Detectability of experimental peri-implant cancellous bone lesions using conventional and direct digital radiography

Challenges in detecting various peri-implant bone defects on modified intraoral oblique radiographic projections: evaluation of an artificial mandibular model

OBJECTIVE

The objective of this study was to evaluate the effectiveness of oblique radiographic projection using the intraoral paralleling technique in detecting various peri-implant bone defects.

METHODS

Artificial mandibular models with appropriate radiopacity were created. An alveolar bone model without bone defects and models with 12 types of peri-implant bone defects (buccal, circumferential, and mixed types with different widths and depths) were created. A total of 273 images were obtained with orthoradial projections and 10-, 20-, and 30-degree oblique projections using a modified receptor holder. Two observers independently evaluated the images to detect bone defects. The grayscale values (GVs) of the peri-implant region and the adjacent area were measured and compared. The relationship between the GV and the observers' results was examined. The area under the curve (AUC) and inter-observer agreement were calculated.

RESULTS

Circumferential and mixed bone defects were detected on the orthoradial projections, while buccal defects were not detected. However, the detection of buccal defects was markedly improved using the oblique projections. In particular, the highest detection rates were obtained using the 20-degree oblique projection. There were no significant correlations between the GV and the bone defect detection rate. The AUCs for the two observers were 0.712 and 0.669. The inter-observer agreement was 0.502.

CONCLUSIONS

Compared with orthoradial projections, the use of oblique projection images greatly improved the ability of observers to detect peri-implant bone defects on the buccal side. The results provide new evidence for the selection of radiographic images in the follow-up of implant treatment.

Comparison of periapical parallel radiography with cbct with different field of views (FOV) for the detection of periapical lesions

Background

Chronic apical periodontitis (AP) may influence the outcome of root canal treatment. Thus, it is important to diagnose AP using the best method available. This research was done to compare the diagnostic accuracy of parallel periapical radiography (PR) and different field of views (FOVs) of cone-beam computed tomography (CBCT).

Materials and Methods

This ex vivo study was done on six human mandibles. After extraction of the teeth, periapical lesions with different sizes were prepared randomly by drilling a hole at the base of the socket using a bur. From among 67 sockets, 21 sockets had no lesion (control); then, all mandibles were scanned by CBCT with different FOVs and paralleling periapical technique radiography. The images were assessed by two examiners. The quantitative data were analyzed by intraclass correlation coefficient (ICC) and the qualitative data were analyzed by McNemar's test (α = 0.05). Sensitivity, specificity, and accuracy were calculated. Inter-observer agreement was assessed using kappa statistics for qualitative data and ICC for quantitative data.

Results

The quantitative scores were compared with the gold standard using ICC, which showed maximum agreement for the dental FOV of CBCT (93.3) and minimum agreement for PR (62.5) (P < 0.001). For qualitative data, maximum agreement was found for the dental FOV of CBCT (97.1%), and minimum agreement was reported for PR (59.7%). Kappa values were variable between 0.271 and 0.924 (P < 0.001). Maximum sensitivity was found for the dental FOV of CBCT (96%) and minimum sensitivity was observed for PR (51%). The inter-observer agreement was 0.922 for qualitative data and 0.90 for quantitative data (P < 0.001). There were no significant differences between CBCT with different FOVs and defect sizes (gold standard) while we found significant differences for periapical by defect sizes.

Conclusion

CBCT with dental FOV presents the highest sensitivity and diagnostic accuracy for detection and characterization of simulated AP.

Diagnostic accuracy of imaging examinations for peri-implant bone defects around titanium and zirconium dioxide implants: A systematic review and meta-analysis

Purpose

This systematic review and meta-analysis assessed the diagnostic accuracy of imaging examinations for the detection of peri-implant bone defects and compared the diagnostic accuracy between titanium (Ti) and zirconium dioxide (ZrO₂) implants.

Materials and Methods

Six online databases were searched, and studies were selected based on eligibility criteria. The studies included in the systematic review underwent bias and applicability assessment using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool and a random-effect meta-analysis. Summary receiver operating characteristic (sROC) curves were constructed to compare the effect of methodological differences in relation to the variables of each group.

Results

The search strategy yielded 719 articles. Titles and abstracts were read and 61 studies were selected for full-text reading. Among them, 24 studies were included in this systematic review. Most included studies had a low risk of bias (QUADAS-2). Cone-beam computed tomography (CBCT) presented sufficient data for quantitative analysis in ZrO₂ and Ti implants. The meta-analysis revealed high levels of inconsistency in the latter group. Regarding sROC curves, the area under the curve (AUC) was larger for the overall Ti group (AUC=0.79) than for the overall ZrO₂ group (AUC=0.69), but without a statistically significant difference between them. In Ti implants, the AUCs for dehiscence defects (0.73) and fenestration defects (0.87) showed a statistically significant difference.

Conclusion

The diagnostic accuracy of CBCT imaging in the assessment of peri-implant bone defects was similar between Ti and ZrO₂ implants, and fenestration was more accurately diagnosed than dehiscence in Ti implants.

Intra- and inter-observer agreements in detecting peri-implant bone defects between periapical radiography and cone beam computed tomography: A clinical study

Background/purpose

Information regarding agreements between periapical radiograph (PA) and cone beam computed tomography (CBCT) in detecting peri-implant defect is still scarce. The aim of this clinical study was to compare agreements between PA and CBCT in detecting peri-implant bone defect.

Materials and methods

This retrospective clinical study enrolled 32 patients with both PA and CBCT filmed right after implant placement. Four modalities were used for film reading: PA1 (original), PA2 (enhanced brightness/contrast), CBCT1 (selected axial and mesial-distal direction images) and CBCT2 (all data with software). 2 experienced and 2 inexperienced observers scored all films. Intra- and inter-observer agreements were estimated with Cohen's kappa coefficient. Categorized agreements were compared and differences among four modalities were calculated.

Results

Agreements of PA were better than CBCT when detecting peri-implant bone defects in inter-observer agreements (median kappa 0.471 vs. 0.192; p = 0.016). Moreover, agreements in experienced observers were better than inexperienced observers (median kappa 0.883 vs. 0.567; p < 0.001). There was significant difference among four modalities except for experienced observer 2 (p = 0.218).

Conclusion

Agreements of PA are better than CBCT when detecting peri-implant bone defects, especially for inter-observer agreements. Experienced observers are more consistent in assessment than inexperienced ones.

Comparison of the different voxel sizes in the estimation of peri-implant fenestration defects using cone beam computed tomography: an ex vivo study

Background

To examine the influence of voxel sizes to detect of peri-implant fenestration defects on cone beam computed tomography (CBCT) images.

Materials and methods

This study performed with three sheep heads both maxilla and mandible and two types of dental implant type 1 zirconium implant (Zr⁴⁰) (n = 6) and type 2 titanium implant (Ti²²) (n = 10). A total of 14 peri-implant fenestrations (8 buccal surfaces, 6 palatal/lingual surface) were created while 18 surfaces (8 buccal, 10 palatal/lingual) were free of fenestrations. Three observers have evaluated the images of fenestration at each site. Images obtained with 0.75 mm³, 0.100 mm³, 0.150 mm³, 0.200 mm³, and 0.400 mm³ voxel sizes. For intra- and inter-observer agreements for each voxel size, Kappa coefficients were calculated.

Results

Intra- and inter-observer kappa values were the highest for 0.150 mm³, and the lowest in 0.75 mm³ and 0.400 mm³ voxel sizes for all types of implants. The highest area under the curve (AUC) values were found higher for the scan mode of 0.150 mm³, whereas lower AUC values were found for the voxel size for 0.400 mm³. Titanium implants had higher AUC values than zirconium with the statistical significance for all voxel sizes (p ≤ 0.05).

Conclusion

A voxel size of 0.150 mm³ can be used to detect peri-implant fenestration bone defects. CBCT is the most reliable diagnostic tool for peri-implant fenestration bone defects.

Using acrylic customized X-ray positioning stents for long-term follow-up studies

Objectives

Long-term assessment of teeth, dental implants, and their corresponding structures is vital to obtain more data concerning the achievement or disappointment of different treatment modalities in clinical situations.

Aim

This report aimed to verify the usage of customized X-ray positioning stents suitable for long-term follow-up studies.

Material and methods

Two acrylic stents were compared. An X-ray positioning device was built by the incorporation of a bite piece within an acrylic hard nightguard stent and a conventional acrylic film holder were fabricated for 20 patients. Four radiographs were taken of each patient (two of each film holder) at the initial time and after 3 months. Specific linear measurements of the premolar diameter (CEJ width) and the height between the CEJ and the apex were made of all of the radiographs to determine the reproducibility and accuracy of the procedure.

Results

The customized X-ray positioning positing stent showed a slight increase in the mean difference of the measurements of the value of the real ratio, demonstrating that the measurements were precise and reliable images of the premolars. The acrylic film holder showed a significant difference in the measurements of the value of the real ratio, indicating unreliable images of the premolars.

Conclusion

The device provided reliable linear measurements and produced reproducible images suitable for studies depending on the follow-up analysis.

Does the implant-abutment interface interfere on marginal bone loss? A systematic review and meta-analysis

The objective of this systematic review was to compare the conical internal connection (IC) with the external hexagonal connection (EH) on the occurrence of marginal bone loss (ΔMBL). Different databases were used to carry out the selection of the elected studies. The studies were judged according to the risk of bias as "high", "low" and "unclear" risk. For the meta-analysis we included only studies that could extract the data of ΔMBL, survival rate (SR) and probing depth (PD). No statistically significant differences were found for ΔMBL data at one, three- and five-year survival rates between implant connections (p <0.05), however statistically significant differences were found for PD between EH and IC implants (1-year follow-up) -0.53 [95%CI -0.82 to -0.24, p = 0.0004]. This present systematic review demonstrated that there are no significant differences between IC and EH implants for both ΔMBL and SR at 1, 3 e 5 years after functional loading, although better PD values were observed for implants pertaining to the IC connections. Considering the high heterogeneity, more well-delineated, randomized clinical trials should be conducted.

Effect of digital noise reduction on the accuracy of endodontic file length determination

PURPOSE

The aim of the present study was to evaluate the measurement accuracy of endodontic file length on periapical digital radiography after application of noise reduction digital enhancement.

MATERIALS AND METHODS

Thirty-five human single-rooted permanent teeth with canals measuring 20-24 mm in length were selected. ISO #08 endodontic files were placed in the root canals of the teeth. The file lengths were measured with a digital caliper as the standard value. Standard periapical digital images were obtained using the Digora digital radiographic system and a dental X-ray unit. In order to produce the enhanced images, the noise reduction option was applied. Two blinded radiologists measured the file lengths on the original and enhanced images. The measurements were compared by repeated measures ANOVA and the Bonferroni test (α=0.05).

RESULTS

Both the original and enhanced digital images provided significantly longer measurements compared with the standard value (P<0.05). There were no significant differences between the measurement accuracy of the original and enhanced images (P>0.05).

CONCLUSION

Noise reduction digital enhancement did not influence the measurement accuracy of the length of the thin endodontic files on the digital periapical radiographs despite the fact that noise reduction could result in the elimination of fine details of the images.