an increased risk for caries progression in caries-inactive occlusal sites compared with the sound ones.

Clinical relevance

Considering the low progression rates, inactive caries lesions do not need a specific caries-controlling treatment and should be monitored longitudinally in the same manner as sound surfaces.

     

Caries progression in 12-to 16-year-old schoolchildren in fluoridated and fluoride-deficient areas in Brazil

Abstract Water fluoridation may reduce the rate of caries initiation, but relatively little is known of its effect on rates of caries progression through the enamel and the dentin. Objective: This longitudinal study was designed to compare rates of caries progression in fluoridated and fluoride-deficient areas. Methods: Approximal caries progression was evaluated on two standardized sets of bitewing radiographs taken at a 12-month interval of 290 12- to 16-year-old Brazilian schoolchildren. Pitts' scoring system was used to measure caries progression on conventional bitewing images. Caries progression data on the occlusal, free-smooth, and approximal surfaces of the anterior teeth were collected via clinical visual examinations. Results: The mean rate of approximal caries progression in schoolchildren living in fluoridated areas (0.54) was found to be 62% lower than that in children from fluoride-deficient areas (1.41). When progression rates were adjusted for the initial number of decayed surfaces per subject, differences were statistically significant for lesions located at the inner half of the enamel at baseline (11% in the fluoridated areas vs. 16.5% in the fluoride-deficient areas). Multivariate logistic regression analysis revealed that residence in a fluoride-deficient area remained a significant risk factor for caries progression after controlling for caries prevalence (D₁FS), number of cavitated carious lesions, whether tooth type was molar or premolar, and tooth brushing frequency. Conclusions: These results suggest that water fluoridation reduces the rates of caries progression through the enamel and dentin, but the effect was more pronounced for lesions in the inner enamel than for those in the dentin.     

Influence of 2 caries-detecting devices on clinical decision making and lesion depth for suspicious occlusal lesions: A randomized trial from The National Dental Practice-Based Research Network

Background

A suspicious occlusal carious lesion (SOCL) can be defined as a lesion with no cavitation and no radiographic radiolucency but for which caries is suspected. The authors evaluated whether using a device changed the percentage of SOCLs that were opened surgically and, among those SOCLs that were opened, the proportion that had penetrated into dentin.

Investigations of the optical properties of enamel and dentin for early caries detection

Introduction

The aim of this study was to experimentally investigate the potential of different light wavelengths to distinguish between healthy and carious tissue using a two-circle goniometer.

Materials and methods

Tooth slices were prepared from extracted human teeth that were caries free (n = 15) or had occlusal caries lesions (n = 10). The tooth slices were irradiated with diode laser modules of different wavelengths (532, 650, 780 nm). The transmitted and scattered laser light was spatially measured with a detector rotating on a two-circle goniometer. The anisotropy factor and attenuation coefficients were calculated.

Results

Enamel was more transparent than dentin and showed wavelength-dependent attenuation. Healthy dentin showed strong light scattering at all wavelengths, independent of the tested wavelength. The calculated attenuation coefficients of carious and healthy tooth tissue differed significantly (p < 0.05; t test). In contrast to healthy enamel, carious enamel showed lower light transmission and an increase in scattering. Differences in the light attenuation of carious versus healthy dentin were less pronounced than those for enamel. Carious dentin was slightly more transparent than healthy dentin. The light of longer wavelengths showed a better penetration of all tooth structures compared with shorter wavelengths.

Conclusion

Healthy and carious dentin and enamel exhibited distinct optical properties using laser light at different wavelengths. In dentin, changes in the optical properties caused by caries are significantly less pronounced.

Clinical relevance

The clear distinction between healthy and carious enamel makes optical caries diagnostic systems ideal tools for early caries detection.