Dental and Maxillofacial Cone Beam CT-High Number of Incidental Findings and Their Impact on Follow-Up and Therapy Management.

Cone beam computed tomography (CBCT) is increasingly used for dental and maxillofacial imaging. The occurrence of incidental findings has been reported, but clinical implications of these findings remain unclear. The study's aim was to identify the frequency and clinical impact of incidental findings in CBCT. A total of 374 consecutive CBCT examinations of a 3 year period were retrospectively evaluated for the presence, kind, and clinical relevance of incidental findings. In a subgroup of 54 patients, therapeutic consequences of CBCT incidental findings were queried from the referring physicians. A total of 974 incidental findings were detected, involving 78.6% of all CBCT, hence 2.6 incidental findings per CBCT. Of these, 38.6% were classified to require treatment, with an additional 25.2% requiring follow-up. Incidental findings included dental pathologies in 55.3%, pathologies of the paranasal sinuses and airways in 29.2%, osseous pathologies in 14.9% of all CBCT, and findings in the soft tissue or TMJ in few cases. Clinically relevant dental incidental findings were detected significantly more frequently in CBCT for implant planning compared to other indications (60.7% vs. 43.2%, p < 0.01), and in CBCT with an FOV ≥ 100 mm compared to an FOV < 100 mm (54.7% vs. 40.0%, p < 0.01). Similar results were obtained for paranasal incidental findings. In a subgroup analysis, 29 of 54 patients showed incidental findings which were previously unknown, and the findings changed therapeutical management in 19 patients (35%). The results of our study highlighted the importance of a meticulous analysis of the entire FOV of CBCT for incidental findings, which showed clinical relevance in more than one in three patients. Due to a high number of clinically relevant incidental findings especially in CBCT for implant planning, an FOV of 100 × 100 mm covering both the mandible and the maxilla was concluded to be recommendable for this indication

The randomized shortened dental arch study (RaSDA): design and protocol

<p>Abstract</p> <p>Background</p> <p>Various treatment options for the prosthetic treatment of jaws where all molars are lost are under discussion. Besides the placement of implants, two main treatment types can be distinguished: replacement of the missing molars with removable dental prostheses and non-replacement of the molars, i.e. preservation of the shortened dental arch. Evidence is lacking regarding the long-term outcome and the clinical performance of these approaches. High treatment costs and the long time required for the treatment impede respective clinical trials.</p> <p>Methods/design</p> <p>This 14-center randomized controlled investigator-initiated trial is ongoing. Last patient out will be in 2010. Patients over 35 years of age with all molars missing in one jaw and with at least both canines and one premolar left on each side were eligible. One group received a treatment with removable dental prostheses for molar replacement (treatment A). The other group received a treatment limited to the replacement of all missing anterior and premolar teeth using fixed bridges (treatment B). A pilot trial with 32 patients was carried out. Two hundred and fifteen patients were enrolled in the main trial where 109 patients were randomized for treatment A and 106 for treatment B. The primary outcome measure is further tooth loss during the 5-year follow-up. The secondary outcome measures encompassed clinical, technical and subjective variables. The study is funded by the Deutsche Forschungsgemeinschaft (German Research Foundation, DFG WA 831/2-1, 2-2, 2-3, 2-4, 2-5).</p> <p>Discussion</p> <p>The particular value of this trial is the adaptation of common design components to the very specific features of complex dental prosthetic treatments. The pilot trial proved to be indispensable because it led to a number of adjustments in the study protocol that considerably improved the practicability. The expected results are of high clinical relevance and will show the efficacy of two common treatment approaches in terms of oral health. An array of secondary outcome measures will deliver valuable supplementary information. If the results can be implemented in the clinical practice, the daily dental care should strongly profit thereof.</p> <p>Trial registration</p> <p>The trial is registered at ClinicalTrials.gov under ISRCTN68590603 (pilot trial) and ISRCTN97265367 (main trial).</p

Accuracy of Dynamic Computer-Assisted Implant Placement: A Systematic Review and Meta-Analysis of Clinical and In Vitro Studies

The aim of this systematic review and meta-analysis is to analyze the accuracy of implant placement using computer-assisted dynamic navigation procedures. An electronic literature search was carried out, supplemented by a manual search. The literature search was completed in June 2020. The results of in vitro and clinical studies were recorded separately from each other. For inclusion in the review, the studies had to examine at least the prosthetically relevant parameters for angle deviation, as well as global deviation or lateral deviation at the platform of the implant. Sixteen of 320 articles were included in the investigation: nine in vitro and seven clinical studies. The meta-analysis showed values of 4.1° for the clinical studies (95% CI, 3.12–5.10) and 3.7° for the in vitro studies (95% CI, 2.31–5.10) in terms of the angle deviation. The global deviation at the implant apex of the implant was 1.00 mm for the clinical studies (95% CI, 0.83–1.16) and 0.91 mm for the in vitro studies (95% CI, 0.60–1.12). These values indicate no significant difference between the clinical and in vitro studies. The results of this systematic review show a clinical accuracy of dynamic computer-assisted navigation that is comparable to that of static navigation. However, the dynamic navigation systems show a great heterogeneity that must be taken into account. Moreover, currently there are few clinical data available. Therefore, further investigations into the practicability of dynamic navigation seem necessary

Accuracy of Dynamic Computer-Assisted Implant Placement: A Systematic Review and Meta-Analysis of Clinical and In Vitro Studies

The aim of this systematic review and meta-analysis is to analyze the accuracy of implant placement using computer-assisted dynamic navigation procedures. An electronic literature search was carried out, supplemented by a manual search. The literature search was completed in June 2020. The results of in vitro and clinical studies were recorded separately from each other. For inclusion in the review, the studies had to examine at least the prosthetically relevant parameters for angle deviation, as well as global deviation or lateral deviation at the platform of the implant. Sixteen of 320 articles were included in the investigation: nine in vitro and seven clinical studies. The meta-analysis showed values of 4.1° for the clinical studies (95% CI, 3.12–5.10) and 3.7° for the in vitro studies (95% CI, 2.31–5.10) in terms of the angle deviation. The global deviation at the implant apex of the implant was 1.00 mm for the clinical studies (95% CI, 0.83–1.16) and 0.91 mm for the in vitro studies (95% CI, 0.60–1.12). These values indicate no significant difference between the clinical and in vitro studies. The results of this systematic review show a clinical accuracy of dynamic computer-assisted navigation that is comparable to that of static navigation. However, the dynamic navigation systems show a great heterogeneity that must be taken into account. Moreover, currently there are few clinical data available. Therefore, further investigations into the practicability of dynamic navigation seem necessary

Accuracy of Dental Implant Placement with Dynamic Navigation—Investigation of the Influence of Two Different Optical Reference Systems: A Randomized Clinical Trial

This randomized prospective clinical study aims to analyze the differences between the computer-assisted planned implant position and the clinically realized implant position using dynamic navigation. In the randomized prospective clinical study, 30 patients were recruited, of whom 27 could receive an implant (BLT, Straumann Institut AG, Basel, Switzerland) using a dynamic computer-assisted approach. Patients with at least six teeth in their jaws to be implanted were included in the study. Digital planning was performed using cone beam tomography imaging, and the visualization of the actual situation was carried out using an intraoral scan. Two different workflows with differently prepared reference markers were performed with 15 patients per group. The actual clinically achieved implant position was recorded with scan bodies fixed to the implants and an intraoral scan. The deviations between the planned and realized implant positions were recorded using evaluation software. The clinical examinations revealed no significant differences between procedures A and B in the mesiodistal, buccolingual and apicocoronal directions. For the mean angular deviation, group B showed a significantly more accurate value of 2.7° (95% CI 1.6–3.9°) than group A, with a value of 6.3° (95% CI 4.0–8.7°). The mean 3D deviation at the implant shoulder was 2.35 mm for workflow A (95% CI 1.92–2.78 mm) and 1.62 mm for workflow B (95% CI 1.2–2.05 mm). Workflow B also showed significantly higher accuracy in this respect. Similar values were determined at the implant apex. The clinical examination shows that sufficiently accurate implant placement is possible with the dynamic navigation system used here. The use of different workflows sometimes resulted in significantly different accuracy results. The data of the present study are comparable with the published findings of other static and dynamic navigation procedures

Accuracy of Computer-Assisted Dynamic Navigation in Implant Placement with a Fully Digital Approach: A Prospective Clinical Trial

Background: This prospective clinical study aimed to investigate a possible deviation between the digitally planned implant position and the position achieved using dynamic navigation. The aim of the study was to establish clinical effectiveness and precision of implantation using dynamic navigation. Methods: Twenty consecutive patients received an implant (iSy-Implantat, Camlog, Wimsheim, Germany). One screw implant was placed in one jaw with remaining dentition of at least six teeth. The workflow was fully digital. Digital implant planning was conducted using cone-beam computed tomography (CBCT) and an intraoral scan of the actual condition. Twenty implants were subsequently placed using a dynamic computer-assisted procedure. The clinical situation of the implant position was recorded using an intraoral scan. Using these data, models were produced via 3D printing, and CBCTs of these models were made using laboratory analogs. Deviations of the achieved implant position from the planned position were determined using evaluation software. Results: The evaluation of 20 implants resulted in a mean angle deviation of 2.7° (95% CI 2.2–3.3°). The 3D deviation at the implant shoulder was 1.83 mm (95% CI 1.34–2.33 mm). No significant differences were found for any of the parameters between the implantation in the upper or lower jaw and an open or flapless procedure (p-value &lt; 0.05). Conclusion: The clinical trial showed that sufficiently precise implantation was possible with the dynamic navigation system used here. Dynamic navigation can improve the quality of implant positioning. In particular, the procedure allows safe positioning of the implants in minimally invasive procedures, which usually cannot be performed freehand in this form. A clinical benefit and effectiveness can be determined from the results

Technical Complications of Removable Partial Dentures in the Moderately Reduced Dentition: A Systematic Review

The aim of this study was to conduct a systematic literature review with a subsequent meta-analysis on the technical complications and failures of removable partial denture (RPD) therapy in the moderately reduced dentition. A systematic literature search of established medical databases, last updated 06/2022, was conducted. RCTs and prospective and retrospective studies were included that had information on technical complications and failures of RPDs, at least 15 participants, an observation period of at least two years and a drop-out rate of less than 25%. Publications were selected on the title, abstract and full-text level by at least three of the participating authors. The evidence of the included studies was classified using the GRADE system. The bias risk was determined using the RoB2 tool and the ROBINS-I tool. Of 19,592 initial hits, 43 publications were included. Predominantly, retention of the prosthesis, retention loss of anchor crowns (decementations), fractures/repairs of frameworks, denture teeth, veneering or acrylic bases, and a need for relining were reported depending on prosthesis type and observation time. Focusing on technical complications and failures, only very heterogeneous data were found and publications with the highest quality level according to GRADE were scarce. Whenever possible, data on technical complications and failures should be reported separately when referencing the tooth, the prosthesis and the patient for comparability. Prostheses with differing anchorage types should be analyzed in different groups, as the respective complications and failures differ. A precise description of the kinds of complications and failures, as well as of the resulting follow-up treatment measures, should be given

Digital Evaluation of Vertical Ridge Augmentation with the Modified Shell Technique Using a Xenogeneic Bone Lamina: A Case Series

Vertical ridge augmentation is a demanding and technique-sensitive surgical procedure. In the present case series, cone beam CT (CBCT) scans from the clinical routine of patients treated using a novel approach for vertical bone augmentation were assessed. All patients showed a single-tooth class 5 defect and were treated using a modification of the original shell technique. Cortical bone plates were replaced with a lamina composed of a partially demineralized porcine xenograft. CBCT scans of six consecutive patients were treated with the lamina and particulate bone from the mandibular ramus prior to a single tooth implant in the anterior maxilla were included. Pre- and postsurgical CBCT data sets were superimposed and analyzed digitally using surface matching and Boolean subtraction. The volume of the grafted area was calculated with and without the xenograft. The vertical gain of the ridge height measured in this case series varied from 7 to 11.3 mm. The mean vertical gain was 8.97 mm. The mean volume including the xenograft was 382.59 mm3 (SD 73.39) and 250.84 mm3 (SD 53.67) without the lamina. The modified shell technique used in this case series for the vertical augmentation of single-tooth class 5 defects provided sufficient bone for single implant restorations

Er:YAG laser-induced damage to a dental composite in simulated clinical scenarios for inadvertent irradiation: an in vitro study

Inadvertent Er:YAG laser irradiation occurs in dentistry and may harm restorative materials in teeth. The aim of this in vitro study was to quantify Er:YAG laser-induced damage to a nanohybrid composite in simulated clinical scenarios for inadvertent direct and indirect (reflection) laser irradiation. The simulation was performed by varying the output energy (OE;direct˃indirect) reaching the specimen and the operating distance (OD;direct˂indirect). Composite specimens were irradiated by an Er:YAG laser. The ablation threshold was determined and clinically relevant parameters were applied (n = 6 for each OE/OD combination) for direct (OE: 570 mJ/OD: 10 mm, OE: 190 mJ/OD: 10 mm) and indirect irradiation (OE: 466 mJ/OD: 15 mm, OE: 57 mJ/OD: 15 mm, OE: 155 mJ/OD: 15 mm, OE: 19 mJ/OD: 15 mm). The extent of damage in the form of craters was evaluated using a laser scanning microscope (LSM) and a conventional light microscope (LM). The ablation threshold was determined to be 2.6 J/c

Stabilizing mandibular complete dentures by a single midline implant-influence on quality of life: 2-year results from a randomized clinical trial comparing different loading protocols.

OBJECTIVES The knowledge about the influence of dental treatment on health-related quality of life (HRQoL) is still limited. The aim of this multicenter randomized controlled clinical trial was to assess the effect of stabilizing an existing complete denture, by means of a single mandibular implant, on HRQoL. Furthermore, the impact of the loading protocol, i.e., immediate or delayed loading, in edentulous patients was evaluated. METHODS One hundred fifty-eight participants aged 60-89 years were randomly assigned to study group A (immediate loading; n = 81) and to group B (delayed loading; n = 78). All participants received a single midline implant in the mandible. The implants were either immediately loaded (group A) or after a closed healing period of 3 months (group B) by connecting the existing mandibular complete dentures to ball attachments. HRQoL was assessed with the Short Form-36 questionnaire of health (SF-36) at baseline, 4 months, and 24 months after implant loading. RESULTS Improvement of HRQoL by means of a single implant-retained mandibular overdenture could not be demonstrated after 4 and 24 months of implant loading. Furthermore, the application of two different loading protocols did not influence HRQoL ratings of study participants. CONCLUSION The loading protocol is not a factor, influencing HRQoL in patients treated by a single midline implant in the edentulous mandible. CLINICAL RELEVANCE A single midline implant in the edentulous mandible, stabilizing a mandibular complete denture, cannot be recommended for improving HRQoL