Treatment success of carious primary molars with marginal breakdown: comparison of three treatment approaches in a real-world clinical setting (using decision tree analysis).

OBJECTIVES: Treatment of carious primary molars is always indicated, especially on young children; however, there are no clear guidelines that precisely explain the best treatment approach for Class II carious molars with marginal breakdown (International Caries Detection and Assessment System [ICDAS] 5). The objective of this prospective observational clinical study was to assess the efficacy of three restorative techniques in treating ICDAS 5 Class II lesions in primary molars: compomer fillings (CF), preformed metal crowns (PMC), and pulpotomy and conventional preformed metal crowns (PMC+P). The secondary goal was to evaluate the impact of some cofactors on the course of treatment. METHOD AND MATERIALS: Overall, 92 children (female, n = 50, 54.3%; male, n = 42, 45.7%) aged 2 to 9 years old (mean age = 5.9 ± 1.9 years) with 166 treated teeth were included. The average number of decayed, missing, or filled teeth (d3mft) of the whole sample was 8.0 ± 3.4. The distribution of the sample according to type of treatment was CF = 53 (31.9%), PMC = 64 (38.6%), and PMC+P = 49 (29.5%). Paired t test, nonparametric Friedman ANOVA test, and decision tree analysis were used as the basis for the statistics. RESULTS: After 12 months, data from 75.8% (72/95) treated patients, corresponding to 62.0% (103/166) of the treated teeth (CF = 42/53, 79.2%; PMC = 38/64, 59.4%; PMC+P = 23/49, 46.9%) were available for analysis. The mean patients age was 6.8 ± 1.8 years; 32 (47.1%) boys and 36 (52.9%) girls. The mean d3mft of the remaining sample was 7.8 ± 3.35. PMC and PMC+P arms showed the highest success rates (> 91%) as compared to the CF arm, which showed the lowest success rates (61.9%), with 9/42 teeth of the CF group (21.4%) presenting with minor failures, and 7/42 teeth (16.7%) with major failures (P < .0001). CONCLUSION: According to the decision tree analysis, PMC and PMC+P had a success rate of 99%, whereas CF had a success rate of only 69%. Some cofactors (treatment decision, Approximal Plaque Index, and tooth number) had a higher impact on the decision tree analysis than others (age, dmfs, and dmft values), especially when the treatment selection was CF. In future studies it is necessary to examine the impact of other cofactors on the outcomes of conventional fillings using a larger sample size.

Role of Marginal Ridge Shape and Contact Extent in Proximal Caries Between Primary Molars.

OBJECTIVES: To determine different combinations of marginal ridge shape (MRS) and contact extents in nature of the contact between primary molars and its correlation with the presence of carious lesions on radiographic examination of approximal surfaces. STUDY DESIGN: Retrospective study of 347 clinical records, including photographs and bitewing radiographs, were assessed for intact MRS and caries extent. The carious lesions were scored (0-5, Mejàre scoring system) radiographically and correlated to the intact MRS on clinical photographs, and strength of associations quantified using logistic regression analysis and chi-square tests. RESULTS: Primary molars, 848(contact extent), and 757(MRS) were analyzed. Combination of straight-convex(35.4%) MRS was more common (p<0.001). None of the approximal surfaces were caries-free for straight and straight MRS with 36.4% of both approximal surfaces exhibiting caries in enamel, and 38.2% of one approximal surface exhibiting caries in dentin. Approximately 90% of the primary molars with substantial contacts exhibited carious lesions in the enamel and 80% with light contacts exhibited carious lesions in the dentin (p<0.001). CONCLUSION: Six different combinations of intact MRS were identified. Combination of concave-convex shapes exhibited caries extending into dentin. Substantial and/or light contacts between primary molars showed higher caries experience in the approximal surfaces.

The relationship between the incisor position and lingual surface morphology in normal occlusion.

This study aimed to investigate the relationship between the morphological characteristics of maxillary incisors and the anterior occlusion. The study materials comprised dental casts and lateral cephalograms of 26 modern Mongolian females with Angle Class I normal occlusion (mean age, 21 years 5 months). Computed tomography (CT) images of the dental casts were taken with an X-ray micro-CT system (SMX-100CT, Shimadzu, Kyoto Japan). The thickness of the marginal ridges and incisal edges, and the overjet and overbite, was measured on the three-dimensional images of the dental casts. On the lateral cephalogram, maxillary incisor to sella-nasion plane angle (U1 to SN angle), maxillary incisor to nasion-point A plane distance (U1 to NA distance), mandibular incisor to nasion-point B plane distance (L1 to NB distance), incisor mandibular plane angle, and interincisal angle were measured by tracing the left incisors of the maxilla and mandible. Spearman's single rank correlation coefficients were used to investigate any correlation between measurement items for each maxillary incisor. The thickness of the marginal ridges and incisal edges was positively correlated with the overbite. The thickness of the incisal edges was positively correlated with the irregularity index of the maxilla. There were significant negative correlations between overbite and U1 to SN angle, U1 to NA distance, and L1 to NB distance. Significant positive correlations were noted between the overbite and the overjet. In conclusion, there was no strong relationship between the morphological characteristics of maxillary incisors and the anterior occlusion.

Reliability of clinical crown center to predict marginal ridge leveling.

OBJECTIVE: To evaluate the null hypothesis that there is no difference between the vertical compensation necessary to level the clinical crown centers and that required to level the marginal ridges. MATERIALS AND METHODS: Initial dental casts selected from 200 patients that met the selection criteria were included. The vertical position of the clinical crown center (VPCC) and marginal ridge (VPMR) of posterior teeth were measured in both arches using a digital height gauge with 0.01mm precision. The vertical discrepancy between the clinical crown centers (VDCC) and marginal ridges (VDMR) of adjacent posterior teeth were calculated and compared. The significance level was set at P < .05. RESULTS: In general, vertical discrepancies between VDCC and VDMR were statistically significant (P < .05). Clinically significant differences were observed between the maxillary second premolar and first molar and between the mandibular molars. The VPCC was significantly and positively correlated with patient age. CONCLUSIONS: Differences between VDCC and VDMR showed that the VPCC may not be an accurate predictor of marginal ridge leveling because the vertical compensation necessary to level the VPCCs is not similar to that required to level the marginal ridges, requiring caution in its utilization, mainly in teenagers.

Sharp marginal ridge affects the fitness of the metal full crown cast for the abutment tooth / 医学研究生学报

Objective: To study the effect of the sharp marginal ridge of the abutment on the casting of the fit metal full crown in dental preparation.Methods: We established the models of the designed crown-based-teeth(American Dental Association style,No2 trail) with a sharp or smooth marginal ridge,and cast a metal crown for each model.We injected silicone into the crown and immediately fixed it onto each model.Then we took out the solidified silicone and measured its thickness between the crown and the occlusal face of each model.The thinner the thickness,the better the fitness.Results: The average silicone thickness was 250 ?m in the smooth marginal ridge group and 1 660 ?m in the sharp marginal ridge group,with significant difference in between(P

Crown angulations of posterior teeth of normal occlusion measured from marginal ridge plane / 대한치과교정학회지

In the previous studies about prescription of preadjusted appliance, occlusal plane was used as a reference plane for crwon angulation (tip) measurement But this reference plane is not parallel to the he connecting the facial axis points at which the centers of brackets are positioned (Andrews' plane), due to the curve of Spee. Therefore, we developed a new reference plane unaffected by the curve of Spee and more parallel to the Andrews' plane. It is an imaginary line connecting mesial and distal marginal ridges of each posterior tooth, and we named it 'marginal ridge plane'. In this study, crown angulations of posterior teeth of 29 normal occlusion samples were measured and measurements from both reference planes were compared. Crown angulation measurements measured from occlusal plane were different from crown angulation measurements from marginal ridge plane in the upper and lower 2nd molars (p<0.01), and 1st premolars (p<0.05). These results were analyzed as the crown angulation measurements from occlusal plane were affected by the curve of Spee. Crown angulations should be vaned according to the amount of curve of Spee to maintain- the continuity of marginal ridges. To solve this problem, determining bracket angulation as the bracket slot is parallel to the marginal ridge plane of each posterior teeth is recommended.