The comparison of visibility of the maxillary sinus septa between cone-beam computed tomography scans and panoramic radiograph images as dependent on the cortical bone thickness: a retrospective comparative study.

PURPOSE: To analyze the visibility of the maxillary sinus septa (MSS) in panoramic radiography (PR) versus cone beam computed tomography (CBCT) and to investigate whether the buccal cortical bone thickness (BT) or the septa dimensions influence their visibility. METHODS: Corresponding PR and CBCT images of 355 patients were selected and examined for MSS visibility. The septa dimensions (width, height, depth) and the BT were measured. Results were analysed statistically. RESULTS: Comparing the corresponding regions on CBCT and PR, 170 MSS were identified; however, only 106 of these were also visible using PR. The MSS visibility was significantly higher on CBCT versus PR images (P1: p = 0.039, P2: p = 0.015, M1: p = 0.041, M2: p = 0.017, M3: p = 0.000), except region C (p = 0.625). Regarding the measurements of MSS dimensions, only the height in region M1 (p = 0.013) and the width in region P2 (p = 0.034) were significantly more visible on CBCT. The BT in the area of the MSS was found to have a marginal influence on its visibility on the PR images only in regions M3 and M1 (M3: p = 0.043, M1: p = 0.047). In terms of MSS visibility based on the dimensions, significance was found for all three influencing variables only in region P2 (width; p = 0.041, height; p = 0.001, depth; p = 0.007). There were only isolated cases of further significance: M3 for width (p = 0.043), M2 for height (p = 0.024), and P1 for depth (p = 0.034), no further significance was noted. CONCLUSION: MSS visibility appears significantly higher on CBCT versus PR images. It is concluded that the septa dimensions and BT can influence MSS visibility on PR images just in certain regions.

Comparative diagnosis of the alveolar antral artery canal in the lateral maxillary sinus wall in corresponding panoramic radiography and cone-beam computed tomography.

PURPOSE: Sinus lift operations are a tried and tested means of providing adequate implant prosthetics to patients with compromised jawbones. Knowledge of the arterial supply of the maxillary sinus region is essential for surgical treatment in this area. The aim of the present comparative study was to determine whether alveolar antral artery (AAA) canal can be diagnosed both in corresponding panoramic radiography (PR) and cone-beam computed tomography (CBCT). METHODS: A total of 335 patients with 635 sites and corresponding maxillary sinus in both PR and CBCT were selected and examined for AAA canal visibility. RESULTS: The visibility of the AAA canal was significantly higher in CBCT than in PR. A total of 154 (46.0%) AAA canals could be identified in the maxillary sinus on the right. However, only four (1.2%) of these were also visible in PR. The detected values of the AAA canals in the maxillary sinus on the left in the PR and CBCT images were similar to those of the right. While 164 AAA canals (49%) were observed in CBCT images, only 1 (0.3%) was identifiable in PR. CONCLUSIONS: The results show that CBCT can be recommended for visualising the AAA canal when surgically planning sinus augmentation procedures.

Evaluation of the contour of edentulous jaw sections in the transversal plane and the buccolingual vertical-level disparity in CBCT and panoramic radiography images: a retrospective comparative study.

PURPOSE: This study investigates whether edentulous jaw sections in the planned implant position exhibit jaw contours funnel-shaped or exhibit pronounced retraction of the jaw (unusual jaw contours) in the transversal plane of the three-dimensional (3D) images, not visible in two-dimensional (2D) images. METHODS: A total of 335 patients with an edentulous section of the jaw that required dental implants were selected. Anonymised radiologic patients' data were collected, comprising cone-beam computed tomography (CBCT) images of the edentulous jaw sections. In the first stage, unusual jaw contours were examined, including funnel-shaped or pronounced retraction of the jaw and hypodense regions with an undercut and/or bone deficit. In the second stage, the variation in the height of the alveolar ridge between the lingual and buccal contour in the edentulous jaw sections was assessed. RESULTS: The CBCT images of an unusual jaw contour were observed in 8 cases (2.4%) in the maxilla on the left and 10 cases (3%) in the maxilla on the right. In the mandible, a jaw contour deviates in 39 cases (12.1%) on the left side and 39 cases (12.1%) on the right side. A height difference was detected in the upper jaw in 307 cases and the lower jaw in 265 cases. The discrepancy was 2.09 mm (± 2.25 mm) in the maxilla and 3.97 mm (± 3.45 mm) in the mandible. CONCLUSIONS: The CBCT scan provides useful information to avoid complications in the preoperative planning phase and surgical planning in implant dentistry.

The comparison of roof visibility of the mandibular canal between cone-beam computed tomography scans and panoramic radiograph images as dependent on the cortical bone thickness of the mandible.

BACKGROUND: Accurate detection of the mandibular canal is a difficult process despite cutting-edge radiographic methods. The present study analyses whether mandibular canal roof visibility is comparable to panoramic radiography (PR) and cone-beam computed tomography (CBCT) and, further, examines whether the visibility in PR and CBCT is dependent on cortical bone thickness in the mandible. METHODS: This study was conducted on a group of 343 selected patients. It incorporated anonymised data on 343 patients in which a CBCT and PR were available. The first stage examines whether the mandibular canal roof visibility is comparable to PR and CBCT. In the second stage, measurements of cortical bone thickness showed buccal and lingual in the P2, M1, M2 and M3 teeth areas, both to the left and right of the mandible in CBCT images. Statistical analysis was supported by statistical software (IBM SPSS 25; Armonk, NY, USA). RESULTS: The mean age of the patients was 58.8 years with an almost equal gender distribution. When performing a McNemar test on the P2, M1, M2 and M3 on both the left and right jaws, the difference between the two image modalities, with regard to the visibility of the canal roof, was found to be significant (McNemar test, p < 0.001). Statistically (U test, p≥0.05), it follows that the thickness of the cortical bone of the mandible exerts no influence on the visibility of the roof of canalis mandibulae in PR and CBCT images. CONCLUSION: We conclude that the visibility of the mandibular canal in PR and CBCT rays is not identical, and that the thickness of the cortical bone in the mandible does not represent a factor affecting the visibility of the roof of the mandibular canal.

Implant insertion using an orientation template and a full-guiding template - A prospective model analysis in a cohort of dentists participating in an implantology curriculum.

BACKGROUND: Dental implantology has become an established option for treating tooth loss over the recent decades. Before inserting an implant in a clinical situation, theoretical and practical training is recommended. Different methods are available to give assistance in determining the correctly planned implant position. In this study, two different guiding methods were assessed considering their accuracy for implant insertion in a group of dentists. METHODS: After three-dimensional planning of the implant positions, two surgical templates were manufactured as follows: in region 34 a stereolithographic template was used to perform a full-guided implant insertion, in region 44 a CAD/CAM milled template was used to determine the implant position and subsequently, perform a free-hand insertion. In total, 86 implants were placed in mandibular models by 43 dentists participating in a postgraduate curriculum. The differences between planned and achieved implant positions were measured and statistically analyzed. RESULTS: The implants inserted fully-guided showed a lower deviation of the three-dimensional angulation (2.266 ± 1.443 degrees vs. 7.954 ± 4.372 degrees) and the cumulated mismatch of the implant position (0.547 ± 0.237 mm vs. 1.160 ± 0.427 mm) compared to the free-handed mode. For the angulation and the mismatch at the implant base the differences were statistically significant (p < 0.001). CONCLUSIONS: Within the limits of the study it can be summarized that the full-guided implant insertion leads to a higher transfer accuracy compared to the free-hand method in a cohort of dentist inexperienced in dental implantology. However, the clinical effect has to be discussed as the study was performed using artificial mandibles and ideal conditions.

Detection and measurements of apical lesions in the upper jaw by cone beam computed tomography and panoramic radiography as a function of cortical bone thickness.

OBJECTIVES: In the current literature, cone beam computed tomography (CBCT) seems to be more accurate in detecting apical lesions (AL) than two-dimensional radiographs. Cortical bone thickness might have an influence on AL visibility. Therefore, the purpose of the study was to directly compare the diagnostic accuracy of panoramic radiography (PANO) and CBCT in detecting AL in the upper jaw and determine the influence of cortical bone thickness on AL visibility. MATERIALS AND METHODS: Anonymised digital images of 351 patients who received a CBCT image and a panoramic radiograph within 90 days were examined for AL in the upper jaw. The analysis was conducted by a trained examiner and reviewed by an expert in dental radiology. Further, the dimensions of AL and cortical bone thickness in the region affected by AL were measured to determine their influence on visibility. Statistical analysis was carried out by means of statistical software (IBM SPSS 25; Armonk, NY, USA). RESULTS: The mean age of the patients was 58.9 years with an almost equal gender distribution. A total of 2223 teeth in the upper jaw were included in the final analysis. CBCT detected AL on 144 teeth (6.5%), of which only 23 were also visible on a PANO. The difference between both methods was significant (p < 0.001). The dimensions of AL measured within a PANO were approximately twice as high as those measured by CBCT. However, the difference was not significant (p ≥ 0.005). Cortical bone thickness had no influence on AL visibility. CONCLUSIONS AND CLINICAL RELEVANCE: Panoramic radiographs are unsuitable for a reliable diagnosis of AL in the upper jaw, while CBCT leads to a better visualisation of AL. Bone thickness has no significant influence on AL visibility with either imaging method.

Locator® versus ceramic/electroplated double-crown attachments: a prospective study on the intraindividual comparison of implant-supported mandibular prostheses.

OBJECTIVES: Implant-supported overdentures are an established dental treatment mode. The aim of this prospective study was and interindividual comparison of patient satisfaction with restorations retained by a prefabricated and thus inexpensive attachment system (Locator®) or with a technologically complex and thus expensive attachment system (ceramic/electroplated double crowns) with similar retentive performance. MATERIALS AND METHODS: Twelve patients received a Locator and a double-crown prosthesis in a crossover study for test periods of 3 months each. The main target parameter was the patient's final decision in favor of one of the two prosthesis types. RESULTS: After completing both test phases, seven patients opted for the Locator prosthesis and five patients opted for the double-crown prosthesis. CONCLUSION: Given the predominant lack of statistically significant differences, the two types of prostheses can be described as equivalent. A recommendation in favor of the Locator prosthesis can be motivated by its lower cost. CLINICAL RELEVANCE: The results of the study show that the more cost-effective variant was comparable to the more expensive double-crown prosthesis under the conditions prevailing in the study. Depending on the indication, this may influence the decision-making process in daily clinical practice and support the clinician's patient information and consultation efforts.

Thirteen-year follow-up study of resin-bonded fixed partial dentures.

OBJECTIVE: The technique of resin-bonded fixed partial dentures (RBFPD) is a well-accepted clinical technique to replace missing teeth. The survival rates reported in the literature vary widely, and the conclusions are sometimes conflicting. This study presents the clinical long-term performance of silicoated RBFPDs and also determines the main cause of failure. METHOD AND MATERIALS: Sixty-one patients with a total of 74 RBFPDs were either examined or requested to complete a questionnaire regarding their fixed partial dentures. Sixty-four were placed in the anterior region, and 10 in the posterior region. No more than one missing tooth in the posterior area and two missing teeth in the anterior region were replaced with RBFPDs. A retentive preparation was made on the abutment teeth. All the RBFPDs were adhesively seated. RESULTS: Eighteen RBFPDs failed after a mean observation time of 7.8 years (nine retention losses of one or more retainers, six carious lesions, and three veneer fractures occurred). Seven RBFPDs were rebonded, whereas the remaining 11 failures had to be replaced with conventional FPDs. Fifty-six RBFPDs were primary restorations, and seven secondary RBFPDs were used after the loss of the primary restoration. A mean survival rate better than 69% after a 13-year observation period was calculated. Including the rebonded restorations, a mean functional survival rate of 83% was estimated. A total of 18 failures (24.3%) of all restorations were observed, the main cause being loss of retention. CONCLUSION: Silicoated RBFPDs are a viable treatment means with an acceptable success expectancy.