Radiographic Caries Diagnosis Research Articles

Attitude, perception and barriers of dental professionals towards artificial intelligence

AimTo know attitudes, perceptions and barriers towards the use of Artificial Intelligence (AI) in dentistry in India among undergraduate and postgraduate students. MethodologyA questionnaire-based cross-sectional study was conducted among participants pursuing graduation and postgraduation. The questionnaire consisted of 23 close-ended and 2 open-ended questions divided into various sections of attitude, perception and barriers. The data was analysed using Statistical Package for Social Sciences (SPSS) version 24.0. ResultOut of 937 responses, 55.2% responded that they get information about AI from social media platforms. 51.3% of respondents have basic knowledge about the use of AI in dentistry. 59.6% agreed that AI can be used as a “definitive diagnostic tool” in the diagnosis of diseases. 66.5% agreed that AI can be used for radiographic diagnosis of tooth caries. 71.3% stated that AI can be used as a “treatment planning tool” in dentistry. 55.7% stated that AI should be part of undergraduate dental training. ConclusionThis study concluded that both dental students are aware of the concept of AI. Participants were positive when asked if AI can increase the efficiency of diagnosis, prognosis and treatment planning procedures as well as in managing patient data. Both participants believed that the barriers to the introduction of AI in dentistry are a lack of technical resources and a lack of training personnel in college.

Radiographic diagnosis of proximal caries is not affected by exposure protocols and presence of high-density material on systems with automatic exposure compensation.

To investigate the performance of radiographic systems with automatic exposure compensation (AEC) on the caries diagnosis in images acquired with different exposure parameters and in the presence of high-density material. Also, the image quality was assessed. Forty posterior teeth (80 proximal surfaces) were radiographed using a phosphor plate and a CMOS system. Images were acquired with different exposure times (0.06, 0.10 and 0.16s) and kilovoltages (60 and 70kVp), in the absence and presence of high-density material in the X-rayed region (control and high-density groups). Five radiologists assessed the caries using a 5-point scale. Diagnostic values were compared using two-way ANOVA. For both radiographic systems, there were no significant differences in the area under the ROC curve (0.60-0.73), sensitivity (0.79-0.87) and specificity (0.29-0.48) between the control and high-density groups, exposure times or kilovoltages (p > 0.05). For image quality, scores assigned to the control and high-density groups were similar in each exposure protocol in both systems. The presence of high-density material, exposure time and kilovoltage did not affect the caries diagnosis in any of the systems tested. It is recommended to use protocols with lower doses to reduce the patient's exposure.

Radiographic modalities for diagnosis of caries in a historical perspective: from film to machine-intelligence supported systems.

Radiographic imaging for the diagnosis of caries lesions has been a supplement to clinical examination for approximately a century. Various methods, and particularly X-ray receptors, have been developed over the years, and computer systems have focused on aiding the dentist in the detection of lesions and in estimating lesion depth. The present historical review has sampled accuracy ex vivo studies and clinical studies on radiographic caries diagnosis that have compared two or more receptors for capturing the image. The epochs of film radiography, xeroradiography, digital intraoral radiography, panoramic radiography and other extraoral methods, TACT analysis, cone-beam CT and artificial intelligence systems aiding in decision-making are reviewed. The author of this review (43 years in academia) has been involved in caries research and contributed to the literature in all the mentioned epochs.

Cerium Dioxide Particles to Tune Radiopacity of Dental Adhesives: Microstructural and Physico-Chemical Evaluation.

The insufficient radiopacity of dental adhesives applied under composite restorations makes the radiographic diagnosis of recurrent caries challenging. Consequently, the misdiagnosis may lead to unnecessary replacement of restorations. The aims of this study were to formulate experimental dental adhesives containing cerium dioxide (CeO2) and investigate the effects of different loadings of CeO2 on their radiopacity and degree of conversion for the first time. CeO2 was characterized by X-ray diffraction analysis, Fourier transforms infrared spectroscopy, and laser diffraction for particle size analysis. Experimental dental adhesives were formulated with CeO2 as the inorganic filler with loadings ranging from 0.36 to 5.76 vol.%. The unfilled adhesive was used as a control. The studied adhesives were evaluated for dispersion of CeO2 in the polymerized samples, degree of conversion, and radiopacity. CeO2 presented a monoclinic crystalline phase, peaks related to Ce-O bonding, and an average particle size of around 16 µm. CeO2 was dispersed in the adhesive, and the addition of these particles increased the adhesives’ radiopacity (p < 0.05). There was a significant decrease in the degree of conversion with CeO2 loadings higher than 1.44 vol.%. However, all materials showed a similar degree of conversion in comparison to commercially available adhesives. CeO2 particles were investigated for the first time as a promising compound to improve the radiopacity of the dental adhesives.

Automatic exposure compensation and subjective image enhancement in the radiographic diagnosis of caries.

This study aims to assess the influence of high-density material on the radiographic diagnosis of proximal caries in digital systems with automatic exposure compensation, and to evaluate the effect of subjective adjustment of brightness and contrast to undertake this diagnostic task. Twenty bitewing radiographs of forty posterior human teeth with non-cavitated carious lesions, confirmed by micro-CT, were obtained with two digital systems. A porcelain-fused-to-metal crown attached to a titanium implant was inserted into the exposed area, and all the radiographs were repeated. Five radiologists assessed the radiographs and diagnosed proximal carious lesions. Afterwards, the observers were asked to adjust image brightness and contrast, based on their subjective perception, and to reassess the images. Thirty percent of each experimental group was reassessed to test intraobserver reproducibility, totaling 208 images per observer. Intraobserver and interobserver agreements ranged from fair to substantial. Sensitivity, specificity, predictive values, and area under the ROC curve were calculated and compared for each radiographic system, using ANOVA (α = 0.05). Overall, presence of high-density material and adjustment of brightness and contrast did not significantly influence the radiographic diagnosis of proximal caries (p ≥ 0.05). Regarding Digora Optime, adjustment of brightness and contrast significantly increased (p < 0.05) the diagnostic accuracy of proximal carious lesions in the presence of high-density material. In conclusion, the presence of high-density material in the X-rayed region does not influence radiographic diagnosis of proximal caries. However, when it is present in the X-rayed area, subjective adjustment of brightness and contrast is recommended for use with the Digora Optime digital system.

Correlation of Visual and Radiographic Caries Diagnosis using the ICDAS in Permanent Molars of a Group of Egyptian Children

ICDAS (International Caries Detection and Assessment System) is an evidence-based detection and assessment system classifying stages of the caries process on the basis of histological extent and activity. The ICDAS measures the visual surface changes which corresponds to the potential histological depth of carious lesions. In addition, it proposes the ICDAS radiographic scoring system, which categorizes lesions according to the depth of caries demineralization into enamel and dentin represented by a radiolucency on the radiographs. In this study, the aim was to assess the relationship between clinical and radiographic caries diagnoses among 12 to 14-year-old Egyptians using the ICDAS scoring system which differentiates between cavitated and non-cavitated caries lesions.

Low reproducibility between oral radiologists and general dentists with regards to radiographic diagnosis of caries

Aim: Early clinical and radiological diagnosis of dental caries is one of the fundamental objectives of clinical dentistry because of the high frequency of the disease and severe complications if caries remains untreated, especially among the elderly and patients with immunodeficiency. Dental panoramic tomography (DPT) is a common radiographic method for evaluating dentition when indicated, especially in an adult population. The aim of this study was to assess the reproducibility of diagnosis between specialists in oral radiology and general dentists with regards to caries lesions based on DPTs of adults.Material and methods: One-hundred DPTs taken from adult patients (average age 35) and then analyzed and reported on by 42 general dentists were then analyzed independently by two specialists in oral radiology with respect to caries lesions in the premolar and molar areas using radiographic criteria established for caries diagnosis. The general dentists versus oral radiologists were not calibrated before. Level of agreement between specialists and general dentists was measured using Cohen’s kappa.Results: Comparison between observations of general dentists and specialists in oral radiology showed that 61% of the caries lesions on proximal surfaces of premolars and molars observed by specialists went unobserved by general dentists. Cohen’s kappa value for specialists was 0.85 (p < .001) and for each specialist and general dentists 0.48 (p < .001) and 0.44 (p < .001).Conclusions: The reproducibility between specialists in oral radiology and general dentists for detecting caries in DPTs was low.

Accuracy of extraoral bite-wing radiography in detecting proximal caries and crestal bone loss

BackgroundExtraoral bite-wing (EB) radiography is an imaging technology used in dentistry. The authors conducted an in vivo study comparing the accuracy of intraoral bitewing (IB) radiographs and EB radiographs for proximal caries and bone loss diagnosis. MethodsThe authors recruited 116 patients who received IB radiographs to receive EB radiographs. The 5 calibrated authors made a consensus radiographic diagnosis of proximal caries and crestal bone loss. For this study, they assumed IB radiographs as the criterion standard. Next, they obtained EB radiographs for the 116 patients and calculated sensitivity, specificity, and false-positive rates against each patient’s IB radiograph. ResultsThe patients’ EB radiographs revealed a significantly greater number of caries and crestal bone loss findings compared with their IB radiographs. The EB radiographs had a high to excellent sensitivity and moderate to low specificity of caries and crestal bone loss findings, respectively. Considering IB radiographs to be the criterion standard, the false-positive rate for EB radiographs was moderate for caries and high for bone loss diagnosis. ConclusionsThe EB radiographs, which generate fewer images of overlapping proximal surfaces, have the advantage of detecting more carious lesions and bone loss findings than the IB radiographs do, but with the disadvantage of more false-positive diagnoses. Further research is needed to evaluate if the false-positive findings represent true carious lesions and bone loss. Practical ImplicationsEB radiography is a promising technology, which has several advantages over traditional IB radiography. Clinicians should be aware of false-positive diagnosis of caries and bone loss with EB radiography.

Radiographic diagnosis of proximal caries-influence of experience and gender of the dental staff.

The aim of this study was to examine the influence of experience and gender on the radiographic detection of proximal caries lesions and on therapeutic decisions. A survey of 220 examiners (students and employees at three universities and dentists in the field) was taken using a standardized written questionnaire concerning radiographic diagnosis and therapy planning. An expert opinion of four dentists was determined as radiographic reference. A mixed effect logistic regression model was used for statistical evaluation and the odds ratio and p values were calculated (α=0.05). Examiners with experience had an almost four times greater chance of a correct assessment, if proximal caries lesion was present or not, than examiners with low experience (OR 3.7 (95% CI 2.4-5.8)). No gender-specific differences were discovered (OR women vs. men 0.9 (95% CI 0.6-1.4)). There was a relationship between the severity of the burnout effect on the x-ray and false positive caries diagnosis. Overall, 43% of respondents would plan invasive treatment in the enamel on a patient at low risk of caries and 78% on a high-risk patient. The results showed that the more experienced practitioners would be more likely to postpone restorative therapy on proximal caries until the lesion reached a later stage. The results of this study suggest that examiner's experience influences the radiographic diagnosis of proximal lesions. No gender-specific differences could be found. Examiner's professional experience is an important factor when radiography is included for detection and treatment planning of proximal lesions.

Correlation Of Clinical And Radiographic Diagnosis Of Carious Lesions In Posterior Teeth

ABSTRACT. Introduction: dental caries is a public health problem affecting a large percentage of the population. The carious process is highly variable and has periods of progression that alternate with periods of stability of the damaged tissue. There are different techniques to diagnose dental caries, including clinical and radiographic evaluation. Objective: the objective of this study was to establish correlation between the clinical and radiographic caries diagnosis suggested by ICCMS TM , in deciduous and permanent molars of a school population. Methods : descriptive study evaluating a sample for convenience of 1174 proximal and occlusal tooth surfaces of permanent and deciduous molars, taken from the database of 35 outpatients treated at the school of dentistry, who were clinically and radiographically evaluated for caries as recommended by the ICCMS TM based on bitewing x-rays. Results: the clinical and radiographic diagnosis was correlated in 1174 proximal and occlusal surfaces, with 0.41 Spearman's rank correlation coefficient (p < 0,05). The findings suggest that 95.6% of teeth diagnosed as healthy coincided with the clinical and radiographic results; in early mild stages, there was coincidence in only 8.16% and 6.4% respectively. Conclusions: there is low correlation between the clinical diagnosis of caries and the radiographic examination, in relation to ICCMS TM standards

The Role of Online Learning in Radiographic Diagnosis in Dental Education

The purpose of the pilot study was to investigate whether an interactive online module improved third-year dental students’ radiographic caries diagnosis abilities and conceptual understanding. Third year dental students were given online tutoring modules and assessed afterward to determine whether their diagnostic skills improved, whether they perceived and improvement in their diagnostic skills, and whether following the modules with interactive group discussions was a more effective teaching method. The choice to use the module was left to each individual. Thirty-one students completed an assessment consisting of three full-mouth series (FMX) radiographs of varying number and severity of carious lesions first individually and then in teams. Performance was evaluated quantitatively and qualitatively. A T-test analysis revealed that the students who accessed the module did not perform significantly better than students who did not access the module; however, a χ 2 -test showed that students who accessed the module correctly diagnosed yet over- and under-diagnosed more frequently. Survey responses showed that students believed the module helped clarify lecture topics. The online radiographic caries diagnosis module has introduced a promising and beneficial adjunctive resource for dental students.

Radiopacity of dental restorative materials

Radiopacity of dental materials enables clinician to radiographically diagnose secondary caries and marginal defects which are usually located on the proximal gingival margin. The aim of this study was to measure the radiopacity of 33 conventional resin composites, 16 flowable resin composites, and 7 glass ionomer cements and to compare the results with the radiopacity values declared by the manufacturers. From each restorative material, six 2-mm-thick disk-shaped specimens were fabricated and eight 2-mm-thick sections of teeth were made and used as reference. The material samples and tooth sections were digitally radiographed together with the aluminum stepwedge. Gray values were obtained from the radiographic images and radiopacity values were calculated and statistically analyzed. Post hoc Tukey's honestly significant difference test was used to calculate significant differences in radiopacity values between materials and reference dentin and enamel values. The radiopacity values of all 56 restorative materials were above the dentin reference radiopacity value; however, 4 out of 33 conventional composites and 3 out of 16 flowable resin composites had significantly lower radiopacity than enamel (p < 0.05). There were up to 1.53 mm eq Al differences between the measured and the manufacturers' declared radiopacity values of some materials. Majority of the materials exceed enamel radiopacity and would not hamper radiographic diagnosis of secondary caries. However, manufacturers' data are not always reliable. Materials with radiopacity lower than enamel might be misinterpreted as secondary enamel caries on radiographic images, especially when applied as initial increment on the proximal gingival margin.

In vitro comparison of intraoral films and four image plate systems in radiographic caries diagnosis

ABSTRACT In vitro comparison of intraoral films and four image plate systems in radiographic caries diagnosis Objectives: Detecting early caries lesion on a radiograph may be a difficult task. The aim of this study was to compare four image plate and two film-based systems by evaluating the accuracy of caries detection under standard conditions. Methods: Two hundred teeth were attached in groups of five onto plastic Lego®blocks. Radiographs were taken from each block under standard bitewing conditions with an X-ray device. Phosphor plates (Dentsply DenOptics®, Durr Vistascan II®, Soredex Digora FMX®, Soredex Digora Optime®) were exposed at 60 kV and 7 mA. The caries depths were analyzed by eleven observers and microscopic investigation was used to compare the histological findings. The caries depth was calculated as the difference between microscopic and radiological findings. Results: Data analysis showed a small impact of different sensors on the diagnostic accuracy. The largest differences between microscopic and radiographic caries ratings were found with DenOptix and Digora FMX. When it was calculated over all surfaces no statistical significance was found.

Influence of materials radiopacity in the radiographic diagnosis of secondary caries: evaluation in film and two digital systems

The aim of this study was to evaluate the influence of restorative materials on false-positive diagnoses of secondary caries using three imaging systems. Class II preparations were made on the occlusal and mesial or distal faces of extracted healthy third molar teeth. The teeth were divided into five groups and, with the exception of Group 5, they received a flow resin base. Groups 1, 2, 3 and 4 received a layer of Natural Flow (DFL, Rio de Janeiro, Brazil), Filtek Flow (3M-ESPE, St. Paul, MN), Tetric Flow (Ivoclar/Vivadent, Liechtenstein, Germany) and Protect Liner F (Kuraray, Okayama, Japan) resins, respectively, and were restored with Filtek Supreme resin (3M-ESPE). Group 5 was restored with Filtek Supreme resin. The images on film and on the Digora Optime® (Helsinki, Finland) and charge coupled device (CCD) IOX (IOX, Monninkylä, Finland) digital systems were evaluated by five examiners and the data were analysed using the Fisher's exact and Friedman tests at a 5% level of significance. Group 3 showed the highest rate of correct answers (restored tooth) and the lowest proportion of secondary caries diagnosis (P ≤ 0.05). Group 4 showed the highest rate of secondary caries diagnosis and the lowest proportion of correct answers (P ≤ 0.05). The systems for obtaining images presented were similar for each material. The restorative material was found to have an influence on the diagnosis of secondary caries lesions by imaging. The imaging system had no influence. Materials with greater radiopacity, higher than that of enamel, were favourable for a true-negative diagnosis.

Gold standard for the comparison of the diagnostic accuracy of panoramic images for approximal caries detection

Free AccessLetter to the editorGold standard for the comparison of the diagnostic accuracy of panoramic images for approximal caries detectionA WenzelA WenzelDepartment of Oral Radiology, School of Dentistry, Aarhus University, Denmark; E-mail: Search for more papers by this authorPublished Online:28 Jan 2014https://doi.org/10.1259/dmfr/18326926SectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail AboutDentomaxillofacial Radiology (2009) 38, 245. doi: 10.1259/dmfr/18326926The authors of the research article titled “A comparison of the diagnostic accuracy of bitewing, periapical, unfiltered and filtered digital panoramic images for approximal caries detection in posterior teeth” published in Dentomaxillofacial Radiology 2007; 37: 441–4421 claim that a particular emboss filter for panoramic images has a higher diagnostic value than original images for detection of caries lesions. The authors of this study use a “consensus of the three observers” as an expression for the true state of the disease (a caries lesion). In fact, no data are available for the true state of the disease in this study. It is therefore unfortunate that the data are treated by receiver operating characteristics (ROC) analysis (which demands that a solid gold standard is available) and that the term “diagnostic accuracy” is used.Three criteria should be fulfilled for a method to provide a worthy gold standard:it should be established by a method that is itself precise, i.e. reproducibleit should reflect the pathoanatomical appearance of the diseaseit should be established independently of the diagnostic method under evaluation.2The three-observer-consensus-truth does not fulfill any of these criteria.It has moreover been shown that not only will ROC areas become extremely large (around 0.9) when an observer is also the gold standard (logically, since the same mind that produces the test results produces the reference results against which the test is held), but also the mutual accuracy among the modalities tested is different when a solid gold standard and an observer-consensus-standard is applied. The results from a study with the latter design can therefore not be trusted, neither regarding the diagnostic accuracy of the modalities, nor the mutual performance among the modalities.3, 4 It only muddles our findings. References 1 Akarslan ZZ, Akdevelioglu M, Güngör K, Erten H. A comparison of the diagnostic accuracy of bitewing, periapical, unfiltered and filtered digital panoramic images for approximal caries detection in posterior teeth. Dentomaxillofac Radiol 2008;37:458–463. Link ISI, Google Scholar2 Wenzel A, Hintze H. The choice of gold standard for evaluating tests for caries diagnosis. Dentomaxillofac Radiol 1999;28:132–136. Crossref Medline ISI, Google Scholar3 Wenzel A, Hintze H. Comparison of microscopy and radiography as gold standards in radiographic caries diagnosis. Dentomaxillofac Radiol 1999;28:182–185. Link ISI, Google Scholar4 Hintze H, Wenzel A. Influence of the validation method on diagnostic accuracy for caries. A comparison of six digital and two conventional radiographic systems. Dentomaxillofac Radiol 2002;31:44–49. Link ISI, Google Scholar Previous article Next article FiguresReferencesRelatedDetailsCited byROLE OF ARTIFICIAL INTELLIGENCE APPLICATIONS IN DENTOMAXILLOFACIAL RADIOLOGY: PART 124 August 2022 | Selcuk Dental JournalRadiographic modalities for diagnosis of caries in a historical perspective: from film to machine-intelligence supported systemsAnn Wenzel4 March 2021 | Dentomaxillofacial Radiology, Vol. 50, No. 5Caries20 February 2013Reply to the above commentary on the Letter to the Editor entitled “Gold standard for the comparison of the diagnostic accuracy of panoramic images for approximal caries detection” published in Dentomaxillofacial Radiology (2009;38:245)A Wenzel29 May 2014 | Dentomaxillofacial Radiology, Vol. 38, No. 7 Volume 38, Issue 4May 2009Pages: 187-246 © The British Institute of Radiology History Published onlineJanuary 28,2014 Metrics Download PDF

Radiographic diagnosis of incipient proximal caries: an ex-vivo study

The aim of this ex vivo study was to compare visual clinical and radiographic examinations to the histological analysis for proximal caries diagnosis in extracted permanent molars and premolars. The relationship between clinical aspects and carious lesions was also evaluated. Eighty-eight proximal surfaces (44 freshly extracted teeth) were longitudinally sectioned with a 370-microm diamond disk, thinned with wet silicon carbide paper and observed with a stereomicroscope at x40 magnification. Sensitivity and specificity were 65.6% and 83.3% for clinical examination and 29.7% and 95.8% for radiographic examination, respectively. Kappa values ranged from 0.64 to 0.91. The white spots corresponded to lesions restricted to enamel, while the dark spots corresponded to lesions that reached the dentinoenamel junction. In most cases, cavitation corresponded to dentin lesions. It may be concluded that interproximal radiographic examination is not a reliable method for detection of incipient proximal carious lesions.

Risk Factors for a False Positive Test Outcome in Diagnosis of Caries in Approximal Surfaces: Impact of Radiographic Modality and Observer Characteristics

The aim of this study was to evaluate the impact of image modality and observer characteristics on radiographic caries diagnosis with particular emphasis on the false positive (FP) test outcome. Eighty human teeth were radiographed by eight digital modalities and film. Eight observers scored caries lesions in each approximal tooth surface. Their use of image enhancement and time spent in assessing an image was recorded. Microscopy served as validation for the presence/absence of a lesion. Of 160 approximal surfaces, 63% were sound and 37% had lesions. Multivariate logistic regression analysis was performed with the FP test outcome as the dependent variable and the radiographic modality and observer’s gender, experience, employment, image enhancement, and time use as the independent variables. The significant risk factors for an FP test outcome were: (1) gender: males scored fewer FP than females (OR 0.26, CI 0.18–0.36); (2) experience: observers with no experience with digital radiography had a six times higher risk for an FP (OR 6.09, CI 4.9–8.1); (3) radiographic modality: two of the digital systems had a significantly lower risk for an FP [a phosphor plate system (OR 0.55, CI 0.37–0.73) and a sensor-based system (OR 0.65, CI 0.46–0.93)] and one phosphor plate system had a higher risk (OR 1.57, CI 1.17–2.13) than film; (4) time use: more time was spent when scoring an FP (OR 1.05, CI 1.03–1.05) than for any other test outcome. Type of employment and the use of image enhancement had no significant impact on the risk for an FP diagnosis.

Comparison of radiographic and clinical diagnosis of approximal and occlusal dental caries in a young adult population

Comparison of radiographic and clinical diagnosis of approximal and occlusal dental caries in a young adult population

Comparison of radiographic and clinical diagnosis of approximal and occlusal dental caries in a young adult population

The aims of the study were: (1) to determine if bitewing radiographs provided additional diagnostic yield for occlusal and approximal dental caries in adults aged between 17 and 30 years of age when compared with a clinical examination only, (2) how this translated into the measurement of dental caries experience, and (3) to determine the influence of water fluoridation on the diagnosis of dental caries in occlusal and approximal surfaces by clinical examination alone and by radiographic examination. Between November 2002 and March 2003 a total of 879 subjects aged 17-30 years had a clinical examination using visual and tactile criteria. Subsequent to this examination, bitewing radiographs were taken and viewed separately and blind. Approximal and occlusal surfaces of molars and premolars were examined on the radiographs. Between 22.9-32.9% of approximal caries and 75.9-82.9% of occlusal caries was detected by clinical examination, while 93.1-97.1% of approximal caries and 33.1-42.6% of occlusal caries was detected by radiographic examination. In addition, while only 0.97% of clinically sound approximal surfaces and 0.83% of clinically sound occlusal surfaces were diagnosed with dentine caries on the radiographs, 67.1-77.1% of approximal caries was detected by radiographs alone, an additional diagnostic yield of 204-336%. The DS score increased 45-46% and the DMFS score increased 6-11% from the clinical examination with the addition of the radiographic information (P<0.001). The prevalence of approximal and occlusal caries was underestimated when clinical means only were employed. There was a significant increase in DS and DMFS scores from the clinical examination only when radiographic information was added across all age groups (P<0.001). This study confirms the value of bitewing radiographs in caries diagnosis.

A longitudinal study of occlusal caries among schoolchildren in Dar es Salaam, Tanzania

To describe the clinical caries status and the radiographic progression of occlusal caries lesions in permanent first and second molars among primary schoolchildren in Dar es Salaam over a 3-year period. Clinical and radiographic diagnosis of caries in first and second permanent molars in 223 children aged 8-16 years were carried out annually from 1994 to 1997. The drop-out rates from the baseline in 1994 to the follow-up examinations in 1995, 1996 and 1997 were 16.6%, 22.0% and 35.4%, respectively. Twenty-one percent of the dropouts were picked up during the study. Less that 5% of all occlusal surfaces that were sound at the beginning of the study developed new clinical caries lesions over the 3-year study period. The highest rate of new lesions was found in second molars. The mandibular second molars were most frequently affected by new caries lesions followed by the mandibular first molars. Progression of lesions was generally slow. After 1, 2 and 3 years, 30.0%, 47.9% and 52.8% of lesions in occlusal surfaces of first molars had progressed, compared to 47.9%, 71.3% and 100.0% of lesions in second molars. Dental caries prevalence was low. New occlusal lesions were more likely to appear in mandibular second molars. Carious lesions were progressing slowly, especially in the first molars. Fissure abrasion may play a role in minimizing the risk of developing new occlusal lesions as well as progression of existing lesions.