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Objectives: This study investigates effects of surgical guide manufacturing process on 3D transfer accuracy of planned dental implant position, using three production methods: additive 3D‐printed (3DF), subtractive milled (MF), and analog laboratory fabricated templates (LF). Material and Methods: Implant position for a single‐tooth gap (#26) planned digitally. 3DF and MF templates were designed digitally, while LF templates were analogously created. For each manufacturing type, 10 surgical guides were fabricated. Each guide was used for template‐guided implant placement in model replicas. For evaluation of implant placement, cone beam computed tomography scans of all implanted models were superimposed, and implant positions were determined. Deviations at implant shoulder/apex were measured, and median and inter‐quartile range (IQR) were determined for mesio‐distal, oro‐facial, coronal apico, 3D spaces, and angles. Results: At implant shoulder, vertical components dominated position deviations (up to 1.04 mm, IQR 0.28 mm for 3DF). Horizontal deviations were much lower (mesio‐distally up to 0.38 mm, IQR 0.36 mm (LF)). Implant apex shows similar vertical deviations, while horizontal deviations clearly increased compared to shoulder, especially in mesio‐distal direction. Median angular deviations were between 2.1° (IQR 2.0 mm, max. 4.2°) for 3DF and 3.3° (IQR 1.9 mm, max. 5.3°) for MF. No statistical differences were found between manufacturing types (Kruskal–Wallis test, p =.05). Conclusions: The study showed the method of implant guide fabrication did not affect the accuracy of implant placement within the limits of an in vitro environment. All methods resulted in implant placement which did not exceed the accepted safety deviation envelope (1.5–2.0 mm). [ABSTRACT FROM AUTHOR]

Objective: To identify the different uses and modalities of digital technologies to diagnose, plan and monitor peri‐implant soft tissue conditions and aesthetics. Methods: A comprehensive narrative review of pertinent literature was conducted, critically appraising key digital technologies that may assist peri‐implant soft tissue augmentation and assessment. An electronic search on four databases including studies published prior to 1st July 2023 was performed and supplemented by a manual search. Results: Predominantly, tools such as cone beam computed tomography (CBCT), intraoral scanning (iOS), intraoral ultrasonography and digital spectrophotometry were commonly to assess and monitor peri‐implant soft tissues. The main clinical and research applications included: (i) initial assessment of mucosal thickness, supra‐crestal tissue height and keratinized mucosa width, (ii) evaluation of peri‐implant soft tissue health and inflammation, (iii) monitoring profilometric changes and midfacial mucosal margin stability over time and (iv) aesthetic evaluation through colour assessment. While evidence for some digital tools may be limited, the integration of digital technologies into peri‐implant soft tissue management holds great promise. These technologies offer improved precision, comfort and speed in assessment, benefiting both patients and clinicians. Conclusion: As digital technologies progress, their full potential in peri‐implant soft tissue augmentation and their value will become more evident with ongoing research. Embracing these innovations and their potential benefits is recommended to ensure that during progress in implant dentistry, patient care is not hindered. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the accuracy and reliability of deep learning in automatic graft material segmentation after maxillary sinus augmentation (SA) from cone‐beam computed tomography (CBCT) images. Materials and Methods: One hundred paired CBCT scans (a preoperative scan and a postoperative scan) were collected and randomly allocated to training (n = 82) and testing (n = 18) subsets. The ground truths of graft materials were labeled by three observers together (two experienced surgeons and a computer engineer). A deep learning model including a 3D V‐Net and a 3D Attention V‐Net was developed. The overall performance of the model was assessed through the testing data set. The comparative accuracy and inference time consumption of the model‐driven and manual segmentation (by two surgeons with 3 years of experience in dental implant surgery) were conducted on 10 CBCT scans from the test samples. Results: The deep learning model had a Dice coefficient (Dice) of 90.36 ± 2.53%, a 95% Hausdorff distance (HD) of 1.59 ± 0.82 mm, and an average surface distance (ASD) of 0.38 ± 0.11 mm. The proposed model only needed 7.2 s, while the surgeon took 19.15 min on average to complete a segmentation task. The overall performances of the model were significantly superior to those of surgeons. Conclusions: The proposed deep learning model yielded a more accurate and efficient performance of automatic segmentation of graft material after SA than that of the two surgeons. The proposed model could facilitate a powerful system for volumetric change evaluation, dental implant planning, and digital dentistry. [ABSTRACT FROM AUTHOR]

Objectives Materials and Methods Results Conclusions To evaluate the influence of multiplanar reconstruction thickness on the detection of peri‐implant bone defects with a standalone zirconia implant and compare it to when another implant is in the vicinity using cone‐beam computed tomography (CBCT).Five dry human mandibles were used to create twenty implant sites in the second premolar and first molar regions. The OP300 Maxio was used to acquire CBCT images (90 kVp, 6.3 mA, 5 × 5 cm FOV, and 0.125 mm3 voxel size) before and after creating 3 mm peri‐implant bone defects in the buccal aspect of the premolar region. Half of the scans featured a single zirconia implant in the premolar region, while the others had two implants in the premolar and molar regions. Three reconstruction thicknesses (0.125 mm, 1 mm, and 2 mm) were considered for the multiplanar reconstruction analyses. Five oral and maxillofacial radiologists assessed the detection of peri‐implant bone defects using a 5‐point scale. Diagnostic parameters were calculated and compared using Two‐way ANOVA (α = .05).The studied factors showed no significant influence on the diagnosis of peri‐implant bone defects (p > .05). Diagnostic performance was notably higher with a single implant, especially with a 2‐mm reconstruction thickness (AUC = 0.88, sensitivity = 0.68, specificity = 0.94). Although the differences were not statistically significant, the results were more modest when two implants were present (AUC = 0.80, sensitivity = 0.58, specificity = 0.82).The presence of an adjacent zirconia implant and variations in reconstruction thickness did not influence the detection of 3 mm buccal peri‐implant bone defects on CBCT images. [ABSTRACT FROM AUTHOR]

Aim Materials and Methods Results Conclusion To evaluate the performance of low‐dose cone beam computed tomography (CBCT) protocols with regard to linear bone measurements in the posterior mandible for implant planning compared with higher dose protocols.Forty‐two edentulous posterior sites in human cadaveric mandibles were imaged in three CBCT scanners using three or four protocols with varying exposure parameters to achieve lower dose. Co‐registration was performed to generate sagittal and cross‐sectional image sections representative of the implant site. Three observers measured bone height, from the alveolar crest to the mandibular canal, and width, three mm from the top of the alveolar crest. Intra‐ and interobserver reproducibility were assessed for the cases rated as nonmeasurable as well as for completed measurements. The measurements were analyzed using paired t‐tests for differences among the CBCT protocols and the frequency distribution of nonmeasurable cases with a Pearson Chi‐square test.Reproducibility for registering nonmeasurable cases varied among observers; however, no consistent significant differences were found in the frequency distribution of these cases among observers, units, and protocols. Intraclass correlation coefficients (ICC) were >0.9 for all measurements of bone height and width. Mean differences of <0.5 mm were found regardless of protocol; however, one observer did in some cases produce larger differences.Linear bone measurements did not differ significantly and could be performed with excellent reliability, using low‐dose CBCT protocols compared with standard and high‐resolution ones. Varying approaches for rating nonmeasurable cases were found, indicating differences in diagnostic strategies related to implant planning among observers. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study is to investigate the association of peri‐implantitis (PI) and sinus membrane thickening and to assess the resolution of membrane thickening following intervention (implant removal or peri‐implantitis treatment) aimed at arresting PI. Materials and Methods: Forty‐five patients with 61 implants in the posterior maxillary region were retrospectively included in the study. Twenty‐four patients were diagnosed with peri‐implantitis (PI) and 21 had peri‐implant health (PH). Cone‐beam computed tomography (CBCT) scans were evaluated to assess maxillary sinus characteristics, including membrane thickening, sinus occupancy and ostium patency. The CBCT scans taken 6 months after intervention aimed at arresting disease (implant removal or treatment of PI) in the PI group were also appraised and compared to baseline scans. Results: At baseline, all parameters evaluating membrane thickness disorders yielded significant differences between groups (p <.001). Patients with posterior maxillary implants diagnosed with PI were 7× more likely to present membrane thickening compatible with pathology when compared to patients with healthy implants (OR = 7.14; p =.005). Furthermore, the likelihood was 6x greater in implants diagnosed with PI to exhibit moderate membrane thickening (OR = 6.75, p =.001). The patients receiving interventions aimed at arresting PI experienced significant enhancement in all radiographic parameters related to the sinus cavity at the 6‐month follow‐up (p <.001), though these variations were similarly independent of whether treatment consisted of PI treatment or implant removal. Conclusions: Maxillary sinus membrane thickening and the permeability/obstruction of the ostium are frequently associated with the presence of PI in posterior implants. Interventions targeting disease resolution effectively reduce membrane thickness to levels compatible with maxillary sinus health. [ABSTRACT FROM AUTHOR]

Objectives: The present study was conducted to evaluate the reproducibility of Lekholm and Zarb classification system (L&Z) for bone quality assessment of edentulous alveolar ridges and to investigate the potential of a data‐driven approach for bone quality classification. Materials and Methods: Twenty‐six expert clinicians were asked to classify 110 CBCT cross‐sections according to L&Z classification (T0). The same evaluation was repeated after one month with the images put in a different order (T1). Intra‐ and inter‐examiner agreement analyses were performed using Cohen's kappa coefficient (CK) and Fleiss' kappa coefficient (FK), respectively. Additionally, radiomic features extraction was performed from 3D edentulous ridge blocks derived from the same 110 CBCTs, and unsupervised clustering using 3 different clustering methods was used to identify patterns in the obtained data. Results: Intra‐examiner agreement between T0 and T1 was weak (CK 0.515). Inter‐examiner agreement at both time points was minimal (FK at T0: 0.273; FK at T1: 0.243). The three different unsupervised clustering methods based on radiomic features aggregated the 110 CBCTs in three groups in the same way. Conclusions: The results showed low agreement among clinicians when using L&Z classification, indicating that the system may not be as reliable as previously thought. The present study suggests the possible application of a reproducible data‐driven approach based on radiomics for the classification of edentulous alveolar ridges, with potential implications for improving clinical outcomes. Further research is needed to determine the clinical significance of these findings and to develop more standardized and accurate methods for assessing bone quality of edentulous alveolar ridges. [ABSTRACT FROM AUTHOR]

Objectives: To systematically analyze the accuracy of robotic surgery for dental implant placement. Materials and Methods: PubMed, Embase, and Cochrane CENTRAL were searched on October 25, 2023. Model studies or clinical studies reporting the accuracy of robotic surgery for dental implant placement among patients with missing or hopeless teeth were included. Risks of bias in clinical studies were assessed. Meta‐analyses were undertaken. Results: Data from 8 clinical studies reporting on 109 patients and 242 implants and 13 preclinical studies were included. Positional accuracy was measured by comparing the implant plan in presurgery CBCT and the actual implant position in postsurgery CBCT. For clinical studies, the pooled (95% confidence interval) platform deviation, apex deviation, and angular deviation were 0.68 (0.57, 0.79) mm, 0.67 (0.58, 0.75) mm, and 1.69 (1.25, 2.12)°, respectively. There was no statistically significant difference between the accuracy of implants placed in partially or fully edentulous patients. For model studies, the pooled platform deviation, apex deviation, and angular deviation were 0.72 (0.58, 0.86) mm, 0.90 (0.74, 1.06) mm, and 1.46 (1.22, 1.70)°, respectively. No adverse event was reported. Conclusion: Within the limitation of the present systematic review, robotic surgery for dental implant placement showed suitable implant positional accuracy and had no reported obvious harm. Both robotic systems and clinical studies on robotic surgery for dental implant placement should be further developed. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the esthetic outcome, as well as clinical, radiographic, and volumetric tissue alterations 1 year after immediate implant placement (IIP) with connective tissue grafting (CTG) versus dual‐zone concept (DZ) at sites with thin labial bone in the esthetic zone. Materials and Methods: This randomized clinical trial included 30 patients treated with IIP simultaneous with either CTG or DZ (n = 15 each). Pink esthetic score (PES) was assessed 6 months after crown placement as the primary outcome. Amount of bone labial to the implant, labio‐palatal ridge reduction, and crestal bone changes were measured via CBCT after 1 year. Volumetric analysis of linear labial soft tissue contour, interdental, and mid‐facial soft tissue level changes, and total volume loss (mm3) were measured after 1 year. Results: Similar PES was observed in the CTG (12.53 ± 1.13) and DZ (12.13 ± 1.55) groups, with no significant difference (p = 0.42). Likewise, there were no statistically significant differences found between the two groups in labio‐palatal bone reduction (mm&%), interdental papillae, and mid‐facial gingival levels (p > 0.05). However, the mean vertical crestal bone changes in the CTG and DZ groups were −1.1 ± 0.6 mm and 0.2 ± 1.0 mm, respectively, with a statistically significant difference (p = 0.0002). Moreover, CTG revealed less linear and total volume (mm3) loss in the labial soft tissue which was statistically significant compared to DZ (p = 0.007). Conclusion: Both groups demonstrated the same PES, nevertheless, volumetric analysis revealed twice total labial volume loss in DZ compared to CTG. It might be concluded that the use of CTG with IIP caused less horizontal reduction in the supra‐implant complex compared to the DZ. [ABSTRACT FROM AUTHOR]

Objective: To assess the radiological and histological outcome after horizontal guided bone regeneration (GBR) with deproteinized bovine bone mineral (DBBM) alone or in combination with particulate autogenous bone (PAB). Materials and Methods: Eighteen edentulous patients with an alveolar ridge of ≤4 mm were included in this split‐mouth randomized controlled trial. Horizontal GBR with a graft composition of 100% DBBM (100:0) on one side and 90% DBBM and 10% PAB (90:10) on the other side were conducted in all patients. Cone beam computed tomography (CBCT) was obtained preoperatively, immediately postoperative, and after 10 months of healing. Width and volumetric changes in the alveolar process were measured on CBCT. Implants were placed after 10 months of graft healing where biopsies were obtained for histomorphometrical evaluation. Results: The gained widths were 4.9 (±2.4) mm (100:0) and 4.5 (±2.0) mm (90:10) at 3 mm from the top of the crest, and 5.6 (±1.3) mm (100:0) and 4.6 (±2.1) mm (90:10) at 6 mm from the top of the crest. The mean volumetric reductions were 32.8% (±23.8) (100:0) and 38.2% (±23.2) (90:10). Histomorphometry revealed that mean percentages of bone were 50.8% (±10.7) (100:0) and 46.4% (±11.3) (90:10), DBBM were 31.6% (±12.6) (100:0) and 35.4% (±14.8) (90:10), and non‐mineralized tissue were 17.6% (±11.7; 100:0) and 18.2% (±18.2) (90:10). No significant differences were evident between in any evaluated parameters. Conclusions: There were no additional effects of adding PAB to DBBM regarding bone formation, width changes, or volumetric changes after 10 months of graft healing. [ABSTRACT FROM AUTHOR]

Introduction: The radiographic examination of alveolar bone using 3D radiographic examination is essential in dental implant treatment planning. Our study aimed to systematically review and quantitatively analyze the correlation between alveolar bone parameters, specifically bone density and cortical bone thickness, assessed using cone beam computed tomography (CBCT) and/or multidetector computed tomography (MDCT); and primary implant stability (PIS) determined using implant stability quotient (ISQ), Periotest® value (PTV), and insertion torque value (ITV). Methods: This review was registered in the PROSPERO database (registration number CRD42022307245). An electronic literature search was conducted on the PubMed, SCOPUS, and Web of Science databases for papers published until February 2022. The Quality Assessment in Prognostic Studies (QUIPS) tool was used to assess risk of bias. Meta‐analyses were conducted to calculate the estimated average correlation coefficient based on a multilevel random‐effects model, followed by subgroup analysis. Results: Twenty‐six studies were included in this review, consisting of 17 prospective cohort studies, eight retrospective cohort studies, and one nonrandomized controlled trial. A total of 3109 implants placed in 1171 subjects were analyzed. Twenty‐three studies were evaluated using meta‐analysis. The alveolar bone condition was significantly correlated with ISQ (r = 0.60; p <.001), IT (r = 0.52; p <.001), and PTV (r = −0.42; p <.05). Conclusion: Alveolar bone condition is significantly associated with PIS. Low bone density and thin cortical bone can lead to low PIS; therefore, modification of treatment planning and surgical procedures might be needed to avoid poor osseointegration. [ABSTRACT FROM AUTHOR]

Objectives: To compare implant placement accuracy and patient‐centered results between the dynamic computer‐assisted implant surgeries (d‐CAISs) using marker‐based and marker‐free registration methods. Materials and Methods: A double‐armed, single‐blinded randomized controlled trial was conducted, in which 34 patients requiring single implant placement at the esthetic zone were randomly assigned to the marker‐based (n = 17) or marker‐free (n = 17) groups. The marker‐based registration was performed using a splint containing radiopaque markers, while the marker‐free registration used natural teeth. The primary outcome assessed implant positioning accuracy via angular and linear deviations between preoperative and postoperative implant positions in CBCT. Patients were also surveyed about the intraoperative experience and oral health impact profile (OHIP). Results: The global linear deviations at the implant platform (0.82 ± 0.28 and 0.85 ± 0.41 mm) and apex (1.28 ± 0.34 and 0.85 (IQR: 0.64–1.50) mm) for the marker‐based and marker‐free groups respectively showed no significant difference. However, the angular deviation of the marker‐free group (2.77 ± 0.92°) was significantly lower than the marker‐based group (4.28 ± 1.58°). There was no significant difference in the mean postoperative OHIP scores between the two groups (p =.758), with scores of 2.74 ± 1.21 for marker‐based and 2.93 ± 2.18 for marker‐free groups, indicating mild oral health‐related impairment in both. Notably, patients in the marker‐free group showed significantly higher satisfaction (p =.031) with the treatment procedures. Conclusions: D‐CAIS with a marker‐free registration method for single implantation in the anterior maxilla has advantages in improving implant placement accuracy and patients' satisfaction, without generating a significant increase in clinical time and expenses. [ABSTRACT FROM AUTHOR]

Objectives: To radiographically evaluate the stability of the bone substitute augmented outside the buccal bony arch contour in the maxillary esthetic zone. Materials and Methods: Patients who missed a single anterior tooth and received simultaneous GBR in implant surgery were included. The contralateral homonymous area of the implant site was horizontally mirrored as the individual bone arch contour. According to the relative position of the postoperative buccal grafts and bone arch contour at the implant shoulder, 62 patients were allocated into the outside‐contour (OC) and inside‐contour (IC) groups. Cone‐beam computed tomography was performed before surgery, after implant insertion, before re‐entry surgery, and at follow‐up. The profilometric changes of the buccal bone plate were analyzed via the bone distance to the mirrored bony contour. Results: At the implant shoulder, the bone distance in the OC group was higher than that in the IC group, with statistically significant differences at re‐entry surgery and follow‐up. However, the bone grafts outside the bone arch contour were reduced into the contour after remodeling and showed more bone resorption than the IC group. At other vertical levels below the implant shoulder, bony grafting of overcontour 1–2 mm range was favorable to regenerate stable bone plates reaching the individual contour at follow‐up. Conclusions: The overaugmented bone outside the buccal bone arch contour tended to remodel into the original contour, which indicates that the anterior bone arch contour is worthy of careful observation for deciding buccolingual implant position and bone augmentation width. [ABSTRACT FROM AUTHOR]

Objectives: This study evaluated the accuracy of dental implant placement using the robotic computer‐assisted implant surgery (r‐CAIS) technology in fully edentulous patients. Materials and Methods: Fully edentulous and terminal dentition patients were enrolled for r‐CAIS technology. Based on the cone‐beam computed tomography (CBCT) examination, a customized positioning marker and a preoperative surgical plan were created before surgery. During the implant surgery, the implant osteotomy and placement were automatically performed using an autonomous robotic surgery system under the surgeon's supervision. A postoperative CBCT scan was used to determine the discrepancies between the planned and placed implants. Results: Ten patients with 59 implants underwent autonomous robotic surgery. No adverse surgical events occurred. The deviations of global coronal, global apical, and angular were 0.67 ± 0.37 mm (95% CI: 0.58–0.77 mm), 0.69 ± 0.37 mm (95% CI: 0.59–0.78 mm), and 1.27° ± 0.59° (95% CI: 1.42°–1.11°), respectively. Conclusions: The autonomous r‐CAIS technology proved an accurate surgical approach for implant placement in fully edentulous patients due to the control of the angular deviation. Autonomous robotic surgery seems promising as an accurate technology for treating fully edentulous patients. However, further trials are required to provide more hard clinical evidence. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate the possible interference of image artifacts (IA) generated by dental implants in the evaluation of furcation involvement (FI) in molars. Methods: Tomographic scans of first molars (1M) were performed in dry skulls in the absence and presence of titanium (TI) and zirconia (ZI) dental implants. FI grades were simulated in the alveoli of the 1Ms. Diagnostic accuracy of FI and level of difficulty were verified. Chi‐squared test and logistic regression analysis were used. Results: There was no difference in the diagnostic accuracy of FI between the arches (p =.117). The highest diagnostic accuracy value for the implant variable was found in the absence of implants (88.3%) and the lowest in the presence of two ZI implants (66.7%). The highest diagnostic accuracy value for FI was observed in grade 0 (G0). There was no significant difference between the arches regarding the evaluators' perception of difficulty (p >.05). Assessments were considered difficult in 12.7% of the TI implants and in 29% of the ZI implants. Regarding the number of dental implants, assessments were considered difficult in 24.4% cases including one implant and 17.4% cases including two implants. The logistic regression model showed a significant p‐value only for one and two ZI implants (p =.0061 and p =.0096, respectively). Conclusion: The presence of dental implants in the region adjacent to the area of investigation of FI decreased the diagnostic accuracy while increasing the perception of difficulty by the examiners, especially in cases with ZI implants. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the influence of metal artefact reduction (MAR) in the diagnosis of dental implant contact with the mandibular canal (MC) using cone beam computed tomography (CBCT). Methods: Dental implants were installed with surgical guides in the posterior hemiarches of 10 dry human mandibles: 0.5 mm above to the MC cortex (G1/n = 8) and 0.5 mm inside the MC (G2/n = 10). The experimental set‐up was scanned with two CBCT equipment using 85 kV and 90 kV, MAR ON or OFF, and different tube currents (4 mA, 8 mA and 10 mA). Two dentomaxillofacial radiologists (DMFRs) and two dentists (DDS) scored the relation between the dental implant and MC. Descriptive statistics were used to observe the absolute frequency of scores. Sensitivity, specificity and accuracy were calculated considering the known relation between the dental implant and the MC interior. McNemar's test (α =.05) was applied to compare the diagnostic efficacy of MAR ON versus MAR OFF. Results: Overall specificity was higher than sensitivity for both DDS and DMFR (97% vs. 50% and 92.0% vs. 78.0% respectively). There was a significant effect of MAR (p =.031) for DMFR in the case of contact between the dental implant with the MC interior, in which sensitivity decreased with MAR activation from 90% to 40%. DMFR observers showed a better diagnostic performance compared with the DDS observers (accuracy of 84.0% and 71.0%, respectively). Conclusions: Due to the limited efficacy of MAR, it should not be used when conducting CBCT scans for the evaluation of contact between the implant and the mandibular canal. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to evaluate the effect of aging on the changes in implant stability over time following implant placement. Materials and methods: A total of 104 patients in four age ranges (group 1: <60 years, group 2: 61–70 years, group 3: 71–80 years, and group 4: >80 years) were included. Bone‐level tapered implants were placed without implementing any bone augmentation procedure. The final torque value displayed on the implant engine during implant insertion was recorded. Cone‐beam computed tomography (CBCT) was performed immediately after surgery to analyze the bone quality around the implant. Implant stability was measured immediately after surgery and 2, 4, and 8 weeks after surgery. Results: In the CBCT image, higher grayscale values were observed in the order of group 1, group 2, and groups 3/4, with statistical significance (p <.05). There was no significant difference in the insertion torque values between age groups (p ≥.05). Groups 1 and 2 showed lower implant stability values after 2 and 4 weeks compared to immediately and 8 weeks after surgery (p <.05); however, groups 3 and 4 showed no significant difference between the results measured at different timepoints (p ≥.05). Conclusions: Implant treatment in elderly patients is successful showing a settled implant stability over time following implant placement when the implant is appropriately engaged in the alveolar bone in the absence of bone augmentation. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the associations between the cortical bone‐to‐implant contact (CBIC), bone microstructure derived from cone‐beam computed tomography (CBCT), and the primary stability of the implant. Materials and Methods: Twenty‐two patients with 65 implants were enrolled in this study. The peak insertion torque values (ITVs) were measured during implant insertion, and the implant stability quotient (ISQ) values were measured immediately after implant placement and 3 months after surgery. The profiles of the peri‐implant bone structure were outlined using the volumetric reconstruction of the CBCTs and superimposition of the virtual models, and the features of CBIC and bone microstructure parameters were measured. The linear mixed effects model and generalized estimating equation were used to explore the predictors for implant primary stability. Results: The average ITV, baseline, and secondary ISQ values were 31.44 ± 6.54 N·cm, 73.34 ± 7.39, and 80.32 ± 4.58, respectively. Statistically significant correlations were found between ITV and surface area of CBIC (r =.340, p =.006), bone volume fraction (r =.294, p =.017), and bone surface fraction (r = −.278, p =.039). Implants with buccolingual CBIC had a higher ITV than implants without CBIC (p =.016). None of the parameters were associated with baseline and secondary ISQ values in generalized estimating equation analysis (all p >.05). Conclusions: Within the limitations of the study, preoperative CBCT measurements might enable the prediction of ITV and therefore of implant primary stability values. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the accuracy of a miniaturized dynamic navigation system with intraoral markers and two different workflows for dental implantation and to compare with static computer‐assisted implant surgery (sCAIS) surgery. Materials and Methods: Two operators performed a total of 270 implant insertions in polyurethane mandibular models under simulated clinical conditions. Implants were placed after CBCT‐based virtual planning in three different groups: two workflows utilizing dynamic computer‐assisted implant surgery (dCAIS; DG1: marker in CBCT; DG2: 3D‐printed marker) and the others with sCAIS (TG: template guided). Postoperative surface scans were matched to the planning data and allowed an evaluation of the angular and spatial deviation between the planned and the actually achieved implant position. Descriptive statistics were followed by a Mixed Model Analysis to determine the influence of the operator, the method, and operating area on different accuracy parameters and the random effect of the model number. Results: The mean angular deviation ranged from 2.26° (DG1) to 2.96° (TG). The mean 3D deviation at the implant's tip ranged from 1.08 mm (TG) to 1.51 mm (DG2) and at the implant's base from 0.69 mm (TG) to 1.49 mm (DG2). The operator showed no significant influence on the accuracy. The method showed significant influence on singular parameters and the operating area on all spatial accuracy parameters. Conclusions: Dynamic navigation systems with intraoral markers enable accurate implant positioning, which is comparable to the static‐guided implant surgery. 3D‐printed markers provide less accurate results compared to prefabricated markers, attached before CBCT scan. [ABSTRACT FROM AUTHOR]

Objectives: The objective of the study was to evaluate the radiographic changes in sinus mucosal thickness (SMT) in patients with mucosal thickening of odontogenic origin after maxillary molar extraction and lateral sinus augmentation with simultaneous surgical drainage and implant placement. Materials and Methods: Forty‐six patients were included in this study. The changes in SMT were evaluated using cone‐beam computed tomography images produced at four time points: before extraction (T0), before surgery (T1), immediately after surgery (T2), and after prosthesis delivery (T3), and statistical differences between time points were analyzed. The changes in SMT and augmented bone height (ABH) regarding the reason of extraction, smoking, ostial patency, and the presence of postoperative sinusitis were also evaluated. Results: Over time points, SMT gradually decreased (T0: 19.44 ± 9.22 mm, T1: 15.10 ± 8.89 mm, T2: 8.42 ± 6.01 mm, and T3: 4.16 ± 4.91 mm) (p <.05). Five out of 6 patients with ostial obstruction at T1 presented ostial patency at T3. Two patients developed postoperative sinusitis but recovered with medication. Ostial patency at T1, SMT at T1, and reason of extraction did not statistically significantly influence SMT at T3. SMT at T1 had no statistically significant impact on ABH change between T2 and T3. Conclusion: Sinus mucosal thickness was gradually reduced by extraction of compromised teeth and drainage during lateral sinus augmentation. The drainage contributed more to the reduction in SMT. [ABSTRACT FROM AUTHOR]

Objectives: Registration of intra‐oral surface scans to cone beam computer tomography (CBCT) is critical in the digital workflow for static computer‐aided implant surgery (sCAIS). This study aimed to assess the impact of CBCT field of view (FoV) on the precision of digital intra‐oral scan registration. Materials and Methods: Cone beam computer tomography data and intra‐oral scans from 20 patients were included. Small FoV CBCT's were created by digitally segmenting a large FoV into three sextants. Virtual implant planning was performed. Digital intra‐oral scans were repeatedly registered onto their corresponding large and small FoV CBCT datasets. The distances and angulations between the matching implant positions of each repeated registration were used to determine the precision of the registration process. Wilcoxon Signed Rank Paired Tests were used to compare the differences between large FoV and small FoV. The threshold for statistical significance was set at p =.05. Results: Differences in 3D implant position based on the registration precision between small FoV and large FoV present at both the implant entry point (0.37 ± 0.25 mm vs 0.35 ± 0.23 mm, p =.482) and implant tip (0.49 ± 0.34 mm vs 0.37 ± 0.24 mm, p <.001). Differences in overall angular precision were observed between small FOV and large FoV (1.43 ± 1.36° vs 0.51 ± 0.38°, p <.001). Conclusion: CBCT with a small FoV is accompanied by greater precision errors in intra‐oral scan registration. However, when sufficient well‐distributed teeth are visible in small FoV CBCT, the precision of digital intra‐oral scan registration appears to be within clinically acceptable limits for sCAIS. [ABSTRACT FROM AUTHOR]

Aim: To assess, in vitro, variables potentially influencing implant blooming using a human‐like imaging phantom and 3D‐printed mandibles. Material and Methods: Sixty implants were inserted in 3D‐printed mandibles in 26 different configurations in order to examine the impact of implant diameter, presence of a cover screw, implant design/material, implant position, and the presence of additional implants on implant blooming using two cone‐beam computed tomography (CBCT) devices (Accuitomo [ACC] and NewTom [NWT]). Two observers measured the amount of implant blooming in both buccolingual and mesiodistal directions. Inter‐rater agreement and descriptive statistics, grouped by implant characteristic and CBCT device, were calculated. Results: Both CBCT devices increased implant diameter (a mean increase of 9.2% and 11.8% for titanium, 20.3% and 24.4% for zirconium, for ACC and NWT, respectively). An increase in implant diameter did not increase the amount of blooming, whereas placing a cover screw did (from 8.0% to 10.9% for ACC, and from 10.0% to 15.6% for NWT). Moreover, implant design, anatomical region, and the presence of another implant also affected the extent of the blooming. Conclusions: Dental implants show a clear diameter increase on CBCT, with the effect being more pronounced for zirconium than for titanium implants. Similar effects are likely to occur in the clinical setting, potentially masking nonosseointegration, reducing the dimensions of peri‐implant defects, and/or causing underestimation of the buccal bone thickness. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the impact of reducing the radiographic field of view (FOV) on the trueness and precision of the alignment between cone beam computed tomography (CBCT) and intraoral scanning data for implant planning. Materials and Methods: Fifteen participants presenting with one of three clinical scenarios: single tooth loss (ST, n = 5), multiple missing teeth (MT, n = 5) and presence of radiographic artifacts (AR, n = 5) were included. CBCT volumes covering the full arch (FA) were reduced to the quadrant (Q) or the adjacent tooth/teeth (A). Two operators, an expert (exp) in virtual implant planning and an inexperienced clinician, performed multiple superimpositions, with FA‐exp serving as a reference. The deviations were calculated at the implant apex and shoulder levels. Thereafter, linear mixed models were adapted to investigate the influence of FOV on discrepancies. Results: Evaluation of trueness compared to FA‐exp resulted in the largest mean (AR‐A: 0.10 ± 0.33 mm) and single maximum discrepancy (AR‐Q: 1.44 mm) in the presence of artifacts. Furthermore, for the ST group, the largest mean error (−0.06 ± 0.2 mm, shoulder) was calculated with the FA‐FOV, while for MT, with the intermediate volume (−0.07 ± 0.24 mm, Q). In terms of precision, the mean SD intervals were ≤0.25 mm (A‐exp). Precision was influenced by FOV volume (FA < Q < A) but not by operator expertise. Conclusions: For single posterior missing teeth, an extended FOV does not improve registration accuracy. However, in the presence of artifacts or multiple missing posterior teeth, caution is recommended when reducing FOV. [ABSTRACT FROM AUTHOR]

Objectives: To retrospectively evaluate whether repositioning the bone window leads to a better outcome of three‐dimensional sinus augmentation in lateral sinus floor elevation (LSFE) with simultaneous implant placement. Methods: 34 patients with a total of 40 implants (14: test group, 26: control group) receiving LSFE with simultaneous implant placement were included in this retrospective research. CBCT images were taken before surgery, immediately and 6 months after surgery. The two‐dimensional augmentation parameters, including apical bone height (ABH), endo‐sinus bone gain (ESBG), and palatal/buccal bone height (PBH/BBH), and three‐dimensional parameters, including augmentation volume (AV) and palatal/buccal augmentation volume (PAV/BAV), were measured. The lateral defect length (LDL) and lateral window length (LWL) were also measured to evaluate the lateral antrostomy recovery. Results: At the 6‐month follow‐up, the reduction rates at ABH, ESBG, and BBH of the test group (ABH: 10.41% ± 30.30%, ESBG: 2.55% ± 8.91%, BBH: 2.50% ± 8.65%) were significantly lower than those of the control group (ABH: 25.10% ± 22.02%, ESBG: 11.47% ± 9.79%, BBH: 7.10% ± 5.37%; p <.05). In addition, the test group showed better three‐dimensional augmentation stability on the buccal side (BAV reduction: 15.51% ± 10.86% vs. 27.15% ± 12.61%; p <.05). Moreover, the LDL/LWL ratio of the test group was significantly lower than that of the control group (p <.05). Conclusion: Within the limitations of this study, repositioning of the bone window in LSFE with simultaneous implant placement could contribute to endo‐sinus augmentation stability on the buccal side at the 6‐month follow‐up. Moreover, it would also facilitate recovery of the lateral antrostomy defect. [ABSTRACT FROM AUTHOR]

Aim: To validate in vitro the accuracy of a novel method for bone augmentation of horizontal alveolar bone defects with the help of a surgical guide. Material and methods: Six cone‐beam computed tomography scans of patients requiring horizontal bone augmentation were segmented and 3D printed. Two surgeons performed the bone augmentation surgery twice for each case on 3D‐printed models, using either a conventional or guided protocol. Each surgeon virtually planned the desired graft shape beforehand. The resulting grafts were compared linearly and volumetrically to the plan; graft density and surgical time were also analyzed. Results: There was significantly less graft volume outside the planned volume with the guided protocol (36.8% ± 14.1 vs. 19.6% ± 12.3, p <.01). The use of a guide increased graft accuracy at several measurement points, resulting in less overfill when using the guided protocol (1.7 ± 1.7 mm at the most coronal point, 0.2 mm ± 1.4 at 25%, 0.0 mm ± 0.9 at 50%, 0.1 mm ± 1.1 at 75%, and 0.4 mm ± 1.4 apically). Graft thickness was increased 1 mm coronally from the planned graft (2.8 mm ± 2.3 vs. 1.8 mm ± 2.2, p =.04). Surgical time increased significantly when using a guide (a difference of 2 m 26 s). Conclusion: The technique, tested here in vitro, allows surgeons to improve the accuracy of the resulting graft shape, to better compact material in the coronal portion of the graft, and to reduce the amount of graft material placed outside the planned volume. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to determine whether distally angulating an implant is a successful strategy to avoid the maxillary sinus and the need for bone augmentation, while increasing the anterior‐posterior (A‐P) implant distribution in the edentulous maxilla. Materials and Methods: In 115 patients with edentulous maxillae, virtual implant planning was performed utilizing cone‐beam computer tomographs. Axial (8 mm length) and tilted (12 mm length) dental implants with 30‐degree and 45‐degree angulation were virtually positioned to avoid entering the maxillary sinus, while maximizing A‐P distribution. Measurements were made between the tilted and axial implants to assess the change in A‐P distribution of implants at the implant and abutment levels. Results: Forty‐seven sites (20.4%) were not able to have either treatment modality with insufficient bone for implant placement. Axial implants were placed more distally than 45‐degree and 30‐degree tilted implants in 24% and 42% of sites, respectively. The average change in A‐P spread measured at the implant level, for 30‐ and 45‐degree tilted implants was −0.25 mm (95% CI −0.76, 0.26) and 1.9 mm (95% CI 1.4, 2.3), respectively. When measured from the center of each multi‐unit abutment the average increase in A‐P distances for tilted implants appears larger in the 30‐degree and 45‐degree groups by 0.97 mm and 1.74 mm, respectively compared to measurements at the implant level. Conclusions: Angulating 12 mm implants provides a limited increase in A‐P distribution of implants in edentulous rehabilitation in most situations. In certain patients, the use of 8mm axial implants may provide a greater A‐P spread. [ABSTRACT FROM AUTHOR]

Objectives: This randomized controlled trial aimed to compare crestal bone loss (CBL) and buccal bone thickness (BBT) around triangular cross‐section neck (TN) to round neck (RN) implants retaining mandibular overdentures one year after loading, using cone beam computed tomography (CBCT). Material and Methods: Twenty edentulous patients receiving 40 implants with similar diameters were randomly assigned to the RN and TN groups. Clinical buccal bone thickness (CBBT) around the implants was measured with a caliper at baseline. A resonance frequency analyzer was used to measure the implant stability quotient (ISQ) at the baseline and two months after insertion. Pocket probing depths (PPD), plaque index (PI), and gingival index (GI) were also recorded at postoperative months 2, 6, and 12. CBCT was used to evaluate proximal CBL and BBT at three levels (0, −2, and −4 mm) one year after loading. Results: No implant loss was observed during the follow‐up period. No significant differences in CBBT, ISQ values, and scores for PPD, PI, and GI between the two groups were observed at any time (p >.05). BBT was also comparable one year after loading (p >.05). The mean ± SD proximal CBL one year after loading was 0.58 ± 0.36 mm for TN and 0.91 ± 0.59 mm for RN (p <.01). Conclusions: This study found better crestal bone preservation in the implants with the novel neck design than conventional neck design in the anterior mandible after a follow‐up of one year. However, it may not be clinically noticeable. [ABSTRACT FROM AUTHOR]

Objectives: To measure in vivo 3D accuracy of backward‐planned partially guided implant surgery (PGIS) based on dental magnetic resonance imaging (dMRI). Material and Methods: Thirty‐four patients underwent dMRI examinations. Tooth‐supported templates were backward planned using standard dental software, 3D‐printed, and placed intraorally during a cone beam computed tomography (CBCT) scan. Treatment plans were verified for surgical viability in CBCT, and implants were placed with guiding of the pilot drill. High‐precision impressions were taken after healing. The 3D accuracy of 41 implants was evaluated by comparing the virtually planned and definitive implant positions with respect to implant entry point, apex, and axis. Deviations from the dMRI‐based implant plans were compared with the maximum deviations calculated for a typical single implant. Results: Twenty‐eight implants were placed as planned in dMRI. Evaluation of 3D accuracy revealed mean deviations (99% confidence intervals) of 1.7 ± 0.9mm (1.2–2.1mm) / 2.3 ± 1.1mm (1.8–2.9 mm) / 7.1 ± 4.8° (4.6–9.6°) for entry point / apex / axis. The maximum deviations calculated for the typical single implant surpassed the upper bounds of the 99% CIs for the apex and axis, but not for the entry point. In the 13 other implants, dMRI‐based implant plans were optimized after CBCT. Here, deviations between the initial dMRI plan and definitive implant position were only in part higher than in the unaltered group (1.9 ± 1.7 mm [0.5–3.4 mm] / 2.5 ± 1.5 mm [1.2–3.8 mm] / 6.8 ± 3.8° [3.6–10.1°] for entry point / apex / axis). Conclusions: The 3D accuracy of dMRI‐based PGIS was lower than that previously reported for CBCT‐based PGIS. Nonetheless, the values seem promising to facilitate backward planning without ionizing radiation. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the present study was to explore the feasibility of ultrasonography (US) for clinical imaging of peri‐implant tissues. Material and Methods: Patients with ≥1 implant, a cone‐beam computed tomography (CBCT) scan, an US scan, and clinical photographs taken during the surgery were included. The crestal bone thickness (CBT) and facial bone level (FBL) were measured on both US and CBCT modalities, and direct FBL measurements were also made on clinical images. US measurements were compared with CBCT and direct readings. Results: A total of eight implants from four patients were included. For FBL measurements, US and direct (r2 = 0.95) as well as US and CBCT (r2 = 0.85) were highly correlated, whereas CBCT correlated satisfactorily with the direct reading (r2 = 0.75). In one implant without facial bone, CBCT was not able to measure CBT and FBL accurately. The estimated bias for CBT readings was 0.17 ± 0.23 mm (p =.10) between US and CBCT. US blood flow imaging was successfully recorded and showed a wide dynamic range among patients with different degrees of clinical inflammation. Conclusion: US is a feasible method to evaluate peri‐implant facial crestal bone dimensions. Additional US features, for example, functional blood flow imaging, may be useful to estimate the extent and severity of inflammation. [ABSTRACT FROM AUTHOR]

Objectives: To radiographically evaluate the effect of the adjunctive use of tenting screws (TS) for primary horizontal guided bone regeneration (GBR). Materials & Methods: Twenty‐eight patients in need of staged bone augmentation were consecutively treated in a private practice. A xenogenic particulate bone substitute material (DBBM) and a resorbable collagen membrane were used in all patients. Subjects were divided into two groups: control (conventional GBR; n = 22) and test (tenting screws in conjunction with GBR ‐ TS; n = 22). CBCT images were obtained before augmentation and after 6–8 months. CBCTs were superimposed, and linear horizontal measurements were performed. Alveolar ridge width (RW) and ridge width change (RWchange) were assessed at 1, 3, 5, and 7 mm below the bone crest. Results: Forty‐four sites in 28 patients were evaluated. No differences between the groups were detected for RW at baseline (TS: 5.87 ± 2.41; control: 5.36 ± 1.65). Regarding RWchange, TS promoted an additional effect at 1 and 3 mm below the crest compared to control (p <.05; RWchange‐1 TS: 3.72 ± 2.46; control: 1.25 ± 3.05; RWchange‐3 TS: 3.98 ± 2.53; control: 2.50 ± 2.02). The final RW was greater in group TS compared to the control group at the 1, 3, and 5 mm level (p <.05). Conclusions: The use of tenting screws exerted a positive effect on staged GBR with a greater final RW at the 3 mm level. In addition, GBR in conjunction with TS was able to provide consistent bone augmentation at lingual/palatal sites. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the diagnostic accuracy of cone beam computed tomography (CBCT) for the diagnosis of peri‐implant bone defects of titanium (Ti), zirconium dioxide (ZrO2) or titanium–zirconium (Ti–Zr) alloy implants. Materials and Methods: Ti, Ti–Zr or ZrO2 implants with two diameters (3.3 mm, 4.1 mm) and one length (10 mm) were inserted in the angle of the mandible of six fresh defrosted pig jaws. Out of the 12 implants inserted, 6 served in the test group with standardized buccal peri‐implant bone defects, whereas 6 served as control without bone defects. CBCTs were performed with three acquisition protocols (standard, high and low dose) using two devices. Four observers analysed CBCTs as follows: (a) presence of a peri‐implant defect; (b) presence of peri‐implant artefacts and impact on defect diagnosis; and (c) linear measurements of buccal peri‐implant defect including height and width (in mm). Results: CBCT device, CBCT settings, implant material, implant diameter and observer background did not significantly influence diagnostic accuracy. The sensitivity and specificity values were high for defect detection. ZrO2 led to a lower than average diagnostic accuracy (0.781). The linear measurements of peri‐implant defect were underestimated by <1 mm on average. The subjective impact of artefacts on defect diagnosis was significantly affected by implant material and observer background. Conclusions: CBCT showed high diagnostic accuracy for peri‐implant bone defect detection regardless of the device, imaging setting or implant material used. If CBCT is indicated to assess peri‐implant bone disease, low dose protocols could be a promising imaging modality. [ABSTRACT FROM AUTHOR]

Objectives: To compare ear, nose, and throat (ENT) specialists and dentists assessing health or pathology of maxillary sinuses using cone beam computed tomography (CBCT). Material and methods: Two ENT specialists and two oral surgeons assessed 100 CBCT datasets of healthy patients referred for dental implant placement in the posterior maxilla and decided on the possibility of sinus floor elevation or the necessity for further diagnostic examinations based solely on radiographic findings. Inter‐rater agreements within the same specialty were calculated with Cohen's kappa and overall agreements with Fleiss kappa, and factors influencing the decisions taken were evaluated using regression analyses. Results: The correlation between all four raters was generally fair to moderate. The intra‐specialty comparison showed a lower correlation between dentists than between ENT specialists. Absence of membrane thickening and total or subtotal sinus opacification showed the highest predictive value for a consensus in favor of sinus floor elevation and ENT referral, respectively. Flat membrane thickening with an irregular surface morphology was associated with disagreement between the examiners. Dome‐shaped membrane thickenings were often considered as to be referred by dentists but not by ENTs. Conclusion: The assessment of maxillary sinuses using CBCT imaging exhibited unsatisfactory agreement between ENT specialists and oral surgeons. Referral guidelines based on accidental CBCT findings that aim to diagnose relevant sinus pathologies early and avoid unnecessary diagnostics and/or therapies are needed, and an initial proposal for such recommendations is provided. Further research on correct interpretation of sinus findings and a validation of the present recommendations are required. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this split‐mouth randomized controlled clinical trial was to compare the deviations of planned and placed implants placed by the assistance of a micron tracker‐based dynamic navigation device or freehand methods. Material and methods: A thermoplastic fiducial marker was adapted on the anterior teeth, and cone‐beam computerized tomography was used for imaging. A minimum of one implant was planned for each side of the posterior maxilla, and the dynamic navigation device or freehand method was randomly used for surgical insertion. Deviations were measured by matching the planning data with a final CBCT image. Linear deviations (mm) between the planned and placed implants were the primary outcome. The results were analysed by generalized linear mixed models (p <.05). (NCT03471208). Results: A total of 92 implants were placed to 32 volunteers, and 86 implants were included in the final analysis. For the linear deviations, mean of differences (Δ) was 0.72mm (Standard deviation (SD): 0.26); (95% Confidence interval (CI): 0.39–1.02) in the shoulder of the implants (p <.001) and 0.69mm (SD: 0.36); (95% CI: 0.19–1.19) in the tip of the implants (p <.001). For the angular deviations, Δ was 5.33° (SD: 1.63); (95% CI: 7.17–3.48); (p <.001). Conclusions: The navigation technique can be used to transfer virtual implant planning to the patient's jaw with increased accuracy. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the in vitro diagnostic accuracy of low‐dose cone‐beam computed tomography (LD‐CBCT) for the detection, classification, and measurement of peri‐implant bone lesions. Material and methods: Titanium dental implants with all‐ceramic single crowns (n = 24) were inserted into bovine bone. At twelve implants, four types of peri‐implant bone lesions were created. Radiographic imaging was performed using three techniques: LD‐CBCT, high‐definition CBCT (HD‐CBCT), and intraoral radiography (IR). The datasets were presented twice to four observers in a random order. Diagnostic accuracy was measured by calculating sensitivity and specificity, and analyzed using the McNemar's test at a significance level of 0.05. Absolute agreement between the defect sizes was assessed by means of intraclass correlation coefficients (ICC). Results: For all three techniques, diagnostic accuracy and reliability for the detection of defects were almost perfect. The following order was found for classification of the different defect types (sensitivity/specificity): HD‐CBCT (0.96/0.99) > LD‐CBCT (0.93/0.98) > IR (0.71/0.95). No significant difference was found between the two CBCT techniques. Their performance was superior to that of IR. With regard to absolute agreement of defect size, LD‐CBCT agreement with HD‐CBCT (ICC, 95% confidence interval) was slight for defect depth (0.342, 0.181–0.625) and substantial for defect width (0.911, 0.775–0.963). Conclusion: Intraoral radiography is useful for detecting peri‐implant bone lesions. LD‐CBCT provides additional information regarding the geometry of defects. The even higher diagnostic accuracy of the HD‐CBCT protocol tested needs to be carefully weighed against its radiation dose, which is 14 times higher than that of LD‐CBCT. [ABSTRACT FROM AUTHOR]

Objectives: To assess through cone‐beam computed tomography (CBCT) buccal alveolar bone alterations after immediate implant placement using the following techniques: open flap and grafting (flap‐graft), open flap and no grafting (flap‐nograft) and flapless and no grafting (noflap‐nograft). Materials and methods: This was a three‐armed parallel group randomized clinical trial with allocation ratio 1:1:1. Patients were eligible in case they needed immediate implant replacing teeth in maxillary premolar area, with sufficient buccal bone support. CBCT was performed immediately after the intervention and 6 months later. The main outcomes were CBCT measurements performed at apical (A‐EA), medial (M‐EM) and external and internal implant bevel level (B‐EB, B‐IB) and vertical defect depth (DP). Pain and discomfort, time of surgery and complications were recorded. Differences between groups were estimated through ANOVA tests and post‐hoc Scheffe's analysis for pairwise comparisons. Multiple regressions were conducted to estimate influence of gingival biotype and baseline marginal gap dimension. Results: Forty‐five patients were recruited and randomized to treatments with one lost to follow‐up. Analysis of variance showed that the effect of treatment technique was not relevant for all horizontal and vertical outcomes. The three techniques exhibited almost complete fill of marginal gap, with a mean residual vertical gap of 0.27 mm and horizontal gap of 0.5 mm. Regression models indicated a positive effect of thick biotype on gap filling and dimensional bone reduction. The noflap‐nograft technique resulted less painful. Conclusions: The option of noflap‐nograft surgery in post‐extraction implants allows for minimal surgical intervention with comparable buccal bone changes and gap filling after a follow‐up of 6 months in sites with sufficient buccal bone support. [ABSTRACT FROM AUTHOR]

Objectives: To test whether block bone substitute used for guided bone regeneration (GBR) of peri‐implant defects leads to different thickness of the augmented hard tissue than particulate bone substitute. Material and methods: In 24 patients, 24 two‐piece dental implants were placed >4 months after tooth extraction. Following random allocation, 12 peri‐implant bone dehiscences were grafted with an individually shaped block of deproteinized bovine‐derived bone mineral (DBBM) and 12 bone dehiscences with particulate DBBM. All the sites were covered with a collagen membrane stabilized with resorbable pins. Immediately after wound closure and after 6 months, the horizontal thickness (HT) of the augmented hard tissue was measured at the level of implant shoulder using ‐computed tomography. Results: After wound closure, the median HT measured 3.35 mm (mean: 3.38) in the block group and 2.85 mm (mean: 2.73) in the particulate group. At 6 months, the median HT decreased to 2.90 mm (mean: 2.71) in the block group and to 0.2 mm (mean: 0.52) in the particulate group. This difference was statistically significant (p < .001). Conclusions: Block bone substitute used for GBR of peri‐implant defects was superior to particulate bone substitute regarding the dimension of the augmented hard tissue after 6 months of healing. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this prospective cohort study was to evaluate computer‐guided implant surgery with tooth‐supported drill guides based on CBCT scans and intraoral scanning. Materials and methods: For partially edentulous patients, a prosthetic and surgical planning was completed in the guided surgery software (coDiagnostiX) and drill guides were 3D‐printed accordingly. Three months after implant placement, an intraoral scan of the implant's position was used to evaluate the accuracy of placement using the coDiagnostiX treatment evaluation tool. Deviations were reported in degrees and in distance at implant's entry point and apex. Several risk factors, which might influence the accuracy, were evaluated separately: treated jaw, flap design, prior augmentations, amount of unrestored teeth, crowding, location of implants, cortical interference, and implant's length and diameter. Results: A total of 66 patients received 145 Straumann tissue level implants that were eligible for accuracy analysis. The mean angular deviation was 2.72° ± 1.42. The mean three‐dimensional deviation at the implant's entry point was 0.75 mm ± 0.34. At implant's apex, the mean was 1.06 mm ± 0.44. The amount of unrestored teeth (p = .002 & p = .003), the implant's location (p < .001), the implant's length (p = .004), and cortical interference (p = .033) had a significant influence on the accuracy of placement. Implant survival was 99.3% (n = 1 failed implant) at 12 and 24 months. Conclusions: Guided surgery with tooth‐supported drill guides made in a digital workflow is a feasible treatment option. However, deviations do occur and the implant's length, location, cortical interference and the amount of unrestored teeth have a significant influence on the accuracy. [ABSTRACT FROM AUTHOR]

Objectives: Guided implant surgery (GIS) requires alignment of virtual models to reconstructions of three‐dimensional imaging. Accurate visualization of the tooth surfaces in the imaging datasets is mandatory. In this prospective clinical study, in vivo tooth surface accuracy was determined for GIS using cone‐beam computed tomography (CBCT) and dental magnetic resonance imaging (dMRI). Materials and methods: CBCT and 3‐Tesla dMRI were performed in 22 consecutive patients (mean age: 54.4 ± 15.2 years; mean number of restorations per jaw: 6.7 ± 2.7). Altogether, 92 teeth were included (31 incisor, 29 canines, 20 premolars, and 12 molars). Surfaces were reconstructed semi‐automatically and registered to a reference standard (3D scans of stone models made from full‐arch polyether impressions). Reliability of both methods was assessed using intraclass correlation coefficients. Accuracy was evaluated using the two one‐sided tests procedure with a predefined equivalence margin of ±0.2 mm root mean square (RMS). Results: Inter‐ and intrarater reliability of tooth surface reconstruction were comparable for CBCT and dMRI. Geometric deviations were 0.102 ± 0.042 mm RMS for CBCT and 0.261 ± 0.08 mm RMS for dMRI. For a predefined equivalence margin, CBCT and dMRI were statistically equivalent. CBCT, however, was significantly more accurate (p ≤ .0001). For both imaging techniques, accuracy did not differ substantially between different tooth types. Conclusion: Cone‐beam computed tomography is an accurate and reliable imaging technique for tooth surfaces in vivo, even in the presence of metal artifacts. In comparison, dMRI in vivo accuracy is lower. Still, it allows for tooth surface reconstruction in satisfactory detail and within acceptable acquisition times. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the accuracy of a prosthetic treatment plan incorporation into a cone beam computed tomography (CBCT) scan using point‐based registration with three registration points selected and to evaluate the impact of number of registration points on prosthetic plan accuracy. Material and Methods: A CBCT scan of a completely dentate master model with removable teeth was exposed after removing the mandibular left first premolar, second premolar, and first molar. A digital scan of the master model with all teeth present was made by scanning a stone replica using a laboratory scanner. The digital model was registered onto the three‐dimensional (3D) volume rendering of the CBCT scan using implant planning software. The point‐based registration was repeated using three, four, five, six, seven, eight, nine, and 10 reference points. Metrology software was used to measure the 3D deviation of the registered models for each reference point group on standard tessellation language (STL) files obtained from the CBCT scans. An STL file of the master model with all teeth present obtained from another CBCT scan was used as reference. Results: Using three registration points, the registered prosthetic plan had a mean absolute deviation of 17.63 µm from the reference. Increasing the number of registration points failed to demonstrate statistically significant effects on the deviation (p > 0.05). Conclusions: For this clinical scenario, three registration points provided adequate accuracy for prosthetic plan incorporation into CBCT scans. Increasing the number of registration points had no significant impact on the prosthetic plan accuracy in this study. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the accuracy of implant placement with a digitally planned guided implant procedure. Two methods for identifying the actual postoperative positioning of the implants were compared: CBCT and IO scanning. Material and methods: Twenty‐eight implants with a sandblasted and acid‐etched surface were placed in thirteen patients using tooth‐supported surgical guides following a digital planning procedure. The implants were submerged for 12–15 weeks. New CBCT images were taken for identification of the implant position. After second stage surgery, scan bodies were mounted on the implants and scanned with an IO digital scanner. The recordings from the CBCT images and the IO scans were compared with respect to the identified positions of the implants. Results: The study did not resolve any significant differences of the identified positioning of the implants as measured by CBCT or IO, except for the apical deviations at the coronal and apical points. The angular difference between CBCT and IO scanning at the coronal point was −0.011 (±0.6) degrees, whereas the 3D deviation was 0.03(±0.17) mm. The distal deviation between CBCT and IO scanning was 0.01(± 0.16) mm, and the vestibular deviation 0.033(± 0.16) mm and the apical deviation difference was 0.09(± 0.16) mm. The 3D deviation at the apical point was 0.04(± 0.22) mm. The distal deviation between CBCT and IO scanning was 0.06(± 0.19) mm, and the vestibular deviation 0.032(± 0.23) mm and the apical deviation difference was 0.09(± 0. 16) mm. Conclusion: The study demonstrated that accuracy measurements using IO scanning yields comparable results to those obtained by CBCT. [ABSTRACT FROM AUTHOR]

Objectives: To compare the trueness of 3D digital models derived from CBCT and IOS and to evaluate their accuracy for implementation in oral implant rehabilitation. Materials and methods: A dry human mandible with a full set of intact teeth was included in the study. The mandible was scanned using Trios IOS and four different CBCT machines with various protocols for generation of 3D digital models. A µCT was utilized to scan each tooth individually. Following registration and segmentation, the trueness evaluation of 3D digital models was carried out by part comparison analysis and color‐coded mapping of the superimposed teeth surfaces. Results: The four CBCT‐derived 3D digital models with different protocols had better trueness than Trios IOS. NewTom VGi evo (110 KV), ProMax 3D (90 kV), 3D Accuitomo 170 (90 kV), Green 21 (110 kV), and Green 21 (90 kV) showed significantly better trueness than IOS. However, 3D Accuitomo 170 and ProMax 3D CBCT devices with 70 kV protocol showed better trueness without any significant difference with IOS. Conclusion: CBCT‐derived 3D digital models showed better trueness when compared with IOS. When CBCT data are available for preoperative planning for oral implant rehabilitation, it may preclude the need for IOS for obtaining 3D study models. [ABSTRACT FROM AUTHOR]

Objective: Slit‐window technique is a lateral approach sinus floor elevation (SFE) procedure that utilizes a rigid resorbable membrane in conjunction with stabilizing bony slits to tent the Schneiderian membrane without addition of grafting materials. The aim of this randomized clinical trial was to compare clinical and radiographic outcomes of the Slit‐window SFE with those of SFE with bone grafting. Material and Methods: Thirty‐three patients with 38 edentulous sites were included. Edentulous sites were randomly allocated to the Slit‐window SFE or SFE with bone grafting. Simultaneous with SFE, each site received two dental implants. Implant stability quotient (ISQ) values were recorded at baseline and monthly visits for 8 months. The bone coverage and bone height gain at implant sites were recorded on cone beam computed tomography (CBCT) scans 6 and 24 months postoperatively. Results: There were no significant differences in the mean ISQ values between the groups at any time point (p > 0.05). All implants in both groups were found to have complete bone coverage. Significant increases in the bone height were found 6 and 24 months postoperatively in both groups (p < 0.001). Conclusions: Within limitations of the present study, it can be concluded that the Slit‐window SFE technique without the need for bone grafting resulted in sufficient bone height gain around implants placed simultaneous with the SFE procedures. The bone height around these implants was stable during the 2‐year follow‐up period. The treatment outcomes for these implants were comparable to those placed simultaneous with lateral approach SFE in conjunction with bone grafting. [ABSTRACT FROM AUTHOR]

Objectives: Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer‐aided implant surgery (s‐CAIS) and patient‐related outcome measurements when using s‐CAIS were addressed. Materials and methods: The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted. Results: Static computer‐aided surgery (s‐CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s‐CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent. Conclusions: Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s‐CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s‐CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care. [ABSTRACT FROM AUTHOR]

Objective: The aim of this systematic review was to identify, review, analyze, and summarize available evidence on the accuracy of linear measurements when using maxillofacial cone beam computed tomography (CBCT) specifically in the field of implant dentistry. Material and methods: The search was undertaken in April 2017 in the National Library of Medicine database (Medline) through its online site (PubMed), followed by searches in the Cochrane, EMBASE, ScienceDirect, and ProQuest Dissertation and Thesis databases. The main inclusion criterion for studies was that linear CBCT measurements were performed for quantitative assessment (e.g., height, width) of the alveolar bone at edentulous sites or measuring distances from anatomical structures related to implant dentistry. The studies should compare these values to clinical data (humans) or ex vivo and/or experimental (animal) findings from a "gold standard." Results: The initial search yielded 2,516 titles. In total, 22 studies were included in the final analysis. Of those, two were clinical and 20 ex vivo investigations. The major findings of the review indicate that CBCT provides cross‐sectional images that demonstrate high accuracy and reliability for bony linear measurements on cross‐sectional images related to implant treatment. A wide range of error has been reported when performing linear measurements on CBCT images, with both over‐ and underestimation of dimensions in comparison with a gold standard. A voxel size of 0.3 to 0.4 mm is adequate to provide CBCT images of acceptable diagnostic quality for implant treatment planning. Conclusions: CBCT can be considered as an appropriate diagnostic tool for 3D preoperative planning. Nevertheless, a 2 mm safety margin to adjacent anatomic structures should be considered when using CBCT. In clinical practice, the measurement accuracy and reliability of linear measurements on CBCT images are most likely reduced through factors such as patient motion, metallic artefacts, device‐specific exposure parameters, the software used, and manual vs. automated procedures. [ABSTRACT FROM AUTHOR]

Objectives: Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer‐aided implant surgery (s‐CAIS) and patient‐related outcome measurements when using s‐CAIS were addressed. Materials and methods: The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted. Results: Static computer‐aided surgery (s‐CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s‐CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent. Conclusions: Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s‐CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s‐CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care. [ABSTRACT FROM AUTHOR]

Objective: The aim of this systematic review was to identify, review, analyze, and summarize available evidence on the accuracy of linear measurements when using maxillofacial cone beam computed tomography (CBCT) specifically in the field of implant dentistry. Material and methods: The search was undertaken in April 2017 in the National Library of Medicine database (Medline) through its online site (PubMed), followed by searches in the Cochrane, EMBASE, ScienceDirect, and ProQuest Dissertation and Thesis databases. The main inclusion criterion for studies was that linear CBCT measurements were performed for quantitative assessment (e.g., height, width) of the alveolar bone at edentulous sites or measuring distances from anatomical structures related to implant dentistry. The studies should compare these values to clinical data (humans) or ex vivo and/or experimental (animal) findings from a "gold standard." Results: The initial search yielded 2,516 titles. In total, 22 studies were included in the final analysis. Of those, two were clinical and 20 ex vivo investigations. The major findings of the review indicate that CBCT provides cross‐sectional images that demonstrate high accuracy and reliability for bony linear measurements on cross‐sectional images related to implant treatment. A wide range of error has been reported when performing linear measurements on CBCT images, with both over‐ and underestimation of dimensions in comparison with a gold standard. A voxel size of 0.3 to 0.4 mm is adequate to provide CBCT images of acceptable diagnostic quality for implant treatment planning. Conclusions: CBCT can be considered as an appropriate diagnostic tool for 3D preoperative planning. Nevertheless, a 2 mm safety margin to adjacent anatomic structures should be considered when using CBCT. In clinical practice, the measurement accuracy and reliability of linear measurements on CBCT images are most likely reduced through factors such as patient motion, metallic artefacts, device‐specific exposure parameters, the software used, and manual vs. automated procedures. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The aim of this study was to compare bone block grafts fixed at a distance (BBG‐D) with the SonicWeld Rx shell technique (Poly‐D‐L‐Lactide foil fixed at a distance, augmented with autogenous and deproteinized bovine bone particles (SWST)) for lateral alveolar ridge augmentation. Methods: In this single‐blinded, randomized, controlled trial, 30 patients with a bucco‐palatal bone width of ≤3 mm were randomized into the treatment groups: “BBG‐D” and “SWST”. Bone width was measured with cone beam computed tomography (CBCT). One implant was placed at each grafted site. Frequencies of complications, bone gain and bone resorption in the CBCT were assessed as outcomes. Results: Fifteen sites were augmented in each treatment group. One graft (7%) in the BBG‐D group and five (33%) in the SWST group were lost (p = 0.17). In the SWST group, two implants (20%) were lost and none in the BBG‐D group (p = 0.18). The rate of pooled severe complications (loss of graft and/or implant) was different (p = 0.035). Five (33%) wound dehiscences happened in the SWST group and none in the BBG‐D group (p = 0.042). Seven (47%) nonsevere complications (wound dehiscence, inflammation, transient nerve injury) happened in the SWST group and one (7%) in the BBG‐D group (p = 0.035). At the one‐year evaluation, there were no significant differences in bone loss at the mesial, distal or buccal implant shoulder between treatment groups. Conclusions: Within the limitations of this study, the BBG‐D method remains the gold standard for lateral alveolar ridge augmentation compared to the shell technique because of the lower complication rates. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this retrospective study was to evaluate the long‐term changes in the thickness of Schneiderian membranes after zygomatic implant placement using cone beam computed tomography (CBCT). Material and methods: Twenty‐five consecutive patients were included in this study. All the patients underwent bilateral zygomatic implant placement. Schneiderian membrane thickness (SMT) in 49 maxillary sinuses (one sinus was not included because of early loss of the zygomatic implants) was measured using CBCT before and at least 1 year after zygomatic implant placement. Ostium patency of each sinus was also evaluated and recorded. Results: In total, 84 zygomatic implants and 30 regular implants were placed in included patients. Two unilateral maxillary zygomatic implants in one patient were removed 2 months after implant placement. The SMT increased from 1.03 mm (inter‐quartile range: 1.57 mm) to 1.33 mm (inter‐quartile range: 1.98 mm) after a median follow‐up time of 23.00 months (inter‐quartile range: 14 months), and the difference was statistically significant. Before zygomatic implant insertion, 24.5% (12/49) of sinuses had SMT greater than 2 mm, whereas this value was 28.6% (14/49) after zygomatic implant placement. The percentage of sinuses observed with ostium patency also increased from 2.0% (1/49) to 12.2% (6/49). Conclusions: Chronic Schneiderian membrane thickening could result from zygomatic implant insertion. Intensive postoperative care and clinical and radiographic monitoring are recommended after zygomatic implant placement. [ABSTRACT FROM AUTHOR]

Abstract: Aim: The aim of this split‐mouth randomized controlled study was to evaluate radiographic dimensional changes after tooth extraction in posterior sites treated with a ridge preservation technique or left for spontaneous healing. Materials and Methods: In a total of 18 patients, tooth extraction in posterior sites of the upper and lower jaw was performed in a split‐mouth design. The post‐extraction sockets were randomly assigned to the following two treatment modalities: deproteinized bovine bone mineral (DBBM) with 10% collagen (DBBM‐C) covered with a native bilayer collagen membrane (NBCM) (test group) and spontaneous healing (control group). Cone beam computed tomography (CBCT) scans were performed after extractions, 3 and 6 months later. The following parameters were measured: the height of the buccal bone plate (BH), height of the palatal bone plate (PH), horizontal width of the extraction socket at 1 mm, 3 mm, and 5 mm (HW‐1, HW‐3, HW‐5), and the horizontal width (thickness) of the buccal bone plate at 1 mm, 3 mm, and 5 mm (BHP‐1, BHP‐3, BHP‐5). Statistical analysis was performed applying a nonparametric Wilcoxon signed‐rank test. Results: The CBCT analysis showed a bone loss compared to baseline in test and control group. The measurements which have reached statistically significant differences at 6 months were BH (test: −2.31% vs control: −13.11%), PH (test: −2.07% vs control: −15.32%), HW‐1 (test: −17.14% vs control: −32.47%), and HW‐3 (test: −11.65% vs control: −28.47%). Conclusions: The posterior ridge preservation technique using DBBM‐C covered with a NBCM is a valid approach reducing the amount of the radiographic loss in alveolar ridge dimensions. [ABSTRACT FROM AUTHOR]