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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]

Objectives: To investigate the dimensional changes following the extraction of maxillary second incisors and to evaluate the influence of deproteinised bovine bone mineral on the healing outcomes. Materials and Methods: The second maxillary incisors in nine dogs were extracted bilaterally in a minimally traumatic manner. Deproteinised bovine bone mineral with collagen (DBBMC) and a collagen matrix (CM) was placed in one socket with the contralateral socket left to heal naturally. After 3 months of healing, the dogs were sacrificed and the pre‐maxilla resected. Cone beam computerised tomography scans (CBCTs) were obtained and the specimens prepared for histological preparation and analysis. Surface scans of study models taken pre‐ and post‐extraction were digitally subtracted to analyse volumetric changes. Results: All dogs healed uneventfully without any complications. No inflammation was seen, and DBBMC was well integrated into a network of mineralised tissues, bone marrow and connective tissue. The horizontal width of the buccal crest was found to be significantly greater in grafted sockets, but the vertical height to be similar. No significant difference was seen in regard to volumetric changes in sockets over 3 months post‐extraction. Conclusion: Maxillary second incisor sockets of dogs grafted with DBBMC post‐extraction had significantly greater horizontal width at the ridge crest compared with ungrafted sockets. Volumetric analysis revealed no significant difference between grafted and non‐grafted sockets, suggesting possible soft tissue thickening post‐extraction to counteract osseous resorption. [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]

Objectives: To test whether or not alveolar ridge preservation reduces vertical changes in the posterior maxilla compared to spontaneous healing following tooth extraction. Materials and methods: Forty subjects requiring extraction of maxillary posterior teeth with root apices protruding into the maxillary sinus floor were consecutively enrolled. Patients were randomly assigned to either one of two surgical interventions: an alveolar ridge preservation procedure using collagenated bovine bone mineral and a resorbable collagen membrane (test) or no grafting (control). Cone‐beam computed tomographies were taken immediately and at 6 months after surgery, prior to dental implant placement. Results: Based on radiographic data, the level of the sinus floor remained stable over time (baseline to 6 months) in the test group (−0.14 mm [−0.31, −0.02]). In the control group, the sinus floor level shifted more coronally (−1.16 mm [−1.73, −0.61]) than the test group (p < 0.05). The test group demonstrated a significantly larger residual bone height than the control group at 6 months (7.30 mm [6.36, 8.20] vs. 4.83 mm [3.94, 5.76], respectively, p < 0.05). Implant placement without any additional sinus augmentation procedure was performed in 42.9% of test group cases, whereas in all of the subjects in the control group an additional augmentation procedure was needed (100% of the cases). Conclusion: Alveolar ridge preservation in the posterior maxilla maintained the vertical bone height more efficiently and resulted in less need for sinus augmentation procedures at 6 months compared to spontaneous healing. [ABSTRACT FROM AUTHOR]

Objective: To use cone beam computed tomography (CBCT) to assess the alterations of socket dimensions after a 6‐month healing period following molar extraction. Materials and methods: Seventeen molars were extracted due to advanced periodontitis. CBCT scans were taken immediately after extraction and once more 6 months later. Superimposition of CBCT images was used to measure the following: horizontal changes at extraction sites at three corono‐apical levels (−1, −3, and −5 mm) below the bone crest, three mesio‐distal levels (mesial, central, and distal), vertical changes at nine regions of the alveolar crest, and alveolar bone volume. Results: The width of the central crests at −1 mm decreased by 0.59 and 0.72 mm in the buccal and 0.27 and 0.02 mm in the lingual, in the maxilla and mandible, respectively. No statistically significant decreases in the ridge height were observed except in the disto‐palatal region with a 1.11 mm decrease in the maxilla (p < 0.05). Heights of the buccal and lingual bone plates decreased significantly and ranged from 0.56 to 1.38 mm in the mandible after 6 months of healing (p < 0.05). Overall, ridge height changes were not significantly different between the maxilla and mandible (p > 0.05) and no significant volumetric bone loss occurred in either maxillary or mandibular sockets after 6 months of healing. Conclusions: Socket dimensions of molars with advanced periodontal disease showed a significant increase at the middle‐central portion, although there were no significant changes of horizontal width 6 months following the procedures. [ABSTRACT FROM AUTHOR]

Objectives: The aims of this study were to (a) present a novel morphological contour interpolation (MCI) algorithm based method to evaluate grafted bone alterations following guided bone regeneration (GBR), (b) compare clinical and radiological outcomes of GBR with two different collagen membranes. Materials and methods: The data were retrieved from an ongoing randomized controlled trial. Patients were randomly allocated into two groups: (a) control group (CG): Bio‐Gide (b) test group (TG): bovine dermis‐derived collagen membrane. Cone beam computed tomography examinations were performed 1 week (T0) and 6 months after surgery (T1). PES/WES at T1, grafted bone volume and density changes from T0 to T1 were recorded. Results: Thirty‐six patients (16/20 in test/control group, respectively) were enrolled in the present study. Excellent inter‐observer reliability (ICC ≥ 0.97) was revealed for repeated measurements using this method. Significant volumetric reduction of grafted bone were found in both groups (test group: from 0.60 to 0.39 cm3, p < 0.01; control group: from 0.54 to 0.31 cm3, p < 0.01). Mean bone density (gray‐scale values) significantly increased from 305.12 to 456.69 in CG (p < 0.01). In TG, it slightly increased from 304.75 to 393.27 (p = 0.25). The mean PES/WES values were 13.84 (6.62/7.22) and 13.90 (6.70/7.20) for TG and CG, respectively. As for inter‐group comparison, no significant differences of grafted bone volume change, density change and PES/WES were found between two groups. Conclusion: Within the limitations of this study, the novel MCI‐based method is a reproducible tool to segment and visualize changes of grafted bone in 3D. Furthermore, both collagen membranes could be used as a barrier membrane for GBR in humans. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the volumetric changes following lateral alveolar ridge augmentation using autogenous bone graft covered by either a platelet‐rich fibrin membrane (test group) or an inorganic bovine bone substitute and a resorbable collagen barrier membrane (control group). Material and methods: A total of 27 partially edentulous patients (test n = 14, control n = 13) with the indication for lateral bone block augmentation were included in this randomized, controlled clinical trial. Cone beam computed tomography (CBCT) examination was performed prior to grafting and 2 weeks and 6 months after grafting. The volumetric changes between the various examinations times were evaluated by planimetric measurements on two‐dimensional CBCT images of the grafted regions. Results: The mean bone volumetric loss in the test group was 14.7%, SD ±8.9%, while the mean bone volume loss in the control group was 17.8%, SD ±13.3%. This difference was not significant (p = 0.48). A total of ten patients were operated in the incisor and canine region with a mean bone volume loss of 23.41% SD, ±10.87%, while 17 patients were operated in the premolar region with a mean bone volume loss of 11.89% SD ±9.05%. This difference was significant (p = 0.01). Conclusion: The test and control group demonstrated no overall difference in volumetric bone changes of the augmented bone at the 6‐month follow‐up. The second major finding revealed a significantly larger amount of bone resorption in the incisor and canine region than in the premolar region of the maxilla, particularly in the control group. [ABSTRACT FROM AUTHOR]

Objective: To test the accuracy of measurement of interproximal peri‐implant bone defects at titanium (Ti) and zirconium dioxide (ZrO2) implants by digital periapical radiography (PR) and cone beam computed tomography (CBCT). Material and methods: A total of 18 models, each containing one Ti and one ZrO2 implant, were cast in dental stone. Six models each were allocated to following defect groups: A—no peri‐implant defect, B—1 mm width defect, C—1.5 mm width defect. The defect width was measured with a digital sliding caliper. Subsequently, the models were scanned by means of PR and CBCT. Three examiners assessed the defect width on PR and CBCT. Wilcoxon signed‐rank test and Wilcoxon rank sum test were applied to detect differences between imaging techniques and implant types. Results: For PR, the deviation of the defect width measurement (mm) for groups A, B, and C amounted to 0.01 ± 0.03, −0.02 ± 0.06, and −0.00 ± 0.04 at Ti and 0.05 ± 0.02, 0.01 ± 0.03, and 0.09 ± 0.03 at ZrO2 implants. The corresponding values (mm) for CBCT reached 0.10 ± 0.11, 0.26 ± 0.05, and 0.24 ± 0.08 at Ti and 1.07 ± 0.06, 0.64 ± 0.37, and 0.54 ± 0.17 at ZrO2 implants. Except for Ti with defect A, measurements in PR were significantly more accurate in comparison to CBCT (p ≤ 0.05). Both methods generally yielded more accurate measurements for Ti than for ZrO2. Conclusions: The assessment of interproximal peri‐implant defect width at Ti and ZrO2 implants was more accurate in PR in comparison to CBCT. Measurements in CBCT always led to an overestimation of the defect width, reaching clinical relevance for ZrO2 implants. [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: 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. [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]

Abstract: Objective: The aim of this multicenter prospective study was to analyze clinically and histologically the influence of sinus cavity dimensions on new bone formation after transcrestal sinus floor elevation (tSFE). Material and Methods: Patients needing maxillary sinus augmentation (residual crest height <5 mm) were treated with tSFE using xenogeneic granules. Six months later, bone‐core biopsies were retrieved for histological analysis in implant insertion sites. Bucco‐palatal sinus width (SW) and contact between graft and bone walls (WGC) were evaluated on cone beam computed tomography, and correlations between histomorphometric and anatomical parameters were quantified by means of forward multiple linear regression analysis. Results: Fifty consecutive patients were enrolled and underwent tSFE procedures, and forty‐four were included in the final analysis. Mean percentage of newly formed bone (NFB) at 6 months was 21.2 ± 16.9%. Multivariate analysis showed a strong negative correlation between SW and NFB (R2 = .793) and a strong positive correlation between WGC and NFB (R2 = .781). Furthermore, when SW was stratified into three groups (<12 mm, 12 to 15 mm, and >15 mm), NFB percentages (36%, 13% and 3%, respectively) resulted significantly different. Conclusions: This study represented the first confirmation based on histomorphometric data that NFB after tSFE was strongly influenced by sinus width and occurred consistently only in narrow sinus cavities (SW <12 mm, measured between buccal and palatal walls at 10‐mm level, comprising the residual alveolar crest). [ABSTRACT FROM AUTHOR]

Abstract: Objective: To evaluate the use of a synthetic bone substitute covered with a collagen membrane for ridge preservation after tooth extraction, by clinical and tomographic analysis. Material and Methods: Fifteen patients, presenting at least two maxillary anterior teeth indicated for extraction, were selected: in the test group (TG), post‐extraction sockets were filled by a synthetic bone substitute; in the control group (CG), by blood clot. In both groups, the sockets were covered by a collagen membrane. Cone‐beam computerized tomography (CBCT) scans were acquired immediately after and 6 months post‐surgically, and horizontal and vertical dimensional bone changes were quantified. Results: Transurgical clinical analysis presented no statistically significant differences between TG and CG (p > .05). CBCT intragroup evaluation presented statistically significant reduction for the buccal alveolar measurement (TG = 1.58 mm or 21.82%, and CG = 1.66 mm or 24.08%) and horizontal cervical measurement (TG = 0.55 mm or 8.30% and CG = 1.30 mm or 17.68%), and not significant for palatal alveolar measurement (TG = 0.44 mm or 3.42% and CG = 0.26 mm or 3.89%). For alveolar height and horizontal apical measurements, this decrease was significant only for the CG, with reductions of 1.03 mm and 0.50 mm, respectively, compared to a decrease of 0.57 mm and 0.19 mm for the TG. The intergroup analysis showed significant difference for cervical horizontal measurement after 6 months (p < .05). Conclusion: The results showed that the use of the bone substitute covered with a collagen membrane resulted in less changes in vertical and horizontal alveolar ridge dimensions than the collagen membrane alone. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to analyze linear and volumetric hard tissue changes in severely resorbed alveolar sockets after ridge augmentation procedure and to compare them with spontaneous healing using three‐dimensional cone beam computed tomography (CBCT). Material and methods: Thirty patients (mean age 53.2 ± 6.3 years) requiring tooth extraction for advanced periodontitis were randomly allocated to test and control groups. The test sites were grafted using a collagenated bovine‐derived bone (DBBM‐C) covered with a collagen membrane, while control sites had spontaneous healing. Both groups healed by secondary intention. Linear and volumetric measurements were taken on superimposed CBCT images obtained after tooth extraction and 12 months later. Results: Greater horizontal shrinkage, localized mainly in the crestal zone, was observed in the control group (4.92 ± 2.45 mm) compared to the test group (2.60 ± 1.24 mm). While both groups presented a rebuilding of the buccal wall, it was most pronounced in the grafted sockets (2.50 ± 2.12 mm vs. 0.51 ± 1.02 mm). A significant difference was also registered in the percentage of volume loss between grafted and non‐grafted sites (9.14% vs. 35.16%, p‐value <.0001). Conclusion: Alveolar sockets with extensive buccal bone deficiencies undergo significant three‐dimensional volumetric alterations following natural healing. The immediate application of a slow‐resorbing xenograft with a covering collagen membrane seems to be effective in improving alveolar ridge shape and dimensions, thus potentially reducing the need for adjunctive regenerative procedures at the time of implant placement. [ABSTRACT FROM AUTHOR]

Purpose The aim of this study was to radiographically compare horizontal and vertical alterations of the alveolar ridge after ridge preservation using different combinations of biomaterials. Materials and methods The patients were randomly assigned into two groups: (a) the test group, which received collagenated porcine bone plus cross-linked collagen membrane (n = 15), and (b) the control group, which received collagenated bovine bone plus non-cross-linked collagen membrane (n = 15). Cone beam computed tomography ( CBCT) was performed immediately after ridge preservation and 4 months thereafter to compare the horizontal and vertical alterations of the ridge. Intention-to-treat ( ITT) and per protocol ( PP) analyses were performed. Results In both analyses, there was no statistically significant difference in the horizontal alteration of the alveolar ridge between the test and control groups: −1.3 ± 0.6 ( ITT)/1.2 ± 0.5 ( PP) vs. −1.5 ± 0.9 mm at the 1-mm level; −1.2 ± 0.7 ( ITT and PP) vs. −1.2 ± 0.7 mm at the 3-mm level; and −0.9 ± 0.7 ( ITT)/ −0.9 ± 0.7 ( PP) vs. −0.9 ± 0.9 mm at the 5-mm level, whereas the vertical height in the midfacial area was significantly reduced in the test group compared with the control group: −-1.1 ± 2.8 ( ITT)/1.5 ± 3.0 ( PP) vs. −0.7 ± 1.8 mm. Conclusions The horizontal ridge alteration in ridge preservation did not differ significantly between using the test the control groups, but the vertical ridge alteration was more pronounced when using the test group ( KCT0001709). [ABSTRACT FROM AUTHOR]

Objective To objectively compare the influence of different cone-beam computed tomography (CBCT) devices, high-density materials and field of views ( FOVs) on metal artifact expression. Material and methods For this in vitro study, three customized acrylic resin phantoms containing high-density materials cylinders: titanium, copper-aluminum alloy and amalgam were scanned on three CBCT devices using high-resolution protocols, same voxel size (0.2 mm) and different FOVs. After fully automatic segmentation and image registration, the same region of interest was defined for the small and medium FOVs. The difference between the segmented and the real volume of the metal cylinders was assessed. Moreover for each segmented slice, the area difference between the segmented and the real axial section was determined. The artifacts on the background were measured as normalizing standard deviation of voxel values in the vicinity of the cylinder, in three different distances. Results Considerable differences were observed in volume measurements for all CBCTs devices and materials for both FOV sizes (up to 67%). The slice per slice area analysis indicated higher artifacts at the edges of the metal cylinder. Within the materials, amalgam and titanium had, respectively, the worst and best artifact expression in all the CBCT devices. Standard deviation values varied differently between the three distances in each device. Conclusion Our in vitro study showed that different CBCT devices, high-density materials and FOV should be considered while evaluating CBCT images. More carefully, diagnosis conclusions should be drawn in images containing amalgam and copper-aluminum alloy. [ABSTRACT FROM AUTHOR]

Aim To test whether an equine bone substitute block used for guided bone regeneration ( GBR) of peri-implant defects differs from bovine block or particulate bone substitutes regarding the hard and soft tissue contours of the augmented ridge. Material & Methods Two semi-saddle bone defects were prepared in each side of the mandible of eight dogs, and one titanium implant was inserted into every defect. The defects were randomly allocated to receive one of the following treatments: bone augmentation by GBR using (1) particulate deproteinized bovine bone mineral ( DBBM) + a collagen membrane ( CM), (2) block DBBM + CM, (3) equine bone substitute block + CM, and (4) empty controls. After 4 months, the jaws were scanned by means of cone beam computed tomography ( CBCT). CBCT analysis was performed in one central and two lateral (mesial and distal) regions of interest ( ROI) of each site evaluating the horizontal thickness of the augmented hard tissue ( HThard tisue) and the total thickness of hard and soft tissue ( HTtotal). The Wilcoxon-Pratt signed rank test was used for statistical analysis. Results In the majority of ROIs, equine and bovine blocks rendered significantly higher values in HThard tissue and HTtotal than controls ( P < 0.05). Generally, equine blocks reached the highest values in HThard tissue and HTtotal followed by DBBM blocks and particulate DBBM. The differences in HThard tissue and HTtotal between GBR groups were not statistically significant ( P > 0.05). In the central ROI, HThard tissue at the level of the implant shoulder measured 1.7 ± 1.4 mm for equine blocks, 1.7 ± 1.0 mm for DBBM blocks, 0.9 ± 1.2 mm for particulate DBBM, and 0 ± 0 mm for controls. The corresponding values in the lateral ROI reached 1.9 ± 1.1 mm for equine blocks, 1.2 ± 0.8 mm for DBBM blocks, 1.0 ± 0.9 mm for particulate DBBM, and 0 ± 0 mm for controls. Conclusions GBR with bone substitute blocks lead to higher ridge dimensions than empty controls. The equine block with CM rendered the most favorable outcomes in hard and soft tissue contours followed by DBBM block and DBBM granulate with CM. [ABSTRACT FROM AUTHOR]

Objectives This randomized clinical trial analyzed crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the mandible anterior region at different depths (equicrestal and subcrestal). Materials and methods Eleven edentulous patients (five implants per patient) were randomly divided in a split-mouth design: G1, 28 equicrestal implants; and G2, 27 subcrestal implants. All implants were immediately loaded. Correlation between keratinized tissue width ( KTW) and vertical mucosa thickness ( MT) with soft tissue recession was analyzed. Intraoral radiographs were used to evaluate crestal bone changes. Patients were assessed immediately, 4-, and 8-months after implant placement. Rank-based ANOVA-type statistical test was used for comparison between groups (α = 0.05). Results Fifty-five implants (G1 = 28 and G2 = 27) were assessed in 11 patients. Implant survival rate was 100% for both groups. Both tested implant placement depths presented similar crestal bone loss ( P > 0.05). Significant crestal bone loss for each group was found in the different measurement times (T4 and T8) ( P < 0.05). Implant placement depths, KTW, and vertical MT had no effect on soft tissue recession ( P > 0.05). Conclusions Different implant placement depths do not influence crestal bone changes. Soft tissue behavior is not influenced by different implant placement depths or by the amount of keratinized tissue. [ABSTRACT FROM AUTHOR]

Objectives To radiographically investigate early outcomes of osteotome sinus floor elevation in the healing phase utilizing cone beam computed tomography and evaluate influences of Schneiderian membrane conditions. Material and methods One hundred patients were consecutively recruited for osteotome sinus floor elevation ( OSFE) surgery using deproteinized bone mineral. CBCT was taken prior to ( T0), immediately post-operatively ( T1), and after the healing period ( T2). Linear and volumetric measurements of the elevated region from T0 to T1 were performed for evaluation on computed tomography ( CT). Results Osteotome sinus floor elevation were performed in 100 patients. One implant of each patient was selected. Mean residual bone height ( RH) was 7.21 ± 1.12 mm. Mean sinus floor elevation height ( SE) was 4.81 ± 0.75 mm. The mean endo-sinus bone gain after the healing period was 3.25 ± 0.83 mm. Pre-opterative CBCT scans revealed that 72 patients had a normal sinus membrane in osteotome region, 13 patients presented with flat thickened mucosa and 15 patients with antral pseudocysts. There is no significant difference in sinus mucosa elevation height, bone graft volume and new bone formation in group of Thickening membrane and Antral pseudocysts compared with normal. Conclusions The radiographical results show that OSFE is a safe and predictable surgical procedure in residual bone height of 7.21 ± 1.12 mm. Mild flat thickening (>2 and <5 mm) and antral pseudocysts in a small size without clinical symptoms may not be contraindications to OSFE surgery. [ABSTRACT FROM AUTHOR]

Objectives To evaluate factors with impact on the conspicuity (possibility to detect) of the buccal bone condition around dental implants in cone beam computed tomography ( CBCT) imaging. Material and Methods Titanium (Ti) or zirconia (Zr) implants and abutments were inserted into 40 bone blocks in a way to obtain variable buccal bone thicknesses. Three combinations regarding the implant-abutment metal (TiTi, TiZr, or ZrZr) and the number of implants (one, two, or three) were assessed. Two CBCT units (Scanora 3D - Sc and Cranex 3D - Cr) and two voxel resolutions (0.2 and 0.13 mm) were used. Reconstructed sagittal images (2.0 and 5.0 mm thickness) were evaluated by three examiners, using a dichotomous scale when assessing the condition of the buccal bone around the implants. A multivariate logistic regression was performed using examiners' detection of the buccal bone condition as the dependent variable. Odds ratio ( OR) were calculated separately for each CBCT unit. Results Implant-abutment combination (ZrZr) ( OR Sc = 19.18, OR Cr = 11.89) and number of implants (3) ( OR Sc = 12.10, OR Cr = 4.25) had major impact on buccal bone conspicuity. The thinner the buccal bone, the higher the risk that the condition of the buccal bone could not be detected. The use of lower resolution protocols increased the risk that buccal bone was not properly detected ( OR Sc = 1.46, OR Cr = 2.00). For both CBCT units, increasing the image reconstruction thickness increased the conspicuity of buccal bone ( OR Sc = 0.33, OR Cr = 0.31). Conclusions Buccal bone conspicuity was impaired by a number of factors, the implant-abutment material being the most relevant. Acquisition and reconstruction factors had minor impact on the detection of the buccal bone condition. [ABSTRACT FROM AUTHOR]

Objectives Guided implant surgery ( GIS) is performed with drilling guides that are produced on the virtual tooth model using CAD/ CAM technology. The prerequisite for this workflow is the alignment of patients cone beam computed tomography CBCT and surface scan (registration). Dental restorations may cause deteriorating imaging artifacts in CBCT data, which in turn can have an impact on the registration process. The influence of the user and the preprocessing of data and of image artifacts on the registration accuracy were examined. Material and Methods CBCT data and intraoral surface scans of 36 patients were used for virtual implant planning in coDiagnostiX (Dentalwings, Montreal, Canada). CBCT data were reconstructed to a three-dimensional anatomical model with the default settings provided by the software and also manually by four different examiners. Subsequently, the CBCT and intraoral surface models were registered by each examiner with the help of anatomical landmarks. Patients' data were subdivided into four groups (A-D) according to the number of metallic restorations: A = 0-2 restorations, B = 3-5 restorations, C = 6-8 restorations and D > 8 restorations. After registration, the distances between CBCT and dental surface models were measured. Linear regression models were used to assess the influence of the segmentation, the examiner and to the number of restorations ( P < 0.05). Results The deviations between surface scan and CBCT models accounted to 0.54 mm (mean). The mean deviations were 0.69 mm (max. 24.8 mm) and 0.4 mm (max. 9.1 mm) for default and manual segmentation, respectively. Mean deviations of 0.36 mm (Group A), 0.43 mm (Group B), 0.67 mm (Group C) and 1.01 mm (Group D) were recorded. The segmentation ( P = 0.000), the user ( P = 0.0052) and the number of restorations ( P = 0.0337) had a significant influence on the registration accuracy. Conclusions The deviation between CBCT and surface scan model resulting from inaccurate registration is transferred to the surgical field and results in a deviation between the planned and actual implant position. The registration accuracy in commercial virtual implant planning software is significantly influenced by the preprocessing of imported data, by the user and by the number of restorations resulting in clinically non-acceptable deviations encoded in drilling guides. [ABSTRACT FROM AUTHOR]

Objectives The aims of this randomized clinical trial were to compare the dimensional changes and the histological composition after using deproteinized bovine bone mineral ( DBBM) or deproteinized bovine bone mineral with 10% collagen ( DBBM-C) and a collagen membrane in ridge preservation procedures. Material and methods Patients who required an extraction and a subsequent implant-supported rehabilitation at a non-molar site were recruited. After extraction, a cone beam computed tomography ( CBCT) was performed and sites were randomly treated either with DBBM or DBBM-C plus a collagen membrane. At 5 months, before implant placement, a second CBCT was performed and a biopsy of the area was obtained. A blinded investigator superimposed the CBCTs and performed measurements to determine bone volume changes between the two time points. Additionally, a histomorphometric analysis of the biopsies was performed in a blinded manner. Results Eleven sites belonged to the DBBM group and eleven to the DBBM-C group. All together, a significant reduction in height and width was observed at 5 months of healing, but no statistically significant differences were observed between the DBBM and the DBBM-C group. The histomorphometric analysis revealed a similar composition in terms of newly formed bone, connective tissue and residual graft particles in both groups. Conclusions Deproteinized bovine bone mineral with 10% collagen showed a similar behaviour as DBBM not only in its capacity to minimize ridge contraction but also from a histological point of view. Thus, both graft materials seem to be suitable for ridge preservation procedures. [ABSTRACT FROM AUTHOR]

Objectives: To test whether GBR with an L-shaped soft-block bone substitute and particulate bone substitute differs from GBR with particulate bone substitute as regards the volume stability of the augmented region during flap closure. Materials and methods: Twenty peri-implant box-shaped bone defects were created in 10 pig mandibles. Every bone defect was augmented with each of the following two GBR procedures in turn: control group – particulate xenograft applied buccally + collagen membrane + pins; test group – particulate xenograft applied buccally + L-shaped soft-block xenograft applied buccally and occlusally + collagen membrane + pins. Cone-beam computed tomography scans were obtained before and after wound closure. The horizontal thickness (HT) of the augmented region (bone substitute + membrane) was assessed at the implant shoulder (HT0 mm) and at 1 mm to 5 mm apical to the implant shoulder (HT1 mm-HT5 mm). In the test group, the vertical thickness (VT) and 45° thickness (45-T) of the augmented region were measured from the implant shoulder. The changes in HT during flap suturing were calculated as absolute (mm) and relative values (%). Repeated-measures ANOVAs were used for statistical analysis. Results: The reduction in HT0 mm was 20.5 ± 23.3% (SD) in the control group and 2.4 ± 9.2% (SD) in the test group (P = 0.014). There were no statistically significant differences in changes in HT1–5 mm between the groups (P > 0.05). In the test group, the reduction in VT amounted to 28.0 ± 11.9% (SD) and the reduction in 45-T amounted to 24.8 ± 10.2% (SD) (P < 0.001). Conclusion: The addition of an L-shaped soft-block bone substitute to a particulate xenograft, covered by a collagen membrane and fixed with pins, significantly improved the horizontal volume stability of the augmented region during wound closure. [ABSTRACT FROM AUTHOR]

Objectives: Cone-beam computed tomography (CBCT) has been used in the literature to evaluate Schneiderian membrane thickness (SMT), but its accuracy has never been validated. The primary aim of this study was to compare the SMT measured by CBCT to the gold standard histological assessment. The correlations between SMT and anatomical structures of the maxillary sinus and alveolar bone were also tested. Materials and Methods: Fourteen fresh cadaver heads were used for the study, and 28 sinus lift augmentation procedures were performed to obtain the membrane samples. Samples were fixed in formalin and stained with hematoxylin–eosine and Masson trichrome. Specimens were measured by optic microscope at three points, and a mean was obtained. Anatomical landmarks were used to accurately position the CBCT slice, so the SMT could be measured in predetermined locations. Wilcoxon signed-rank test was used to compare values of histological and CBCT measurements, and Spearman's correlation coefficient was calculated to examine the relationship between thickness and anatomical parameters. Results: A total of 597 histological measurements were performed, and the mean SMT thickness was 0.30 ± 0.17 mm. The mean CBCT membrane thickness was 0.79 ± 0.52 mm. A statistically significant difference from histological and radiological readings was observed (P = 0.000). Interestingly, 87.77% histological measurements had membrane less than 0.5 mm in thickness compared to 26.66% in CBCT assessment. Conclusions: Within the limitation of this study, the median histological Schneiderian membrane thickness was 0.30 mm. Cone-beam computed tomography assessment was 2.6 times higher than the histological examination. [ABSTRACT FROM AUTHOR]

Purpose The aim of the study was to analyze the accuracy of measuring the cortical bone thickness using a combination of low- and high-frequency ultrasound ( US) compared with cone-beam computed tomography ( CBCT) and using stereomicroscopy as reference method. Material and Methods Ten jawbone models were prepared using bovine ribs and porcine gingiva. A dental implant was placed in each model. All models were investigated by US, CBCT, and stereomicroscopy. The cortical bone thickness was measured directly above and 4 mm beside the implant with each method in different slices. Results The median deviation of US measurements compared to the reference method was 0.23 mm. The CBCT method was slightly more accurate (median percent deviation of 9.2%) than the US method (10.3%). However, US measurements directly above the implant were more accurate than CBCT measurements with a median percent deviation of 10.5% for US vs. 11.8% for CBCT. Conclusion Ultrasound showed a high potential to supplement CBCT for measurements of the cortical bone thickness. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to introduce a new concept for computer-assisted template-guided placement of a custom 3D-designed/3D-printed implant with congruent custom 3D-designed/3D-printed surgical tooling and to test the feasibility and accuracy of this method in-vitro. Materials and methods One partially edentulous human mandibular cadaver was scanned with a cone-beam computed tomography ( CBCT) system and intra-oral scan system. The 3D data of this cadaver were imported in specialized software and used to analyse the region of a missing tooth. Based on the functional and anatomical parameters, an individual implant with congruent surgical tooling and surgical guided template was designed and 3D-printed. The guided osteotomy was performed, and the custom implant inserted. To evaluate the planned implant position in comparison with the placed implant position, the mandible with implant was scanned again with the CBCT system and software matching was applied to measure the accuracy of the procedure. Results The angular deflection with the planned implant position was 0.40°. When comparing the 3D positions of the shoulder, there is a deviation of 0.72 mm resulting in an apical deviation of 0.72 mm. Conclusion With the use of currently available technology, it is very well feasible to create in a virtual simulation a custom implant with congruent custom surgical tooling and to transfer this to a clinical setting. However, further research on multiple levels is needed to explore this novel approach. [ABSTRACT FROM AUTHOR]

Purpose Ultrasound imaging has potential to complement radiographic imaging modalities in implant and oral surgery given that it is non-ionizing and provides instantaneous images of anatomical structures. For application in oral and dental imaging, its qualities are dependent on its ability to accurately capture these complex structures. Therefore, the aim of this feasibility study was to investigate ultrasound to image soft tissue, hard tissue surface topography and specific vital structures. Material and methods A clinical ultrasound scanner, paired with two 14- MHz transducers of different sizes (one for extraoral and the other for intraoral scans), was used to scan the following structures on a fresh cadaver: (i) the facial bone surface and soft tissue of maxillary anterior teeth, (ii) the greater palatine foramen; (iii) the mental foramen and (iv) the lingual nerve. Multiple measurements relevant to these structures were made on the ultrasound images and compared to those on cone-beam computed tomography ( CBCT) scans and/or direct measurements. Results Ultrasound imaging could delineate hard tissue surfaces, including enamel, root dentin and bone as well as soft tissue with high resolution (110 μm wavelength). The greater palatine foramen, mental foramen and lingual nerve were clearly shown in ultrasound images. Merging ultrasound and CBCT images demonstrated overall spatial accuracy of ultrasound images, which was corroborated by data gathered from direct measurements. Conclusion For the first time, this study provides proof-of-concept evidence that ultrasound can be a real-time and non-invasive alternative for the evaluation of oral and dental anatomical structures relevant for implant and oral surgery. [ABSTRACT FROM AUTHOR]

Objectives To evaluate the adjustment of structures designed from a digital impression of implants obtained by cone-beam computerized tomography ( CBCT). Materials and methods Thirty implants were placed in five edentulous mandibles of fresh cadaver heads, six per mandible. Special scan bodies were screwed in the implants and a CBCT was taken. DICOM images were converted to STL and digitally processed to obtain a digital model of the implants. A Cr-Co structure was designed and milled for each mandible, and the adjustment was assessed as in a real clinical situation: passivity while screwing, radiographic fitting, optical fitting, and probing. Results Good adjustment was found in three of the structures, and only slight discrepancies were found in the other two. Conclusion Cone-beam computerized tomography might be a valid impression-taking method in full-mouth rehabilitations with implants. Further evaluations are needed with more implant and CBCT systems. The radiation dose might be considered when deciding to use this impression system. The types of patients appropriate for this treatment option should also be determined to fulfill the principles of the ALARA law. [ABSTRACT FROM AUTHOR]

Aim To examine the influence of two different neck designs on facial bone crest dimensions in esthetic single implant sites after a 5-to-9-year follow-up analyzed by cone beam computed tomography ( CBCT). Materials and methods Sixty-one patients with an implant-borne single crown following early implant placement in the esthetic zone were enrolled. The test group consisted of a bone level ( BL) neck design exhibiting a hydrophilic micro-rough surface combined with a platform-switching interface ( PS) ( n = 20). The control group comprised a soft tissue level ( STL) neck design exhibiting a hydrophobic machined surface with a matching butt-joint interface ( n = 41). Standardized clinical, radiologic, and esthetic parameters were applied. The facial bone crest dimensions were assessed by CBCT. Results Soft tissue parameters and pink esthetic scores yielded no significant differences between the two designs. Major differences were only observed at the implant shoulder level. The height of the facial bone crest for the BL design was located 0.2 mm above the implant shoulder level, whereas for the STL design, its location was 1.6 mm below. The width of the peri-implant saucer-like bone defect was reduced by 40% for the BL implant design. No differences were observed 2 mm below the shoulder level. Conclusions The results of this comparative study suggest better crestal bone stability on the facial aspect of single implant sites in the esthetic zone for a BL design with a platform-switching concept when compared with STL implants with a butt-joint interface. [ABSTRACT FROM AUTHOR]

Background Buccal plate thickness is of clinical importance in treatment planning for implants. The purpose of this study was to evaluate the buccal plate thickness in posterior dentate areas of both the maxilla and mandible using cone beam computed tomography in order to estimate the approximate distributions of this anatomic variable. Methods Two hundred and sixty-five subjects were included for a total of nine hundred and thirty-four roots assessed by cone beam computed tomography. CBCT scans were taken and evaluated at the ideal buccolingual cross-sections of each root at 1 mm, 3 mm, and 5 mm apical to the alveolar crest to measure buccal plate thickness. Data are reported by geometric means and 95% confidence intervals. Results Both arches demonstrated increasing buccal plate thickness from anterior to posterior. Maxillary teeth had a significant decrease in thickness from coronal to apical along the tooth root ( P < 0.001), except at second molars. The first premolar and mesial root of the first molar were significantly thinner than all other roots in the maxilla. Conversely, the mandible demonstrated a significant increase in buccal plate thickness from coronal to apical ( P < 0.001). The premolars were significantly thinner than all other roots. Age and sex were found to have limited impact on buccal plate thickness in both arches. Conclusions Buccal plate thickness is highly dependent upon the arch position, tooth location, and measurement point, but age and sex have limited impact. [ABSTRACT FROM AUTHOR]

Introduction The aim of this pilot study was to examine the kinetics of alterations in alveolar ridge width and height following tooth extraction with and without ridge preservation, using anorganic bovine bone mineral ( ABBM) and a novel device ( Socket KAP™) designed for obturation of socket orifice. Materials and methods Maxillary left and right PM1 and mandibular right PM2 and PM4 were extracted on six beagle dogs and treated as follows: Group A: negative control;, Group B: Socket KAP™ alone;, Group C: ABBM + Socket KAP™., Serial cone-beam computed tomography ( CBCT) was taken at 0-, 1-, 2-, 4-, 8- and 12-week intervals to calculate the rate of alveolar bone loss, followed by histologic and histomorphometric analyses at 12 weeks. Across group outcomes were compared. Results Without additional intervention, the crestal-most 3 mm of alveolar bone width lost approximately 0.21-0.28 mm per week. The rate of alveolar buccal bone height loss was 0.19 mm per week. Comparatively, in group C, the alveolar bone was relatively stable, with loss of only 0.003-0.13 mm of width and 0.12 mm of height per week. These differences were statistically significant. The alveolar bone in sites treated by Socket KAP™ alone was significantly different from control only at select time points and locations of the ridge, presumably due to small sample size. Conclusion Without additional intervention, tooth extraction was accompanied by rapid loss of alveolar ridge width and height. Applications of Socket KAP™ and ABBM were effective in reducing alveolar crestal width and height loss following tooth extraction. [ABSTRACT FROM AUTHOR]

Objectives To evaluate the accuracy of measuring peri-implant buccal bone when using three different computed tomography devices. Materials and methods Sixty tissue-level or bone-level dental implants were placed in bovine ribs with either buccal bone full coverage, dehiscence or fenestration. For each site, the distance from the bone defect to the implant neck and the buccal bone thickness 1 mm apical to the crest were measured using a calliper. Subsequently, all sites were scanned in a reproducible position using a multi-slice computed tomography ( CT) (Brightspeed, voxel size 0.625 mm) and two cone-beam computed tomography devices (i-CAT NG, voxel size 0.3 mm and Newtom VGi, voxel size 0.2 mm). Bone thickness was measured on images from the three systems similar to direct measurements and differences were evaluated. Factors that could influence the buccal bone identification were assessed by multiple binary logistic regression. Results Buccal bone ranged from 0.1 mm to 2.75 mm in thickness and was not visible in 68%, 63% and 60% of cases when using CT, i-CAT and Newtom, respectively. For each mm of bone thickness increment, the odds of radiographic identification increased by 30.6 ( P < 0.001). Bone defects negatively affected radiographic visibility ( P < 0.05). All devices underestimated bone dimensions although differences among them were not significant. Conclusions Within these experimental conditions, the investigated devices have equivalent low accuracy in diagnosing peri-implant buccal bone. Accuracy was significantly influenced by buccal bone thickness, especially if <1 mm, and in presence of peri-implant marginal defects. [ABSTRACT FROM AUTHOR]

Objectives This case series investigated by means of CBCT, buccal bone three-dimensional anatomy at delayed, two-stage implants in the maxillary incisal tooth region. Moreover, the relation between buccal bone anatomy and soft tissue aesthetics was assessed. Material and methods Twelve implants were analysed after on average 8.9 years in function. Baseline and re-evaluation photographs were assessed using the pink aesthetic score ( PES). Marginal bone changes were measured from intraoral X-rays. The buccal bone volume associated with the implant and the implant surface not covered by visible buccal bone was computed on CBCT data sets. Buccal bone thickness and level were assessed, as well as the thickness of the crest distally and mesially of the implant. Changes in soft tissue forms and correlation between aesthetics and bone anatomy were calculated by nonparametric statistics. Results Buccal bone level was located 3.8 mm apical of the implant shoulder, and none of the implants had complete bone coverage. Buccal bone volume was 144.3 mm3, and 4.29 mm3 in the more coronal 2 mm portion. PES did not differ at re-evaluation (9.7) and baseline (9.2). PES was directly correlated with crestal thickness mesially and distally of the implant shoulder. No other significant correlations were observed between bone anatomy and PES or buccal peri-implant health. Marginal bone gain over time was associated with greater coronal bone volume buccally and with greater buccal and marginal bone thickness, while loss was related to less or no bone. Conclusions Within present limitations, acceptable and stable aesthetics are not jeopardized by a thin or missing buccal bone. [ABSTRACT FROM AUTHOR]

Objectives To evaluate the impact of cone beam computed tomography (CBCT) imaging on treatment planning regarding augmentation procedures for implant placement. Material and methods Panoramic radiographs and CBCT images of 40 patients requesting single-tooth implants in 59 sites were retrospectively analyzed by six specialists in implantology, and treatment planning was performed. Therapeutic recommendations were compared with the surgical protocol performed initially. Results Bone height estimation from panoramic radiographs yielded to higher measures and greater variability compared to CBCT. The suggested treatment plan for lateral and vertical augmentation procedures based on CBCT or panoramic radiographs coincided for 55-72% of the cases. A trend to a more invasive augmentation procedure was seen when planning was based on CBCT. Panoramic radiography revealed 57-63% (lateral) vs. 67% (vertical augmentation) congruent plans in agreement with surgery. Among the dissenting sites, there was a trend toward less invasive planning for lateral augmentation with panoramic radiographs, while vertical augmentation requirements were more frequently more invasive when based on CBCT. Conclusions Vertical augmentation requirements can be adequately determined from panoramic radiographs. In difficult cases with a deficient lateral alveolar bone, the augmentation schedule may better be evaluated from CBCT to avoid underestimation, which occurs more frequently when based on panoramic radiographs only. However, overall, radiographic interpretation and diagnostic thinking accuracy seem to be mainly depending on the opinion of observers. [ABSTRACT FROM AUTHOR]

Aim To test whether the mandibular retromolar region renders different results from the chin region with respect to the amount of bone available for the harvesting of block grafts. Material and methods Sixty cone beam computed tomography ( CBCT) scans of mandibles of adult patients without pathologic findings in the chin and retromolar region were included. According to the number of mandibular teeth, 20 CBCT data sets were allocated to each of the following groups: group M1: dentition 36-46; group M2: dentition 37-47; and group M3: dentition 38-48. For the potential donor sites in the chin and the retromolar regions, the volume ( VChin, VRetro), the length ( LChin, LRetro), the height ( HChin, HRetro) and the width ( HChin, HRetro) were assessed using a computer software. Moreover, the chin was examined for the presence and the localization of the mandibular incisive canal. To compare the donor sites in the chin and in the retromolar regions, the quotients VRetro/ VChin, LRetro/ LChin, HRetro/ HChin and WRetro/ WChin were calculated and tested using the Wilcoxon signed-rank test or the sign test. Results The mean bone volume VChin measured 3.5 ± 1.3 cm3 ( SD), whereas the overall VRetro amounted to 1.8 ± 1.1 cm3 ( SD). VRetro amounted to 2.6 ± 1.4 cm3 ( SD) in the group M1, 1.8 ± 0.5 cm3 in the group M2 and 1.0 ± 0.4 cm3 in the group M3. For the group M1, VRetro/ VChin measured 82 ± 39% ( P = 0.036). VRetro/ VChin reached 57 ± 20% in the group M2 and 32 ± 12% in the group M3 ( P < 0.001). The mandibular incisive canal was detected in 97% of the CBCT scans. The distance between the mandibular incisive canal and the apices of the central incisors measured 10.5 ± 3.5 mm. Conclusion The amount of bone available for the harvesting of cortico-cancellous blocks in the chin region was superior in comparison with the mandibular retromolar region. In the absence of the second and the third molars, the amount of bone harvestable in the retromolar region reached approximately 80% of the bone volume available in the chin region. In the majority of the cases, the mandibular incisive canal was detected within the donor site in the chin region. [ABSTRACT FROM AUTHOR]

Objectives The aims of this study were (i) to evaluate the efficacy of ridge preservation and repair procedures involving the application of Socket KAP™ and Socket KAGE™ devices following tooth removal and (ii) to evaluate alveolar bone volumetric changes at 6 months post-extraction in intact sockets or those with facial wall dehiscence defects using 3-dimensional pre- and postoperative CBCT data. Materials and Methods Thirty-six patients required 61 teeth extracted. Five cohorts were established: Group A: Intact Socket Negative Control Group B: Intact Socket + Socket KAP™ Group C: Intact Socket Filled with Anorganic Bovine Bone Mineral ( ABBM) + Socket KAP™ Group D: Facial Dehiscence Socket Negative Control Group E: Facial Dehiscence Socket Filled with ABBM + Socket KAP™ + Socket KAGE™. Preoperative CBCT scans were obtained followed by digital subtraction of the test teeth. At 6 months post-extraction, another CBCT scan was obtained. The pre- and postoperative scans were then superimposed, allowing highly accurate quantitative determination of the 3D volumetric alveolar bone volume changes from baseline through 6 months. Results Significant volumetric bone loss occurred in all sockets, localized mainly in the 0-3 mm zone apical to the ridge crest. For intact sockets, Socket KAP™ + ABBM treatment led to a statistically significant greater percentage of remaining mineralized tissue volume when compared to negative control group. A significant difference favoring Socket KAP™ + Socket KAGE™ + ABBM treatment was observed for sockets with facial dehiscence defects compared to the negative control group. Conclusions Socket KAP™, with ABBM, appears effective in limiting post-extraction volumetric bone loss in intact sockets, while Socket KAP™ + Socket KAGE + ABBM appears effective in limiting post-extraction bone loss in sockets with dehiscence defects. [ABSTRACT FROM AUTHOR]

Objectives To investigate the influence of sinus floor elevation ( SFE) on sinus physiology, including Schneiderian membrane thickness ( MT) and ostium patency, using cone beam computed tomography ( CBCT). Materials and methods Based on pre-established selection criteria, 53 patients in combination with 53 sinuses were referred for SFE with a lateral approach using deproteinized bone mineral. CBCT was performed prior to, immediately after surgery and before staged implant placement. The Schneiderian MT of the elevated region, ostium patency, and other clinical data was evaluated. Results The two-stage sinus augmentation technique was applied in 33 males and 20 females. Four membrane perforations were observed during the surgical procedure. The Schneiderian membrane exhibited significant swelling immediately after augmentation ( P < 0.0001), but this difference disappeared after a mean healing period of 7.51 months. The corresponding changes were also observed for ostium patency with a tendency of transient obstruction after surgery. Sinuses with flat mucosal thickening or pseudocysts did not present a liability of perforation compared to the normal cases, and the augmentation procedure was not likely to deteriorate the pathology of mucosal thickening or pseudocysts. Conclusions The results show that SFE with a lateral approach has no significant influence on MT and ostium patency after the healing period except for postoperative transient swelling and obstruction. Thickened membranes and antral pseudocysts in a small size might not be contraindications to SFE from the standpoint of the surgical impact on the Schneiderian membrane. [ABSTRACT FROM AUTHOR]

Objectives To investigate: (1) sinus membrane thickness in patients receiving lateral window sinus augmentation via cone-beam computed tomography ( CBCT) and (2) the influence of Schneiderian membrane thickness upon membrane perforation during lateral window approach. Material and methods A total of 73 subjects with 81 sinus lift procedures between years 2010 and 2013 were recruited consequently. Each patient selected had CBCT images in initial and immediately after surgery. The values and correlation between variables of membrane thickness, perforation rate, membrane morphology, residual bone height, and elevated bone height were evaluated. Results The mean thickness of the Schneiderian membrane was 1.32 ± 0.87 mm. Perforation rate was lowest (7.14%) when membrane thickness was 1-1.5 mm. As membrane became thicker (≥2 mm) or thinner (<1 mm), the perforation rate increased abruptly. When examined the membrane thickness category, Class B (between ≥1 mm and <2 mm) had the lowest perforation rate. Statistically significant correlation was found between the perforation and the membrane thickness. The amount of the remaining bone height did not significantly correlate to the membrane thickness nor influence the membrane perforation. Conclusions This study demonstrated that membrane thickness was related to the sinus perforation during lateral window sinus augmentation. The perforation rate was lowest when the membrane thickness was 1-1.5 mm. [ABSTRACT FROM AUTHOR]

Objectives Two- and three-dimensional radiographic techniques are available to determine peri-implantitis-related bone loss around dental implants. Purpose To compare the performance of detecting different peri-implant bone defects in intraoral radiography ( IR), panoramic radiography ( PR), Cone Beam Computer Tomography ( CBCT) and Computer Tomography ( CT). Material and methods Six implants were inserted under ideal conditions into the lower jaw of an edentulous human cadaver. IR, PR, CBCT and CT were performed. Two-wall, three-wall and four-wall defects with 1 mm depth were artificially created around two of the implants (one anterior and one posterior), and radiographies were repeated. The identical set-up was used for 3-mm-deep bone defects. All images were presented to seven observers. Sensitivity ( SN) and specificity ( SP) were determined for each modality, defect type and depths, and likelihood ratios were calculated. Results The highest sensitivity was found with IR and CBCT for 1 mm (0.67; 0.68) and 3-mm defects (0.81; 0.79). The highest specificity was found with IR for both defect depths (0.51). The best classification of defect type revealed PR for both 1-mm and 3-mm-deep defects. Both likelihood ratios ( LR+ and LR−) were best for IR with 1-mm (1.37 and 0.65) and with 3-mm defects (1.65 and 0.37). Conclusions IR should still be recommended as favourable method evaluating bone loss around dental implants, while CT demonstrated the lowest performance in detecting peri-implant bone defects. [ABSTRACT FROM AUTHOR]