Inner Half Of Enamel Research Articles

Microleakage Assessment of Modified Resin Infiltration With Zinc Oxide (ZnO) and Magnesium Oxide (MgO) Nanoparticles on Artificial Enamel Caries Lesion: An In Vitro Study.

Background Incorporating nanoparticles into resin infiltrant (RI) can alter its physical properties, including microleakage. This study aimed to examine the microleakage properties of RI modified with 2.5% and 5% zinc oxide (ZnO) and magnesium oxide (MgO) nanoparticles on artificially induced carious lesions (ACLs) in bovine teeth. Materials and methods Modified RIs were applied to five sound and 30 ACLs on bovine incisors. They were divided into seven groups based on the procedure (Group 1: sound enamel (SE), Group 2: artificial caries lesion only (ACL), Group 3: RI, Group 4: RI+ 2.5% ZnO, Group 5: RI + 5% ZnO, Group 6: RI + 2.5% MgO, Group 7: RI + 5% MgO). The samples were subjected to 5000 thermal cycles and then exposed to methylene blue solution for 24 hours in an incubator. The teeth were sectioned and examined with a stereomicroscope to assess the depth of methylene blue penetration (MBP), quantifying microleakage according to the following scoring: 0 = no penetration, 1 = outer half of enamel, 2 = inner half of enamel, 3 = outer half of dentin, and 4 = inner half of dentin. An ANOVA test was conducted to assess the significance of differences among the groups. Post-hoc tests, including Tukey's HSD (honestly significant difference) test, were performed to identify specific group differences and determine which differences were statistically significant. Results SE samples (Group 1) showed minimal penetration, with 100% scoring 1, indicating high resistance to MBP. The ACL group had significant penetration, with 77.78% scoring 3 and 22.22% scoring 2. The RI group completely prevented MBP, with all samples scoring 0. Both RI+2.5% ZnO (Group 4) and RI+2.5% MgO (Group 6) were highly effective, with 88.89% scoring 0 and 11.11% scoring 1. RI+5% ZnO (Group 5) and RI+5% MgO (Group 7) also prevented MBP but had slightly higher minimal penetration, with 77.78% scoring 0 and 22.22% scoring 1. Significant differences were observed between the ACL group and all other groups, underscoring the effectiveness of RI treatments. No significant differences were found between RI+ZnO and RI+MgO at both concentrations, indicating similar effectiveness. Conclusions The study demonstrated that RI modified with 2.5% and 5% ZnO and MgO nanoparticles effectively reduced microleakage in ACLs on bovine teeth compared to untreated lesions. These modifications significantly inhibited MBP, particularly in enamel and dentin, indicating their potential to enhance the durability and effectiveness in clinical applications. This research emphasizes the promising role of nanoparticle-modified RI in minimizing microleakage and optimizing treatment outcomes. Further research is needed to confirm these findings and refine protocols.

Determining the Ability of Senior Dental Students to Detect Interproximal Caries Using Different Radiographic Techniques.

Objective: To evaluate the diagnostic capability of 5th-year students using digital imaging, conventional bitewing (BW) radiographs, and printed film on paper to detect interproximal caries lesions. Methods: A cross-sectional study was conducted with senior dental students. Three different radiographs: digital, BW, and printed films on paper were used; thus, nine radiographs, each with a 2-min viewing time, were considered by students along with a questionnaire. A control group of specialists from Prosthodontics and Radiology had finalized the answers prior to conducting the study. The appropriate responses were divided into five categories: R0: Intact surface, R1: Radiolucency in the outer half of enamel, R2: Radiolucency in the inner half of enamel, R3: Radiolucency in the outer half of dentin, and R4: Radiolucency in the inner half of dentin. Students' responses were analyzed using a one-way analysis of variance (ANOVA) test and a t-test. Results: Ethics for the study was obtained from the institutional committee (Reg No: BM19/9/8). When compared with the control group using ANOVA testing, the results showed good detection accuracy with a success rate of ~64 accuracy. There was a significant difference in the outcomes when detecting the presence of the caries lesion between the three diagnostic techniques (p > 0.001). In detecting the size of the carious lesion, the students' ability was recorded as poor. The highest average for detecting the presence of the carious lesion was correspondent to the printed film on paper method. Conclusions: Senior dental students have shown good accuracy in detecting the presence but not the size of interproximal caries on all radiographs viewed. Clinical Significance: Teachings and availability of diverse radiological diagnostic techniques ensured a reasonable level of understanding and use of the diagnostic caries risk assessment methodologies as required in restorative treatment planning.

Impact of angle on photothermal radiometry and modulated luminescence (PTR/LUM) value

ObjectiveTo evaluate the impact of scanning angles to detect/quantify non-cavitated caries by photothermal-radiometry and modulated-luminescence (PTR/LUM, Canary System) and to evaluate the association of PTR/LUM value with lesion depth (LD), including sound tissue thickness under the lesion (ST). MethodsThirty human extracted premolars were selected based on micro-computed tomography [μ-CT: sound (n=12), lesions into outer-half of enamel (n=6), lesions into inner-half of enamel (n=6), lesions into outer one-third of dentine (n=6)]. Each tooth sample was scanned 90° directly contacted to the center of non-cavitated lesion or sound smooth surface, and tilted 10° and 20° in four directions: buccal/lingual/occlusal/cervical. The procedure was repeated 48 h later. Lesion depth and ST [ST=5000 µm (maximum PTR/LUM scanning depth)-LD] were measured at the same scanning direction on μ-CT images. Sensitivity, specificity, area under the Receiver Operating Characteristic curve (AUC), and intraclass correlation coefficients (ICC) for different scanning angles were calculated. Sensitivity was further evaluated based on lesion extensions. Relationships between PTR/LUM value and lesion depth, and between PTR/LUM value and LD/ST-Ratio were evaluated. ResultsPTR/LUM value showed significant differences among scanning angles. Overall sensitivity (78%–89%), specificity (66%–87%), AUC (0.86–0.92) and ICC (0.89–0.99), sensitivity based on lesion extensions presented no significant differences among angles. PTR/LUM value showed moderate correlations (0.56–0.74) with deepest lesion depth and LD/ST-Ratios. ConclusionThe scanning angle within 20° increments might impact PTR/LUM value statistically; however, it did not affect PTR/LUM detection performance. PTR/LUM values were positively correlated with non-cavitated lesion depth, and not affected by sound tissue thickness under the lesion. Clinical significance: Clinically, it is challenging to measure/scan at the same location and same angle longitudinally, however, it is important to standardize these parameters. Scanning within 20° deviation from perpendicular did not affect detection performance of PTR/LUM, and PTR/LUM value showed positive moderate correlation with caries depth.

Occlusal caries detection on 3D models obtained with an intraoral scanner. A validation study

ObjectivesTo evaluate the diagnostic performance of visual caries assessment on 3D dental models obtained using an intraoral scanner and to compare it with the performance of the clinical visual inspection. MethodsFifty-three permanent posterior teeth scheduled for extraction were randomly selected and included in this study. One to three independent examination sites on the occlusal surface of each tooth were clinically inspected using International Caries Detection and Assessment System (ICDAS) criteria. Afterwards, the examined teeth were scanned intraorally with a 3D intraoral scanner (TRIOS 4, 3Shape TRIOS A/S, Copenhagen, Denmark) using white and blue-violet light (415 nm wavelength) to capture the colour and fluorescence signal from the tissues. Six months after the clinical examination, the same examiner conducted the on-screen assessment of the obtained 3D digital dental models at the selected examination sites using modified ICDAS criteria. Both tooth colour and fluorescence texture with high resolution were assessed. Lastly, an independent examiner conducted the histological examination of all teeth after extraction. Using histology as the reference test, Sensitivity (SE), Specificity (SP), Accuracy (ACC), area under the Receiver Operating Characteristic (ROC) curve, and Spearman's correlation coefficient were calculated for the clinical and on-screen ICDAS assessments. ResultsThe ACC values of the evaluated methods varied between 0.59-0.79 for initial caries lesions and 0.77-0.99 for moderate-extensive caries lesions. Apart from SE values corresponding to caries in the inner half of enamel, no significant difference was observed between clinical visual inspection and on-screen assessment. In addition, no difference was found in the assessment of 3D models with tooth colour alone or supplemented with fluorescence for all the evaluated diagnostic measures. ConclusionsOn-screen visual assessment of 3D digital dental models with tooth colour or fluorescence showed a similar diagnostic performance to the clinical visual inspection when detecting and classifying occlusal caries lesions on permanent teeth. Clinical significance3D intraoral scanning can aid the detection and classification of occlusal caries as part of patient screening and can potentially be used in remote caries assessment for clinical and research purposes.

Proximal caries infiltration – Pragmatic RCT with 4 years of follow-up

ObjectivesEfficacy of proximal caries infiltration to arrest lesion progression has been shown in university settings, but only once in a practice-based pragmatic design with a follow-up of 18 months. The aim of this randomized split-mouth placebo-controlled study was to follow-up this cohort for 3 years and those with high caries risk for 4 years. MethodsOriginally, in 87 children and young adults pairs of 238 proximal caries lesions, radiographically extending into inner half of enamel (E2) or outer third of dentin (D1), were randomly allocated to two groups: infiltration (Icon; DMG) or mock (control) treatment by five dentists in four private practices. All subjects received risk-related instructions for diet, flossing and fluoridation. The primary outcome was radiographic lesion progression (pairwise comparison) evaluated by two evaluators independently being blinded to treatment allocation. ResultsAfter 36 months [mean (SD): 1152 (166) days] 165 lesion pairs in 64 patients as well as after 48 months [mean (SD): 1496 (121) days] 71 lesion pairs in 20 high caries risk patients could be re-evaluated clinically as well as radiographically using individualized bitewing holders as at baseline. No adverse events could be observed. After 36 months, progression was recorded in 23/165 test (14%) and 64/165 control lesions (39%) [McNemar/Obuchowski test; p<0.001; relative risk reduction (CI95%): 64 (45–77%)]. After 48 months lesion progression was recorded in 13/71 test (18%) and 34/71 control lesions (48%) [p = 0.003; relative risk reduction (CI95%): 62 (34–78%)] of high caries risk patients. ConclusionsIt can be concluded that also in a practice-setting proximal caries infiltration is more efficacious in reducing lesion progression compared with individualized non-invasive measures alone over a period of four years.

Detection and analyzing plane of non-cavitated approximal caries by cross-polarized optical coherence tomography (CP-OCT)

ObjectiveThe objective was to assess the detection ability and the effect of analyzing plane of CP-OCT for non-cavitated approximal caries. MethodsThirty human extracted premolars were selected based on micro-computed tomography [μ-CT: μ- CT = 0: sound (n = 12), μ-CT = 1/2: caries into outer-/inner-half of enamel (n = 6 each), μ-CT = 3: caries into outer one-third of dentine (n = 6)]. Teeth were mounted in a custommade device to simulate approximal contact, and scanned from the marginal ridge above the contact area. CP-OCT images were analyzed by deepest caries extension from horizontal and coronal planes, and repeated 48-hrs later. Sensitivity, specificity,percent correct, area under the ROC curve (Az), intra-examiner repeatability and correlation with μ-CT were determined. ResultsSensitivity/specificity/Az for Horizontalplane, Coronal-plane, and Deepest from both planes were 94percent/58percent/0.76,81percent/100percent/0.90, and 94 %/58 %/0.82. Coronal-plane had significantly higher specificity than Horizontal-plane and Deepest (p = 0.004) but Horizontal-plane and Deepest were not different (p = 1.00). Horizontal-plane had significantly lower Az than Deepest (p = 0.048), but Coronal-plane was not different than Horizontal-plane (p = 0.07) or Deepest (p = 0.20). Correlation coefficients were Horizontal-plane (0.53, p < 0.001), Coronal-plane (0.84, p < 0.001), and Deepest (0.66, p < 0.001). ConclusionWithin the limitations of this study, CP-OCT could be used to detect non-cavitated approximal caries. Analysis using the Coronal-plane is superior to the Horizontal-plane. Clinical Significance: It is challenging to detect non-cavitated approximal caries clinically due to the adjacent tooth. CP-OCT is a nondestructive, no ionized-radiation caries detection technique. CP-OCT seems suitable to detect non-cavitated approximal caries and observing the Coronal-plane appears better than Horizontal-plane.

Temporary Tooth Separation to Improve Assessment of Approximal Caries Lesions: A School-Based Study.

Radiographic lesion depth should not be used as the single determinant of the restorative threshold for clinically inaccessible approximal caries lesions. Temporary tooth separation is a feasible and effective diagnostic aid for assessment and appropriate management of approximal lesions. In the era of tooth-preserving dentistry, the decision to restore approximal caries lesions must be based on the accurate assessment of tooth cavitation, as the accumulation of oral biofilms in these areas encourages lesion progression. However, lesions radiographically into dentin remain the main threshold criterion for restoring approximal lesions even though most of these lesions may not be cavitated. A school-based clinical protocol for temporary tooth separation (TTS) was developed to improve visual-tactile assessment and management of clinically inaccessible approximal lesions. TTS data retrieved from electronic health records were used to correlate radiographic lesion depth and surface cavitation status with lesion location and the patient's caries risk and to evaluate the effectiveness of TTS as a diagnostic aid for approximal lesions. Of the 206 lesions assessed, 66.5% (n=137) were located in the maxillary arch, 56.6% (n=116) in distal surfaces, 61.3% (n=114) in premolars, and 21.5% (n=40) in molars. After tooth separation, 79.6% (n=164) of the lesions were diagnosed as noncavitated, including 90% (n=66) of the lesions radiographically at the inner half of enamel (E2) and 66% (n=49) of those at the outer-third of dentin (D1). Logistic regression analysis using E2 and D1 lesions showed no significant association between lesion depth or cavitation status with lesion location and caries risk. TTS is a feasible and effective diagnostic aid for the assessment and appropriate management of approximal caries lesions. There is a need to reevaluate the use of radiographic lesion depth as the single determinant of the restorative threshold for clinically inaccessible approximal lesions.

Seven-year-efficacy of proximal caries infiltration – Randomized clinical trial

ObjectivesWe report efficacy of resin infiltration to arrest progression of caries lesions as compared with non-invasive measures and oral hygiene education alone after a mean observation time of seven years. Materials and methodsThis randomized split-mouth placebo-controlled clinical trial included 22 young adults having 29 pairs of interproximal non-cavitated caries lesions with radiographic extensions into inner half of enamel (E2) or outer third of dentin (D1). Lesion pairs were randomly allocated to two treatment groups: infiltration (Icon, pre-product; DMG) or mock (control) treatment. All subjects received risk-related instructions for diet, flossing and fluoridation. The primary outcome was radiographic (digital subtraction radiography) lesion progression after seven years. Secondly, Kaplan-Meier-analyses were applied to analyze time-to-failure additionally including patients followed up for less than 54 months as well. ResultsTwo lesion pairs were excluded due to invasive treatment decision by another dentist, five lesion pairs were lost to follow-up prior to 54 months but included in the survival analysis. No unwanted effects could be observed. For the primary outcome in 17 patients followed up in mean for 84 months 2/22 infiltrated lesions (9 %) compared with 10/22 control lesions (45 %) progressed (p = 0.018). The relative risk reduction for test in relation to control was 80 % (CI 95 % = 19–95 %). For the survival analysis within a mean (SD) observation time of 73 (25) months mean failure rates of 1.3 % and 7.8 % could be observed for test and controls, respectively. Hazard risk (95 % CI) for caries progression was 6.6 (2–22) for the control compared with the test lesions (p = 0.002). ConclusionsWe conclude that resin infiltration of proximal caries lesions extending radiographically around the enamel dentin junction is efficacious to reduce lesion progression after a mean observation time of seven years. Clinical significanceThis randomized clinical trial proves that caries infiltration is highly efficacious compared with non-invasive measures and oral hygiene education alone after a considerably longer observation time of 7 years than studied so far before.

Detection ability and direction effect of photothermal-radiometry and modulated-luminescence for non-cavitated approximal caries

ObjectiveThe objective was to evaluate the ability of photothermal-radiometry and modulated-luminescence (PTR/LUM) to detect non-cavitated approximal caries lesions, including the effect of scanning direction. MethodsThirty human extracted premolars were selected based on micro-computed tomography [μ-CT: μ-CT = 0: sound (n = 12), μ-CT = 1: lesions into outer-half of enamel (n = 6), μ-CT = 2: lesions into inner-half of enamel (n = 6), and μ-CT = 3: lesions into outer one-third of dentine (n = 6)]. Teeth were mounted in a custom-made device to simulate approximal contact. Each tooth was scanned from three directions: buccal, lingual, and occlusal, then repeated 48 h later. Statistical analyses were performed by bootstrap analyses using average and maximum values across all directions. Sensitivity, specificity, area under ROC-curve (AUC), intraclass correlation coefficient (ICC) and correlation with μ-CT were calculated. Sensitivity was further evaluated based on lesion extension. ResultsUsing the manufacturer-suggested lesion cut-off, overall sensitivity ranged from 3%–61%, where the maximum value of all measurements (All-max) showed higher sensitivity (61 %) than other measurements except the buccal direction, which was also higher than the lingual and occlusal directions. As μ-CT score increased from μ-CT = 1–3, the sensitivity of All-max also increased from 50 % to 74 %. Specificity was 100 % regardless of direction, and AUC ranged from 0.65 to 0.88. All-max had the highest ICC (0.74). PTR/LUM values showed weak to moderate correlations with μ-CT. ConclusionWithin the limitations of this in vitro study, PTR/LUM non-cavitated approximal caries lesion detection achieved best individual results from the buccal direction, while using the maximum value from all directions might improve performance. Clinical significanceNon-cavitated approximal caries detection is a challenging procedure. PTR/LUM is a nondestructive, no ionized-radiation caries detection method that can scan from buccal, lingual, and occlusal directions of an approximal surface. PTR/LUM seems suitable to detect deeper non-cavitated approximal caries. The maximum PTR/LUM value from three directions may be optimal.

Detection of Approximal Caries Lesions in Adults: A Cross-sectional Study.

Detection and management of posterior approximal caries lesions are still problematic. Inspection of approximal surfaces is challenging, and bitewing radiographs are used when direct vision is not possible. Unfortunately, there is no definite radiographic appearance to identify lesion cavitation with absolute certainty. Many lesions detected radiographically within the outer half of dentin are not cavitated, often resulting in unnecessary restorative treatment. Our study compared radiographic depth of approximal caries lesions with presence of cavitation in adults using visual inspection following temporary tooth separation (TTS). We conducted this observational descriptive cross-sectional study at two dental schools in two cities in Chile. Clinicians were unaware of radiographic depths of lesions and examined 147 participants (57.3% female and 42.7% male) following TTS. Using the common classification system that consists of E0 (no lesion), E1 (lesion within the outer half of enamel), E2 (lesion within the inner half of enamel), D1 (lesion within the outer third of dentin), D2 (lesion within the middle third of dentin), and D3 (lesion within the inner third of dentin), a trained dentist evaluated all the processed films. Cavitation was detected in only three sites (0.22%) within the E0 category, seven sites (3.41%) in E1, five sites (14.8%) in E2, four sites (14.8%) in D1, six sites (50%) in D2, and eight sites (61.5%) in D3. Considering that restorative treatment should be indicated strictly for cavitated lesions, our findings support indication for restorative treatment for D3 lesions and the rationale for TTS for D1-D2 caries lesions to allow direct visual inspection to determine whether there is surface cavitation.

Randomized controlled clinical trial of resin infiltration in primary molars: 2 years follow-up

ObjectiveThe aim of this split-mouth, randomized, controlled clinical trial was to evaluate the efficacy of resin infiltration in controlling the progression of non-cavitated proximal lesions in primary molars after two-years follow-up. MethodsFifty healthy children presenting at least two primary molars with proximal lesion detected radiographically (in the inner half of enamel or the outer third of dentin) were included in the study. The proximal lesions were randomly allocated into resin infltration + flossing (test group) or flossing (control group). All patients received oral hygiene instructions for daily brushing with fluoride toothpaste (1100 ppmF) and flossing. The proportion of caries progression was compared using the McNemar test. The main outcome after 2-years, caries progression in the radiography was assessed by pair-wise reading by an independent examiner who was blind regarding the treatment. ResultsThe sample comprised 28 (56%) girls and 22 (44%) boys with a defs of 7,3 (SD = 6,5), mainly of moderate (46%) to high (48%) caries risk. Results after one year were published previously. After 2-years, 29 (58%) patients were assessed. Caries progression was observed in 24.1% (7/29) of the test lesions, compared with 55.2% (16/29) of the control lesions (p = 0.012). The therapeutic effect was 31.1% and the relative risk reduction (RRR) was 56.3%. Eigth lesions from the control group and two lesions from the test group progressed to the inner third of dentin and were restored. ConclusionsIn conclusion, resin infiltration was more efficacious in controlling proximal caries lesions in primary molars than non-invasive approach alone. Clinical Significance: The results indicate that resin infiltration was an efficacious method in controlling proximal caries lesions in primary molars after 2 years, even in patients with high caries risk, reaffirming the results of 1-year follow-up.

Dentists' perspectives on caries-related treatment decisions.

To assess the impact of patient risk status on Colombian dentists' caries related treatment decisions for early to intermediate caries lesions (ICDAS code 2 to 4). A web-based questionnaire assessed dentists' views on the management of early/intermediate lesions. The questionnaire included questions on demographic characteristics, five clinical scenarios with randomised levels of caries risk, and two questions on different clinical and radiographic sets of images with different thresholds of caries. Questionnaires were completed by 439 dentists. For the two scenarios describing occlusal lesions ICDAS code 2, dentists chose to provide a preventive option in 63% and 60% of the cases. For the approximal lesion ICDAS code 2, 81% of the dentists chose to restore. The main findings of the binary logistic regression analysis for the clinical scenarios suggest that for the ICDAS code 2 occlusal lesions, the odds of a high caries risk patient having restorations is higher than for a low caries risk patient. For the questions describing different clinical thresholds of caries, most dentists would restore at ICDAS code 2 (55%) and for the question showing different radiographic thresholds images, 65% of dentists would intervene operatively at the inner half of enamel. No significant differences with respect to risk were found for these questions with the logistic regression. The results of this study indicate that Colombian dentists have not yet fully adopted non-invasive treatment for early caries lesions.

Current Cariology Education in Dental Schools in Spanish–Speaking Latin American Countries

This study sought to provide an overview of current cariology education in Spanish-speaking Latin American dental schools. Data collection was via an eighteen-item survey with questions about curriculum, methods of diagnosis and treatment, and instructors' perceptions about cariology teaching. The response rate was 62.1 percent (n=54), and distribution of participating schools by country was as follows: Bolivia (four), Chile (four), Colombia (twenty-four), Costa Rica (one), Cuba (one), Dominican Republic (two), El Salvador (two), Mexico (six), Panama (two), Peru (four), Puerto Rico (one), Uruguay (two), and Venezuela (one). Forty percent of the responding schools considered cariology the key axis of a course, with a cariology department in 16.7 percent. All schools reported teaching cariology, but with varying hours and at varying times in the curriculum, and 77.8 percent reported having preclinical practices. The majority reported teaching most main teaching topics, except for behavioral sciences, microbiology, saliva and systemic diseases, caries-risk factors, root caries, erosion, and early caries management strategies. The most frequently taught caries detection methods were visual-tactile (96.3 percent), radiographic (92.6 percent), and the International Caries Detection and Assessment System (ICDAS) (61.1 percent). Respondents said their schools' clinics make an operative treatment decision when radiolucency is in the inner half of enamel (42.3 percent) for radiographic criteria and when the lesion is visually non-cavitated (5.8 percent). All respondents reported that their schools teach preventive strategies, but only 43.4 percent said they tie it to risk assessment and 40.7 percent said they implement nonsurgical management regularly.

A Pilot Study of a Modified Radiographic Technique for Detecting Early Proximal Cavities

Diagnosing the necessity of cavity preparation in demineralized proximal areas has been considered as a challenge in restorative treatment planning. The purpose of this study was to investigate the clinical performance of a modified radiographic technique for the detection of proximal cavities. The sample consisted of 44 proximal surfaces in 38 dental students. The patients had radiolucent proximal lesions restricted to the inner half of enamel or the outer third of dentine in bitewing radiographs, and there was doubt regarding the presence or absence of cavities in the approximal areas. The suspected surfaces were then examined by secondary bitewing radiographs which were taken after pressing radiopaque material into the proximal areas. Finally, orthodontic elastic separators were placed in the contact areas to provide enough space for direct visual and tactile examination, thus detecting any proximal cavity (reference standard). The sensitivity, specificity and accuracy of the modified bitewing radiography were calculated against the reference standard. Overall, 7 surfaces presented caries cavities according to the reference standard. All proximal radiolucencies observed in the inner half of enamel and 46% of those extended to the outer third of dentine were not cavitated when evaluated by direct visual and tactile examination. The sensitivity, specificity and accuracy of bitewing radiography with opaque material for detecting proximal cavities (n = 7) were 86, 100 and 98%, respectively. The tested radiographic technique displayed good validity in this pilot study for detecting proximal cavities in posterior teeth and should be further investigated.

Randomized Controlled Clinical Trial on Proximal Caries Infiltration: Three-Year Follow-Up

We report the 3-year efficacy of resin infiltration (Icon, pre-product; DMG, Hamburg) to arrest progression of proximal non-cavitated caries lesions as compared with placebo treatment. In 22 young adults, 29 lesion pairs with radiographic extensions into the inner half of enamel up to the outer third of dentin were included (split-mouth design). All subjects received risk-related instructions for diet, flossing and fluoridation. No unwanted effects could be observed. Radiographically 1/26 test lesions (4%) and 11/26 control lesions (42%) had progressed (p = 0.002, McNemar). After 3-year follow-up, infiltration of proximal caries lesions can be said to be efficacious to reduce lesion progression.

Resin Infiltration of Caries Lesions

Resin infiltration is an innovative approach to arrest progression of caries lesions. The aim of this randomized split-mouth placebo-controlled clinical trial was to assess whether resin infiltration of proximal lesions is more effective than non-operative measures alone with respect to the inhibition of caries progression. In 22 young adults, 29 pairs of interproximal lesions with radiological extension into the inner half of enamel or the outer third of dentin were randomly allocated to two treatment groups. In the test group, lesions were infiltrated (Icon, pre-product; DMG). A placebo treatment was performed in the control group. All participants received instructions for diet, flossing, and fluoridation. The primary outcome after 18 months was radiographic lesion progression (assessed by digital subtraction radiography). No unwanted effects could be observed. In the effect group, 2/27 lesions (7%) and in the control group 10/27 lesions (37%) showed progression (p = 0.021; McNemar). Infiltration of interproximal caries lesions is efficacious in reducing lesion progression.

Efficacy of Sealing Proximal Early Active Lesions: An 18-Month Clinical Study Evaluated by Conventional and Subtraction Radiography

This study assessed the efficacy of sealing proximal lesions on adult patients using a split-mouth design. Eighty-two 15- to 39-year-olds from the Dental Faculties in Copenhagen and Bogotá participated, each having 2 or more proximal lesions in the following radiographic stages: (1) lesion restricted to the outer half of enamel; (2) lesion from the inner half of enamel including the enamel dentine junction, and (3) lesion restricted to the outer third of dentine. Standardized geometrically aligned baseline and follow-up radiographs were obtained. One randomly selected lesion (test) in each patient was sealed with 1 of 2 resins. The patients were instructed to floss all the proximal lesions 3 times per week. The baseline to 18 months difference in caries lesion progression status was assessed using 3 methods: (1) radiographs were independently assessed visually; (2) radiographs were read in pairs, and (3) using subtraction radiography of digitized images. A total of 72 subjects finished the study (12.2% dropout). The compliance concerning flossing was poor (15%). For the repeated examinations kappa was 0.84 for the visual examination, 0.44 for the paired readings and 0.84 for the subtraction examination. Two test lesions and 1 control lesion were restored. For the independent radiograph assessment method 10 and 26% progressed in the test and control group, respectively (p > 0.05); with the paired radiograph method the corresponding data were 22% in the test and 47% in the control groups (p < 0.01). By subtraction radiography 44% of the test group and 84% of the control were judged to have progressed (p < 0.001). The sealing technique was superior to instructing patients to floss, and subtraction radiography appeared to be the most sensitive method for assessing lesion progression.

Evaluation of cavitations in proximal caries lesions at various magnification levels in vitro

The aim of this study was to evaluate the cavitation rate of proximal caries using different magnification aids in vitro. Radiographs of 285 extracted teeth were taken and the proximal surfaces were graded to the criteria R0 (no radiolucency), R1 (radiolucency confined to the outer half of enamel), R2 (inner half of enamel) and R3 (outer half of dentin). Subsequently, the proximal surfaces were checked for the presence of cavitations with the naked eye (NE), and by using 4.3 x magnification eyeglasses (ME), a stereo microscope (SM, 10x), or a scanning electron microscope (SEM, up to 2000 x magnification). In surfaces with R3 caries, cavitations were visible in 56 of 59 cases with the naked eye. When using SEM, all surfaces revealed cavitations (100%). Regarding the surfaces with R2 lesion, 36 of 46 cases showed cavitations (NE); the corresponding values were 39/46 (ME), 41/46 (SM), and 46/46 (SEM); in the latter, in most cases deep defects could be observed. With regard to R1 lesions, 36/60 (NE), 43/60 (ME), 45/60 (SM), and 58/60 (SEM) cases revealed cavitations. A breakdown of radiographically sound surfaces (R0) was present in some 10% of the examined surfaces (24/261, NE; 33/261, SEM). Cavitations (defined as breakdown of the surface) are present in significantly more cases than previously reported. This might be an explanation why even small radiolucencies tend to progress, albeit slowly. Thus, close follow-ups should strongly be recommended when considering a preventive treatment regimen with small radiolucencies.

Detection of Approximal Caries with a New Laser Fluorescence Device

The laser device DIAGNOdent developed for the detection of occlusal caries has limited value on approximal surfaces. The aim of this study was to develop and to test a new laser fluorescence (LF) device for the detection of approximal caries. Light with a wavelength of 655 nm was transported to the approximal surface using two different sapphire fibre tips. Seventy-five teeth were selected from a pool of extracted permanent human molars, frozen at –20°C until use. Before being measured, they were defrosted, cleaned and calculus was removed with a scaler. The molars were set in blocks simulating the contact area of adults. Bitewing radiographs were obtained using Kodak Insight films. After two independent assessments with the new LF device, the teeth were histologically prepared, and assessed for caries extension. Using the laser, specificity values for D₁threshold (outer half of enamel), D₂threshold (inner half of enamel), D₃threshold (dentine) ranged between 0.81 and 0.93, sensitivity between 0.84 and 0.92 with no difference between the two tips. Bitewing radiography showed an inferior performance compared to LF (p < 0.05). Intraex aminer reproducibility was high (kappa >0.74). The new LF system might be a useful additional tool in detecting approximal caries. Because of its good reproducibility, it could be used to monitor caries regression or progression on approximal surfaces.

An in vivo Comparison of Radiographic and Directly Assessed Clinical Caries Status of Posterior Approximal Surfaces in Primary and Permanent Teeth

At general dental practices in Scotland 211 children between the ages of 5 and 15 years were examined by 1 observer. A comparison of the status of 1,468 permanent and 756 primary posterior approximal surfaces was made on the basis of their appearance on posterior bite-wing radiographs and the findings of a direct in vivo visual examination, made after temporary tooth separation had been achieved over 1 week using elastomeric separation. For permanent tooth surfaces, 0% of radiolucencies in the outer half of enamel, 10.5% in the inner half of enamel, 40.9% extending to the outer half of dentine, and 100% extending to the inner half of the dentine were found clinically to be cavitated. The analogous results for primary teeth were that 2.0, 2.9, 28.3, and 95.5%, respectively, of radiolucencies appeared to be cavitated. Although further research with larger numbers of permanent teeth is indicated, these results may contribute to a re-evaluation of the optimal threshold for restorative intervention at approximal sites. Greater numbers of approximal radiolucencies and carious lesions (p less than 0.001) were found in those surfaces which initially had a normal anatomical contact when compared to those which did not.