Factors affecting the possibility to detect buccal bone condition around dental implants using cone beam computed tomography

The current role and future potential of digital diagnostic imaging in implant dentistry: A scoping review

OBJECTIVES

Diagnostic imaging is crucial for implant dentistry. This review provides an up-to-date perspective on the application of digital diagnostic imaging in implant dentistry.

METHODS

Electronic searches were conducted in PubMed focusing on the question 'when (and why) do we need diagnostic imaging in implant dentistry?' The search results were summarised to identify different applications of digital diagnostic imaging in implant dentistry.

RESULTS

The most used imaging modalities in implant dentistry include intraoral periapical radiographs, panoramic views and cone beam computed tomography (CBCT). These are dependent on acquisition standardisation to optimise image quality. Particularly for CBCT, other technical parameters (i.e., tube current, tube voltage, field-of-view, voxel size) are relevant minimising the occurrence of artefacts. There is a growing interest in digital workflows, integrating diagnostic imaging and automation. Artificial intelligence (AI) has been incorporated into these workflows and is expected to play a significant role in the future of implant dentistry. Preliminary evidence supports the use of ionising-radiation-free imaging modalities (e.g., MRI and ultrasound) that can add value in terms of soft tissue visualisation.

CONCLUSIONS

Digital diagnostic imaging is the sine qua non in implant dentistry. Image acquisition protocols must be tailored to the patient's needs and clinical indication, considering the trade-off between radiation exposure and needed information. growing evidence supporting the benefits of digital workflows, from planning to execution, and the future of implant dentistry will likely involve a synergy between human expertise and AI-driven intelligence. Transiting into ionising-radiation-free imaging modalities is feasible, but these must be further developed before clinical implementation.

Analysis of peri-implant bone defects by using cone beam computed tomography (CBCT): an integrative review

The objective of this work was to perform an integrative review of the inspection of peri-implant bone defects using cone beam computed tomography (CBCT). An electronic search was performed in the PubMed database using the following scientific terms: CBCT or Cone Beam computed tomography; dental implant; peri-implant; bone loss; defects. The survey identified 267 studies, of which 18 were considered relevant to this study. These studies provided important data taking into account the accuracy of cone beam computed tomography in the detection and measurement of peri-implant bone defects such as fenestrations, dehiscence and intraosseous circumferential defects. The effectiveness of CBCT in aiding in geometric bone calculations and in the diagnosis of peri-implant defects was influenced by factors such as artefacts, defect size, bone wall thickness, implant material, adjustment of acquisition parameters and observer experience. A not insignificant number of studies compared intraoral radiography to CBCT in the detection of peri-implant bone loss. CBCT was clearly superior to intraoral radiography in the detection of all peri-implant bone defects, except for defects located in the interproximal zone. In general, studies have shown that peri-implant bone measurements adjacent to the implant surface can be correctly determined, as well as the diagnosis of peri-implant bone defects with an average discrepancy of less than 1 mm from the actual measurement of the defect.

The precision of two alternative indirect workflows for digital model production: an illusion or a possibility?

OBJECTIVE

Despite the clear drive from both research and clinical dentistry toward digital transformation, there are limitations to implementing intra-oral scanning (IOS) into daily dental practice. This study aimed to compare the precision of digital models obtained from two alternative indirect workflows to direct IOS.

MATERIAL AND METHODS

Two indirect digital workflows were evaluated in this study. In the IOS group (direct), IOS directly obtained digital impressions of participants' upper and lower dental arches, while in the Scan Impression (Scan Imp) group (indirect), a desktop scanner scanned silicone-based impressions of upper and lower whole arches that were taken with plastic trays. In the cone-beam computed tomography impression (CBCT Imp) group (indirect), a CBCT machine scanned the silicone-based impressions. Then, the precision of the entire arch and individual teeth for all digital impressions was virtually quantified. Following superimposition, differences between standard tessellation language (STL) files obtained from both-direct and indirect-methods were evaluated by color-mapping and measuring the surface distance between superimposed STL files. Furthermore, 18 linear measurements were taken from each digital model. ANOVA with repeated measures, Pearson coefficient, and intraclass correlation coefficient were used for intergroup comparisons.

RESULTS

The digital models obtained from the two indirect workflows differed from the IOS in some dental and intra-arch measurements but were considered clinically acceptable. Ranked against IOS, CBCT Imp models had greater precision, followed by Scan Imp.

CONCLUSION

Digital models obtained from two indirect, alternative workflows, desktop, and CBCT scanning of impression, have clinically acceptable accuracy and reliability of tooth size and intra-arch measurements, providing the use of proper methodologies.

CLINICAL RELEVANCE

There are some limitations to implementing IOS in daily clinical practice. However, several alternative digital model production techniques might provide an affordable solution. Although they may insignificantly differ in accuracy, all can be applied clinically.

Comparative Evaluation of Implants with Different Surface Treatments Placed in Human Edentulous Mandibles: A 1-Year Prospective Study

The aims of this study were to analyze prospectively and comparatively the peri-implant bone crest levels, bone density, stability and success rate of implants with different surface treatments in human edentulous mandibles. Twenty edentulous patients were selected. Four different implants were placed between the mental foramen. Four groups were evaluated: (1) laser-modified surface (LASER), (2) surface modified by laser with deposition of apatites (LASER + HA), (3) surface modified by double acid etching (ACID, Implacil De Bortoli) and (4) surface modified by sandblasting and acid etching (SLActive®, Straumann). Clinical, radiographic, resonance frequency and tomographic analyses were used. After 4 months, mandibular fixed implant prostheses were installed. Clinical and radiographic analyses were performed at times T0 (immediately after implant placement), T1 (15 days), T2 (30 days), T3 (60 days), T4 (90 days), T5 (120 days), T6 (180 days) and T7 (360 days), post-implant placement. The resonance frequency analysis (RFA) was measured at T0, T4, T6 and T7. The tomographic analysis was performed at T0, T4 and T7. In the radiographic bone density analysis, a statistical difference was found between the SLActive® and LASER + HA groups at T4 (p < 0.05). Statistical differences were observed in RFA at T4 (90 days), between the SLActive® and LASER groups (p < 0.05) and between the SLActive® and LASER + HA groups (p < 0.05). At T6 and T7, statistical differences were found between the SLActive® group and all other implant surfaces (p < 0.01). The experimental surfaces analyzed showed encouraging positive outcomes compared to those of the SLActive® surface. Long-term follow-up should be performed to confirm these results.

The accuracy of probing, ultrasound and cone-beam CT scans for determining the buccal bone plate dimensions around oral implants - A systematic review

OBJECTIVE

The objective of this review was to assess the accuracy of available means of determining the BBT (buccal bone thickness) and/or BBL (buccal bone level). This was translated into the following research question: What is the accuracy of the available means of visualizing the BBP (buccal bone plate) to establish the BBT and/or the BBL, when compared to control measurements? As control measurements histomorphometric measurements, direct measurements and cone-beam computed tomography (CBCT) measurements in the absence of metal are accepted.

BACKGROUND DATA

METHODS: The literary search was performed by searching the databases of MEDLINE, Embase, and Web of Science, up to July 13, 2021. Types of studies included were clinical, in vitro and animal trials, specifically looking into the bone level and/or bone thickness of the buccal bone plate at oral implants. Reference lists were hand searched for relevant articles. Two reviewers performed the data extraction and analysis. Only studies using reliable control measurements to evaluate the accuracy of the tested means of visualizing BBT and/or BBL were included for analysis. The QUADAS-2 tool was used to perform bias analysis on the relevant studies. Extracted data was tabulated to show the differences between test and control measurements for BBT and BBL. For in vitro studies on CBCT measurements of BBT meta-analysis could be performed.

RESULTS

A total of 1176 papers were identified in the search. Twenty-two articles were used for data extraction and qualitative analysis. Of these studies nine were animal studies, 9 were in vitro studies and four were human studies. Six animal studies and three human studies provided data on probing. CBCT and sonography as techniques for visualizing the buccal bone plate. Probing at implant sites seems to provide data that correlates with a consistent distance from the BBP. Meta-analysis for probing studies could not be performed due to heterogeneity in the setups of these studies. Eleven studies on CBCT were eligible for inclusion. Of these three were animal studies, the remaining 8 studies were all in vitro studies. Meta-analysis was performed on the accuracy of CBCT for in vitro studies, finding a significant underestimation of the BBT when compared to control measurements by a mean difference of -0.15 mm with 95%CI [-0.26,-0.03]. Three studies were identified on measurement of BBT and/or BBL by sonography. This included one human study and two in vitro studies. The identified studies show a low error when determining the buccal bone level or thickness using sonography. All included studies possess a high risk of bias according to risk of bias analysis, mostly due to selection of the patient.

CONCLUSION

A strong limitation of this systematic review is the inclusion of different studies with heterogeneous designs. Within the limits of this analysis it cannot be concluded that probing is an accurate way of visualizing the BBP. CBCT cannot yet be recommended as a standard diagnostic tool for follow-up of the BBP at oral implants. The application of sonography as a diagnostic tool to visualize the BBP needs further scientific validation.

Preoperative buccal bone volume predicts long-term graft retention following augmentation in the esthetic zone: a retrospective case series

Objectives

Buccal bone augmentation in the esthetic zone is routinely used to achieve optimal clinical outcomes. Nonetheless, long‐term data are sparse, and it is unknown how baseline buccal bone volume affects the retention of the augmented volume over time.

Material and methods

This is a long‐term follow‐up retrospective case series. After a preoperative computed tomography scan, implants were placed in the anterior maxilla following guided bone regeneration, autogenous block grafting, or both. At the follow‐up, patients received a computed tomography scan and a clinical examination. Buccal bone volume was the primary outcome. Buccal bone thickness, peri‐implant, and esthetic parameters were secondary outcomes.

Results

After a median follow‐up of 6.7 years (interquartile range: 4.9–9.4), 28 implants in 19 patients (median age at augmentation: 43.3 years, interquartile range: 34.4–56.7, 53% female) were followed up. Preoperative buccal bone volume at baseline (V₀) showed a moderate correlation to final buccal bone volume (V_t, r_s = .43) but a strong correlation to the absolute volumetric change (ΔV = V_t–V₀, r_s = −.80). A linear mixed model for V_t had a large intercept of 91.39 (p < .001) and a rather small slope of .11 for V₀ (p = .11). Observed differences between treatments were not statistically significant in the mixed model. V₀ above 105 mm³ predicted a negative volume change (ΔV < 0) with a specificity of 100% and a sensitivity of 96%.

Conclusions

The results suggest higher gains in sites with lower V₀ and point to a cutoff V₀ above which the augmented volume is not retained long‐term.

Diagnostic performance of periapical and panoramic radiography and cone beam computed tomography for detection of circumferential gaps simulating osseointegration failure around dental implants: A systematic review

OBJECTIVE

The objective of this study was to appraise the diagnostic performance of periapical (PR) and panoramic (PANO) radiographs and cone beam computed tomography (CBCT) in detecting artificial circumferential gaps simulating osseointegration failure around dental implants in ex vivo studies.

STUDY DESIGN

Seven electronic databases and three gray literature sources were searched. Studies reporting diagnostic performance measures or data allowing calculation of those measures compared with the reference standard of in situ direct measurements were considered eligible. Either the area under the receiver operating characteristic curve or accuracy was chosen to summarize findings, with diagnostic performance interpreted as poor, acceptable, excellent, or outstanding. Risk of bias (RoB) was also assessed.

RESULTS

The ten included studies mostly suggested overall excellent to outstanding diagnostic capability with PR and CBCT. Various enhancement filters, CBCT voxel sizes, and/or fields of view were associated with acceptable to outstanding efficacy. PANO had the poorest results, with most research demonstrating acceptable to excellent discrimination. The RoB was high for seven studies, moderate for two, and low for -one.

CONCLUSIONS

PR and CBCT images were generally superior to PANO for the detection of artificial bone gaps. Results should be interpreted with caution because most studies had a high RoB.

Measuring peri-implant bone lesions using low-dose cone-beam computed tomography

PURPOSE

High-definition cone-beam computed tomography (HD-CBCT) offers superior image quality at the cost of higher radiation dose compared to low-dose CBCT (LD-CBCT). The aim of this study was to investigate whether peri-implant bone lesions can be accurately quantified using LD-CBCT, even when including the influence of surrounding tissues.

METHODS

Twelve titanium implants restored with all-ceramic crowns were placed in bovine bone, and peri-implant lesions were prepared. Radiographic imaging was performed using IR (intraoral radiography), HD-CBCT and LD-CBCT. To simulate the in-vivo situation, the samples were placed inside a dry human mandible, and a second LD-CBCT imaging was performed (LD-CBCT*). The datasets were presented to four observers in random order. Maximum lesion depth and width were measured in a standardized mesiodistal slice in IR, HD-CBCT, LD-CBCT, and LD-CBCT*. Mean lesion depth and width measurements for each sample in HD-CBCT served as reference.

RESULTS

Interrater agreement was slight for depth and excellent for width in HD-CBCT and both LD modes. For all observers, measurement deviations from HD-CBCT were below 0.3 mm in the LD protocols (LD-CBCT depth: 0.22 ± 0.17 mm, width: 0.22 ± 0.13 mm; LD-CBCT* depth: 0.24 ± 0.23 mm, width: 0.25 ± 0.21 mm) and at 0.4 mm in IR.

CONCLUSIONS

Absolute differences between LD-CBCT and HD-CBCT are small, although surrounding tissues decrease LD-CBCT image quality. Within the limitations of an in-vitro trial, LD-CBCT may become an adequate imaging modality for monitoring peri-implant lesions at a substantially decreased radiation dose.

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.

Accuracy of cone-beam computed tomography is limited at implant sites with a thin buccal bone: A laboratory study

BACKGROUND

To evaluate whether buccal bone thickness (BBT), implant diameter, and abutment/crown material influence the accuracy of cone-beam computed tomography (CBCT) to determine the buccal bone level at titanium implants.

METHODS

Two implant beds (i.e., narrow and standard diameter) were prepared in each of 36 porcine bone blocks. The implant beds were positioned at a variable distance from the buccal bone surface; thus, resulting in three BBT groups (i.e., >0.5 to 1.0; >1.0 to 1.5; >1.5 to 2.0 mm). In half of the blocks, a buccal bone dehiscence of random extent ("depth") was created and implants were mounted with different abutment/crown material (i.e., titanium abutments with a metal-ceramic crown and zirconia abutments with an all-ceramic zirconia crown). The distance from the implant shoulder to the buccal bone crest was measured on cross-sectional CBCT images and compared with the direct measurements at the bone blocks.

RESULTS

While abutment/crown material and implant diameter had no effect on the detection accuracy of the buccal bone level at dental implants in CBCT scans, BBT had a significant effect. Specifically, when BBT was ≤1.0 mm, a dehiscence was often diagnosed although not present, that is, the sensitivity was high (95.8%), but the specificity (12.5%) and the detection accuracy (54.2%) were low. Further, the average measurement error of the distance from the implant shoulder to the buccal bone crest was 1.6 mm.

CONCLUSIONS

Based on the present laboratory study, BBT has a major impact on the correct diagnosis of the buccal bone level at dental titanium implants in CBCT images; in cases where the buccal bone is ≤1 mm thick, detection of the buccal bone level is largely inaccurate.

Long-term clinical and radiographic results after treatment or no treatment of small buccal bone dehiscences at posterior dental implants: A randomized, controlled clinical trial

AIM

To test whether or not buccal vertical bone dehiscences (≤5 mm) around posterior implants left for spontaneous healing (SH) result in the same clinical and radiologic outcome as dehiscences treated with guided bone regeneration (GBR) at 7.5 years after implant placement (IMPL).

MATERIALS AND METHODS

Twenty-two patients receiving 28 posterior implants with a small non-contained buccal bone dehiscence (≤5 mm) were randomly assigned to the SH or the GBR group. Implants were loaded at 6 months. Clinical parameters (probing depths, sulcus bleeding index, plaque index) and approximal marginal radiographic bone levels were assessed regularly up to at least 6.8 years. The vertical extension of the dehiscences was measured clinically at IMPL and abutment connection and radiographically on cone beam computed tomographys at a mean follow-up time of 7.5 years.

RESULTS

Twenty patients with a total of 26 implants were recalled at 7.5 years (9.1% dropout). The implant/crown survival rates were 100% in both groups. Stable peri-implant tissues were observed in both groups showing only minimal signs of inflammation. During the entire study period (IMPL-7.5-year follow-up), the median buccal vertical bone gain measured 1.61 mm for the GBR group and 0.62 for the SH group showing no significant difference between the groups. Also, at 7.5 years, the median approximal marginal bone levels (GBR: 0.53; SH: 0.68) were not significantly different between the two groups (p = .61) while the remaining median buccal vertical dehiscences were larger in the SH group (2.51 mm) compared to the GBR group (1.66 mm; p = .02).

CONCLUSIONS

Implants with small non-contained buccal bone dehiscences exhibited high implant survival rates and healthy peri-implant tissues at 7.5 years. In the GBR group, the buccal vertical bone levels were higher compared to the SH group but remained stable over the entire study period for both treatments.

Detection of peri-implant bone defects using cone-beam computed tomography and digital periapical radiography with parallel and oblique projection

PURPOSE

To compare the diagnostic accuracy of cone-beam computed tomography (CBCT) with that of parallel (PPA) and oblique projected periapical (OPA) radiography for the detection of different types of peri-implant bone defects.

MATERIALS AND METHODS

Forty implants inserted into bovine rib blocks were used. Thirty had standardized bone defects (10 each of angular, fenestration, and dehiscence defects), and 10 were defect-free controls. CBCT, PPA, and OPA images of the samples were acquired. The images were evaluated twice by each of 2 blinded observers regarding the presence or absence and the type of the defects. The area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were determined for each radiographic technique. The 3 modalities were compared using the Fisher exact and chi-square tests, with P<0.05 considered as statistical significance.

RESULTS

High inter-examiner reliability was observed for the 3 techniques. Angular defects were detected with high sensitivity and specificity by all 3 modalities. CBCT and OPA showed similar AUC and sensitivity in the detection of fenestration defects. In the identification of dehiscence defects, CBCT showed the highest sensitivity, followed by OPA and PPA, respectively. CBCT and OPA had a significantly greater ability than PPA to detect fenestration and dehiscence defects (P<0.05).

CONCLUSION

The application of OPA radiography in addition to routine PPA imaging as a radiographic follow-up method for dental implantation greatly enhances the visualization of fenestration and dehiscence defects. CBCT properly depicted all defect types studied, but it involves a relatively high dose of radiation and cost.

Accuracy of cone-beam computed tomography, dental magnetic resonance imaging, and intraoral radiography for detecting peri-implant bone defects at single zirconia implants-An in vitro study

OBJECTIVES

To evaluate the diagnostic value of cone-beam computed tomography (CBCT), intraoral radiography (IR), and dental magnetic resonance imaging (dMRI) for detecting and classifying peri-implant bone defects at zirconia implants.

MATERIALS AND METHODS

Forty-eight zirconia implants were inserted in bovine ribs, 24 of which had standardized defects (1-wall, 2-wall, 3-wall, 4-wall) in two sizes (1 and 3 mm). CBCT, IR, and dMRI were performed and analyzed twice by four readers unaware of the nature of the defects. Cohen's and Fleiss' kappa (κ), sensitivity, and specificity were calculated for the presence/absence of bone defects, defect size, and defect type. Cochran's Q-test with post hoc McNemar was used to test for statistical differences.

RESULTS

A high intra- and inter-reader reliability (κ range: 0.832-1) and sensitivity/specificity (IR: 0.97/0.96; CBCT: 0.99/1; dMRI: 1/0.99) for bone defect detection were observed for all three imaging methods. For defect type classification, intra- (κ range: 0.505-0.778) and inter-reader (κ: 0.411) reliability of IR were lower compared to CBCT (κ range intrareader: 0.667-0.889; κ inter-reader: 0.629) and dMRI (κ range intrareader: 0.61-0.832; κ inter-reader: 0.712). The sensitivity for correct defect type classification was not significantly different for CBCT (0.81) and dMRI (0.83; p = 1), but was significantly lower for IR (0.68; vs. CBCT p = 0.003; vs. dMRI p = 0.004). The sensitivity advantage of CBCT and dMRI for defect classification was smaller for 1-mm defects (CBCT/dMRI/IR: 0.68/0.72/0.63, no significant difference) than for 3-mm defects (CBCT/dMRI/IR: 0.95/0.94/0.74; CBCT vs. IR p = 0.0001; dMRI vs. IR p = 0.003).

CONCLUSION

Within the limitations of an in vitro study, IR can be recommended as the initial imaging method for evaluating peri-implant bone defects at zirconia implants. CBCT provides higher diagnostic accuracy of defect classification at the expense of higher cost and radiation dose. Dental MRI may be a promising imaging method for evaluating peri-implant bone defects at zirconia implants in the future.

Accuracy of detecting and measuring buccal bone thickness adjacent to titanium dental implants-a cone beam computed tomography in vitro study

OBJECTIVES

The aim of this study was to assess the accuracy of detecting and measuring buccal bone thickness (BBT) adjacent to titanium implants in cone beam computed tomography (CBCT) images.

STUDY DESIGN

Titanium implants (1, 2, or 3), abutments, and metal-ceramic crowns were inserted into 40 bone blocks with various BBTs. CBCT images were acquired in various settings: Voxel sizes (0.2 and 0.13 mm) and reconstruction section thicknesses (2.0 and 5.0 mm) were assessed by 3 examiners. True BBT was measured in digital photographs of the bone blocks. Buccal bone detection was evaluated by sensitivity and specificity. BBT was evaluated by 1-way analysis of variance (ANOVA) between the true and the CBCT measurements and by calculating the difference between the true measurement and the CBCT measurement (Di-BBT).

RESULTS

Detection of buccal bone exhibited high sensitivity (0.86-1) and low specificity (0.14-1). More implants in the field of view, large voxel size, and thick image reconstruction sections had a negative impact on buccal bone detection. ANOVA showed statistically significantly larger BBT for the CBCT measurements in all settings (1.07-1.21 mm) compared with the true measurements (0.85 mm). Di-BBT was mostly within 0.5 mm.

CONCLUSIONS

BBT adjacent to titanium implants is overestimated when evaluated on CBCT cross-sectional images.

Diagnostic performance of cone beam computed tomography in assessing peri-implant bone loss: A systematic review

OBJECTIVES

To evaluate the diagnostic performance of cone beam computed tomography (CBCT) in the assessment of peri-implant bone loss and analyze its influencing factors.

MATERIALS AND METHODS

Clinical and preclinical studies reporting diagnostic outcomes of CBCT imaging of peri-implant bone loss compared to direct reference measurements were sought by searching five electronic databases, PubMed, MEDLINE, EMBASE, Web of Science, and CINAHL Plus, and OpenGrey. QUADAS-2 criteria were adapted for quality analysis of the included studies. A qualitative synthesis was performed. Two meta-analysis models (random-effects and mixed-effects) summarized the area under receiver operating characteristic (AUC) curve observations reported in the selected studies. The mixed-effects meta-analysis model evaluated three possible influencing factors, "defect type," "defect size," and "study effect."

RESULTS

The initial search yielded 3,716 titles, from which 18 studies (13 in vitro and 5 animal) were included. Diagnostic accuracy of CBCT was fair to excellent in detecting in vitro circumferential-intrabony and fenestration defects, but moderate to low for peri-implant dehiscences, and tended to be higher for larger defect sizes. Both, over- and underestimation of linear measurements were reported for the animal models. The meta-analyses included 37 AUC observations from eight studies. The random-effects model showed significant heterogeneity. The mixed-effects model exhibited also significant but lower heterogeneity, and "defect type" and "study effect" significantly influenced the variability of AUC observations.

CONCLUSION

In vitro, CBCT performs well in detecting peri-implant circumferential-intrabony or fenestration defects but less in depicting dehiscences. Influencing factors due to other site-related and technical parameters on the diagnostic outcome need to be addressed further in the future studies.

Intraobserver and interobserver reproducibility in linear measurements on axial images obtained by cone-beam computed tomography

PURPOSE

This study was performed to investigate the intra- and inter-observer variability in linear measurements with axial images obtained by PreXion (PreXion Inc., San Mateo, USA) and i-CAT (Imaging Sciences International, Xoran Technologies Inc., Hatfield, USA) CBCT scanners, with different voxel sizes.

MATERIALS AND METHODS

A cylindrical object made from nylon with radiopaque markers (phantom) was scanned by i-CAT and PreXion 3D devices. For each axial image, measurements were taken twice in the horizontal (distance A-B) and vertical (distance C-D) directions, randomly, with a one-week interval between measurements, by four oral radiologists with five years or more experience in the use of these measuring tools.

RESULTS

All of the obtained linear measurements had lower values than those of the phantom. The statistical analysis showed high intra- and inter-observer reliability (p=0.297). Compared to the real measurements, the measurements obtained using the i-CAT device and PreXion tomography, on average, revealed absolute errors ranging from 0.22 to 0.59 mm and from 0.23 to 0.63 mm, respectively.

CONCLUSION

It can be concluded that both scanners are accurate, although the linear measurements are underestimations, with no significant differences between the evaluators.