Comparing the In Vivo Diagnostic Accuracy of Digital Periapical Radiography with Cone-beam Computed Tomography for the Detection of Vertical Root Fracture

Introduction

The purpose of this study was to determine whether there is a difference in the in vivo diagnostic accuracy of digital radiography (DR) and cone-beam computed tomography (CBCT) imaging in the detection of vertical root fracture (VRF). The presence/absence of VRF was confirmed by visual inspection of the extracted root surface and was the reference standard against which both imaging modalities were compared.

Methods

Twenty-one unsalvageable teeth from 20 patients that had been radiographed and scanned with CBCT imaging were included in the study. The teeth were atraumatically extracted and visually inspected under a microscope to confirm the presence/absence of fracture. The widest point of each fracture was recorded using an optical coherence tomography scanner in order to quantify the size of fractures. Images were viewed under standardized conditions by 13 examiners and repeated 2 weeks later to assess their consistency.

Results

DR and CBCT imaging showed similarly poor sensitivity of 0.16 and 0.27, respectively. Both imaging modalities had similarly high specificity of 0.92 and 0.83, respectively. There was no statistical difference between the diagnostic accuracy of either imaging modality. Fracture width did not affect the detection rate of either imaging modality. Receiver operating characteristic analysis revealed mean A_z values of 0.535 and 0.552 for DR and CBCT imaging, respectively.

Conclusions

Both DR and CBCT imaging have significant limitations when detecting vertical root fractures.     

Comparison of peri‐implant clinical and radiographic status around short (6 mm in length) dental implants placed in cigarette‐smokers and never‐smokers: Six‐year follow‐up results

Background

It is hypothesized that peri‐implant clinical and radiographic inflammatory parameters (probing depth [PD], bleeding on probing [BOP] and plaque index [PI]; and radiographic (crestal bone loss [CBL]) are worse among cigarette‐smokers (CS) compared with never‐smokers (NS) with short implants.

Purpose

The present 6‐year follow‐up retrospective study compared the peri‐implant clinical and radiographic parameters in CS and NS with short dental implants (6 mm in length).

Materials and methods

Fifty‐six male individuals were included. These individuals divided into 2 groups as follows: (a) Group‐1: 29 self‐reported systemically healthy CS with 48 short‐implants; and (b) Group‐2: 27 self‐reported systemically healthy NS with 43 short implants. Peri‐implant PD, PI, BOP, and CBL were measured. Group comparisons were done using the Kruskal‐Wallis test and sample size was estimated. Level of significance was set at P values < .05.

Results

In groups 1 and 2, the follow‐up durations were 6.2 ± 0.1 years and 6.1 ± 0.3 years, respectively. A cigarette smoking history of 8.9 ± 3.6 pack years was reported by individuals in Group‐1. At follow‐up, scores of peri‐implant PD, BOP, PI, and mesial and distal CBL were comparable around short implants in both groups.

Conclusion

Under strict oral hygiene maintenance protocols, short dental implants can remain functionally stable in CS in a manner similar to NS.     

Development of Noncarious Cervical Notch Lesions in Vitro

Abstract: Purpose : The initiation and progression of noncarious cervical notch lesions (NCCL) continues to perplex clinicians worldwide and poses a considerable restorative challenge. The purpose of this brief communication is to report what is believed to be the first in vitro production of notch-shaped lesions in the cervical third of premolar teeth.
Materials and Methods : The lesions, were produced by axial loading of selected permanent premolar teeth in a 10% aqueous solution of sulfuric acid over a period of 5 days, followed by immersion in water for 7 days.
Results : Results revealed macroscopic and microscopic features similar to those observed in noncarious cervical lesions in vivo. The lesions were incidental findings while the authors were studying stress corrosion of enamel at low pH. Although much remains to be investigated regarding the etiology and pathogenesis of NCCL, axial loading and a corrosive environment may be implicated in these processes. The artificial lesions arose in clinically sound teeth, suggesting that there is no simple clinical examination to identify teeth at risk from NCCL.     

Immunoglobulin kappa deleting element rearrangements are candidate targets for minimal residual disease evaluation in mantle cell lymphoma

Minimal residual disease (MRD) assessment is of high clinical relevance in patients with mantle cell lymphoma (MCL). In mature B-cell malignancies, the presence of somatic hypermutations (SHM) in Variable-Diversity-Joining Heavy chain (VDJH) rearrangements leads to frequent mismatches between primers, probes, and the target, thus impairing tumor cells quantification. Alternative targets, such as immunoglobulin kappa-deleting-element (IGK-Kde) rearrangements, might be suitable for MRD detection. We aimed at evaluating the applicability of IGK-Kde rearrangements for MRD quantification in MCL patients by real-time quantitative polymerase chain reaction (RQ-PCR)/digital-droplet-PCR (ddPCR). IGK screening was performed on bone marrow samples from two cohorts: the first from Turin (22 patients enrolled in the FIL-MCL0208 trial, NCT02354313) and the second from Rome (15 patients). IGK-Kde rearrangements were found in 76% (28/37) of cases, representing the sole molecular marker in 73% (8/11) of IGH-BCL1/IGH negative cases. MRD RQ-PCR monitoring was possible in 57% (16/28) of cases, showing a 100% concordance with the conventional targets. However, the frequent background amplification affected the sensitivity of the assay, that was lower in MCL compared to acute lymphoblastic leukemia and in line with multiple myeloma published results. ddPCR had a good concordance with RQ-PCR and it might help to identify false positive/negative results. From a clinical perspective, we suggest that IGK-Kde can be a candidate target for MRD monitoring and deserves a validation of its predictive value in prospective MCL series.     

Occlusal Changes Following Posterior Tooth Loss in Adults. Part 2. Clinical Parameters Associated with Movement of Teeth Adjacent to the Site of Posterior Tooth Loss

PURPOSE: Much anecdotal evidence is available on tooth positional changes following loss of an adjacent tooth, but only a few studies are available. In Part 1 of this series, supraeruption was assessed and Generalized Linear Models were made to determine the clinical parameters associated with the supraeruptive process. The models demonstrated that clinical parameters were not only associated with the extent of supraeruption, but also with the type of eruption present. This investigation of tooth positional changes adjacent to sites of posterior tooth loss attempts to provide increased understanding of the magnitude, direction, and associated features that may be helpful in decision making and treatment planning in the clinical setting. MATERIALS AND METHODS: One hundred patients with an unopposed posterior tooth, with 100 age, sex, and bone level matched controls, were drawn from patients undergoing routine restorative care at Leeds Dental Institute. Study models were scanned, and the extent of eruption, type of eruption of the unopposed tooth, the overbite, overjet, buccal occlusion, and degree of crowding in the dentition, tipping, rotation, and buccal movement of the teeth associated with the edentulous site were recorded. Generalized Linear Models were developed to examine associations between each tooth movement and patient or dental factors. RESULTS: A statistical significance in the degree of tipping of teeth both mesial and distal to the extraction site was detected between the subject and control groups. There was also a significant difference in rotation of the tooth mesial to the site. Four Generalized Linear Models were produced of the types of non-vertical movements found in teeth associated with sites of tooth loss. CONCLUSIONS: Teeth adjacent to the site of tooth loss may undergo non-vertical movements. Teeth mesial to the extraction site had a tendency to tip distally. The degree of tipping was increased in upper teeth and in subjects with a cusp-to-cusp buccal occlusion. Rotation of teeth mesial to the extraction site was more prevalent in the lower arch. Tipping of the tooth distal to the extraction site could be extreme and was found to be more prevalent in subjects with a reduced (Code 1) overbite and in the lower arch. Rotation of teeth distal to the extraction site was greater in the upper arch and was also associated with a reduced (Code 1) overbite. It also had an association with rotation of the tooth mesial to the extraction site. Models of non-vertical movement are likely to be of limited value due to overdispersion, indicating a high degree of variability within the model.     

Evaluation of the pH of a new carbonated soft drink beverage: An in vivo investigation

PURPOSE: Recently, a modified version of a successful soft drink has been developed that aims to reduce the potential for dental erosion in consumers. The aim of this investigation was to compare the effect of the modified and original formula soft drink on the pH at various tooth surfaces during and after ingestion in subjects without erosion. MATERIALS AND METHODS: Fifteen subjects (10 female and 5 male) without dental erosion drank both a modified and an unmodified beverage for over 5 minutes in a randomized order. Oral pH was measured with antimony electrodes positioned on the labial and palatal surfaces of an incisor and premolar and held in place by a close-fitting vacuum-formed appliance. The results were compared (using the Wilcoxon signed rank test, with matched pairs) for the percentage and total time that pH fell below 4, 5, and 5.5. RESULTS: The percentage and total time that pH fell below 4 was significantly different between the drinks (P <0.02), but the total time that pH fell below 5 and 5.5 was not. The time taken for subjects to return to pre-exposure pH levels in the mouth showed considerable variation between individuals. CONCLUSIONS: The modified-formula drink appeared to have less erosive potential than the original formula when assessed by measuring pH at the tooth surface. Although the erosive potential has been reduced by modifying the soft drink, it has not been eliminated.