Impact of acquisition volume on cone beam computed tomography imaging of marginal bone: an ex vivo study.

OBJECTIVE: The current study explores whether there is a clinically relevant distinction in the measurement of marginal bone loss when comparing high-dose (HD) versus low-dose (LD) cone beam computed tomography (CBCT) protocols in small and large acquisition volumes.  Material and Methods: CBCTs of four human cadaveric preparates were taken in HD and LD mode in two different fields of view 8 × 8 cm2 (LV) and 5 × 5 cm2 (SV). In total, 43 sites of 15 teeth were randomly chosen, and marginal bone loss was measured twice in all protocols at 43 sites of 15 teeth by one calibrated investigator. Bland-Altman plots and Lin's concordance correlation coefficient (CCC) were calculated to assess the extent of agreement of the measurements. Additionally, the rater scored the certainty in each of the measurements. RESULTS: For HD-CBCT CCC of measurements obtained using SV versus LV was 0.991. CCC of measurements obtained using SV versus LV of LD-CBCT was 0.963. Both CCC values indicated excellent agreement between the two volumes in both protocols.  CCC also indicated high intramodality correlation between HD-CBCT and LD-CBCT independent of the acquisition volume (0.963 - 0.992). Bland-Altman plots also indicated no substantial differences. Results of certainty scoring showed significant differences (p = 0.004 (LV), p < 0.001(SV)) between the LD and HD-CBCT. CONCLUSIONS: Accuracy of measurements of bone loss shows no clinical noticeable effects depending on the CBCT volume in this ex vivo study. There appears to be no relevant advantage of SV over LV, neither in HD-CBCT nor in LD-CBCT and additionally no relevant advantage of HD versus LD in visualizing marginal bone loss.

Clinical evaluation of bulk-fill and universal nanocomposites in class II cavities: Five-year results of a randomized clinical split-mouth trial.

AIM: Evaluating the clinical survival and quality parameters of class-II restorations using 3M™ FiltekTM Bulk Fill Posterior Restorative compared to 3M™ FiltekTM Supreme XTE Universal Restorative over a period of five years. MATERIALS AND METHODS: A longitudinal, randomized, prospective split-mouth study with 60 patients (29 female, 31 male; mean age 44 y; range 20-77 y) and a total of 120 load-bearing class II restorations (TEST: n=60 Filtek Bulk Fill Posterior Restorative; CONTROL: n=60 Filtek Supreme XTE Universal Restorative) was conducted. Clinical evaluation was performed by blinded evaluators according to FDI criteria. Kaplan-Meier method was used for survival analysis and an intergroup comparison (Mann-Whitney-U-Test) was carried out. A basic significance level of 0.05 was corrected by the Bonferroni method to account for multiple testing (significance after correction: p<0.00067). RESULTS: The mean overall survival of restorations was 92% after 56.98±1.51 months in the TEST group (95 CI= 54.02;59.94) and 92% after 57.25±1.46 months (95 CI= 54.39; 60.12) in the CONTROL group (log-rank p=0.995). In total, four failures occurred in both TEST and CONTROL group during the observation period (mean annual failure rate: 1.6%). The most common reasons for failure were chipping-fractures, debonding, cracked-tooth-syndrome and recurrent decay. With regard to the FDI criteria, no significant differences between TEST and CONTROL material occurred for any of the evaluated variables. In the TEST group two restorations had to be repaired and two had to be replaced, in the CONTROL group four restorations had to be replaced. CONCLUSION: Both materials showed acceptable clinical performance and survival during the 5-year observation period. CLINICAL SIGNIFICANCE: The use of a nanofilled bulk-fill composite proved to be an aesthetically, functionally and biologically satisfactory alternative in posterior dentition.

A randomized clinical split-mouth trial of a bulk-fill and a nanohybrid composite restorative in class II cavities: Three-year results.

OBJECTIVES: The aim of this randomized controlled clinical trial was to evaluate the clinical survival and quality parameters of class-II restorations using a bulk-fill composite resin compared to a conventional nanohybrid composite resin in a split-mouth design. METHODS: One hundred and twenty direct restorations were placed in stress bearing class II cavities (n = 60 test group: Filtek™ Bulk Fill Posterior and n = 60 control group: Filtek™ Supreme XTE) in adult permanent teeth. Survival and clinical quality were evaluated at baseline and after 3 years using modified World Dental Federation (FDI) criteria. Participants and clinical evaluators were blinded relating to the group assignment of the restorations. RESULTS: Seventeen restorations (14.2%) were lost to follow-up, leading to 51 restorations available for survival analysis in the test group and 52 restorations in the control group. Seven restorations showed unfavorable events and were classified as failure. Four bulk-fill restorations failed due to tooth infracture (n = 1), chipping fractures (n = 2) and recurrent decay (n = 1), whereas three conventional nanohybrid composite restorations failed due to adhesive failure (n = 1), tooth infracture (n = 1) and chipping as well as recurrent decay (n = 1). The mean annual failure rate was 2.4% and 1.8%, respectively. The difference between test and control group was not significant (p = 0.7). Data on the detailed assessment of FDI criteria were available for n = 48 and n = 49 restorations, respectively. No significant differences between the two groups could be found regarding the assessment of esthetic, functional and biological properties. SIGNIFICANCE: Both materials showed similar clinical performance and survival. The use of bulk-fill composite proved to be an esthetically, functionally and biologically satisfactory alternative in the posterior dentition during the 3-year follow-up.

Imaging furcation defects with low-dose cone beam computed tomography.

Different cone beam computed tomography (CBCT) protocols have shown promising results for imaging furcation defects. This study evaluates the suitability of low-dose (LD)-CBCT for this purpose. Fifty-nine furcation defects of nine upper and 16 lower molars in six human cadavers were measured by a high-dose (HD)-CBCT protocol, a LD-CBCT protocol, and a surgical protocol. HD-CBCT and LD-CBCT measurements were made twice by two investigators and were compared with the intrasurgical measurements, which served as the reference. Furcation defect volumes generated from HD-CBCT and LD-CBCT imaging were segmented by one rater. Cohen's kappa and intraclass correlation coefficient (ICC) values were calculated to determine intra- and interrater reliability. The level of significance was set at α = 0.05. In total, 59 furcation defects of nine upper and 16 lower human molars were assessed. Comparing CBCT furcation defect measurements with surgical measurements revealed a Cohen's kappa of 0.5975 (HD-and LD-CBCT), indicating moderate agreement. All furcation defects identified by HD-CBCT were also detected by LD-CBCT by both raters, resulting in a Cohen's kappa of 1. For interrater agreement, linear furcation defect measurements showed an ICC of 0.992 for HD-CBCT and 0.987 for LD-CBCT. The intrarater agreement was 0.994(r1)/0.992(r2) for HD-CBCT and 0.987(r1)/0.991(r2) for LD-CBCT. The intermodality agreement was 0.988(r1)/0.991(r2). Paired t-test showed no significant differences between HD-CBCT and LD-CBCT measurements. LD-CBCT is a precise and reliable method for detecting and measuring furcation defects in mandibular and maxillary molars in this experimental setting. It has the potential to improve treatment planning and treatment monitoring with a far lower radiation dose than conventional HD-CBCT.

Can the Acid-formation Potential of Saliva Detect a Caries-related Shift in the Oral Microbiome?

PURPOSE: To determine acid-formation potential of saliva and evaluate whether this method corresponds with microbiome composition of individuals with and without caries. MATERIALS AND METHODS: A clinical, controlled pilot study was performed with two groups: individuals without caries (n = 25; DMFT = 0) and individuals with at least one active carious lesion (n = 25; DMFT>0). A detailed intraoral examination was performed, and the gingival bleeding index (GBI) and plaque index (PI) were recorded. The acid-formation potential was measured (ΔpH) after 1 h. Streptococcus mutans (SM) and lactobacilli (LB) were also quantified. Intergroup comparisons were made using the Mann-Whitney U-test. The diagnostic value was evaluated using the receiver operating characteristics (ROC) method and area under the curve (AUC) values were calculated. The saliva microbiome was analysed by 16S rDNA next-generation sequencing. RESULTS: A statistically significant difference was found in ΔpH, with the 'caries' group showing a higher mean value after 1 h ('healthy' = 1.1,'caries' = 1.4; p = 0.035). The AUC values were moderate to good (ΔpH = 0.67; SM = 0.83; LB = 0.83;1 = ideal). Streptococcus mutans and Lactobacilli were more frequently detected in the 'caries' group (p < 0.001), as were statistically significantly higher GBI (p = 0.006) and PI (p = 0.001). The saliva microbiome had a higher α-diversity and greater richness in individuals with active caries. The incidence of the genera Alloprevotella, Prevotella, Campylobacter and Veillonella was statistically significantly higher in the 'healthy' group. The incidence of the genera Fretibacterium, Lactobacillus, and Leptotrichia, as well as the phyla Spirochaetes and Synergistetes, was statistically significantly higher in the 'caries' group. CONCLUSION: Further studies must be carried out to determine the extent to which both tests are suitable for predicting future caries development.