Imaging furcation defects with low-dose cone beam computed tomography

Influence of Examiner Experience on the Measurement of Bone-Loss by Low-Dose Cone-Beam Computed Tomography: An Ex Vivo Study

The aim of this study was to investigate the influence of examiner experience on measurements of bone-loss using high-dose (HD) and low-dose (LD) CBCT. Three diagnosticians with varying levels of CBCT interpretation experience measured bone-loss from CBCT scans of three cadaveric heads at 30 sites, conducting measurements twice. Between the first and second measurements, diagnostician 2 and diagnostician 3 received training in LD-CBCT diagnostics. The diagnosticians also classified the certainty of their measurements using a three-grade scale. The accuracy of bone-loss measurements was assessed using the absolute difference between observed and clinical measurements and compared among diagnosticians with different experience levels for both HD and LD-CBCT. At baseline, there was a significant difference in measurement accuracy between diagnostician 1 and diagnostician 2, and between diagnostician 1 and diagnostician 3, but not between diagnostician 2 and diagnostician 3. Training improved the accuracy of both HD-CBCT and LD-CBCT measurements in diagnostician 2, and of LD-CBCT measurements in diagnostician 3. Regarding measurement certainty, there was a significant difference among diagnosticians before training. Training enhanced the certainty for diagnosticians 2 and 3, with a significant improvement noted only for diagnostician 3. Examiner experience level significantly impacts the accuracy and certainty of bone-loss measurements using HD- and LD-CBCT.

Vital root resection with radicular retrograde partial pulpotomy in furcation-involved maxillary molars in patients with periodontitis: Technique description and case series considering clinical and economic aspects

AIM

Conventional root resection in periodontally compromised furcation-involved maxillary molars requires preceding endodontic treatment and is therefore associated with loss of tooth vitality, higher invasiveness, treatment time and costs, and the risk of endodontic complications. Vital root resection (VRR) could overcome these disadvantages while establishing stable periodontal and endodontic conditions. This case series aimed to introduce the concept of one-stage VRR with radicular retrograde partial pulpotomy (VRRretro).

SUMMARY

Seven vital maxillary molars with residual probing pocket depths (PPD) ≥ 6 mm and furcation ≥ class 2 of five patients with stage III/IV periodontitis were treated with VRRretro using mineral trioxide aggregate. Teeth with residual through-and-through furcations were additionally tunnelled. Follow-up up to 2.5 years postoperatively during supportive periodontal care included full periodontal status, percussion and thermal sensitivity testing. Periapical radiographs were obtained to rule out possible periradicular radiolucencies. All seven treated molars were in-situ at an average of 26.84 ± 5.37 months postoperatively and were clinically and radiographically inconspicuous independent of tooth position, the resected root, the need for tunnelling and the restorative status. The mean PPD on the seven treated molars was 4.02 ± 0.85 mm (6-10 mm) preoperatively and 2.62 ± 0.42 mm (3-4 mm) at the last follow-up. Clinical attachment level and bleeding on probing could also be decreased. The teeth showed no mobility over time and furcations class 2 were reduced to class 1 while the tunnelled furcations were accessible with interdental brushes. All molars reacted negatively to percussion and positively to thermal sensitivity testing.

KEY LEARNING POINTS

In carefully selected cases considering patient- and tooth-related factors, VRRretro could be a promising treatment option to establish stable periodontal and endodontic conditions in furcation-involved maxillary molars while preserving tooth vitality.

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.

The "Dedicated" C.B.C.T. in Dentistry

This position statement represents a consensus of an expert committee composed by the Italian Academy of General Dentistry (Accademia Italiana Odontoiatria Generale COI-AIOG) and Italian Academy of Legal and Forensic Dentistry (Accademia Italiana di Odontoiatria Legale e Forense OL-F) on the appropriate use of cone beam computed tomography (C.B.C.T.) in dentistry. This paper analyzes the use of C.B.C.T. in light of the rapid evolution of volumetric technologies, with the new low- and ultra-low-dose exposure programs. These upgrades are determining an improvement in the precision and safety of this methodology; therefore, the need of a guideline revision of the use of C.B.C.T. for treatment planning is mandatory. It appears necessary to develop a new model of use, which, in compliance with the principle of justification and as low as reasonably achievable (ALARA) and as low as diagnostically acceptable (ALADA), can allow a functional "Dedicated C.B.C.T." exam optimized for the individuality of the patient.