Sebastian Kühl

Bisphosphonate-related osteonecrosis of the jaws--a review.

The aim was to evaluate the knowledge about bisphosphonate-related osteonecrosis of the jaws (BRONJ). A bibliographic search in Medline, PubMed and the Cochrane Register of controlled clinical trials was performed between 2003 and 2010 by using the terms bisphosphonate and osteonecrosis of the jaw. The amount of publications per year, the type of journal for publication, and the evidence level of the trial were evaluated. Next to this the incidences and the success of treatment strategies for BRONJ were identified. A total of 671 publications were reviewed. Since 2006 more than 100 publications on BRONJ per year (with an upward trend) have been published, mostly in dental journals. The evidence level could be determined for 176 publications and only one grade Ia study was found. The studies showed a wide variety in design, most of them being retrospective. The incidence of BRONJ is strongly dependent on oral or intravenous application and varies between 0.0% and 27.5%. There is no scientific data to sufficiently support any specific treatment protocol for the management of BRONJ. Further clinical studies are needed to evaluate the incidence and treatment strategies at a higher level of evidence. Therefore uniform study protocols would be favourable.

Guided Endodontics: a novel treatment approach for teeth with pulp canal calcification and apical pathology

AIM To present a new treatment approach for teeth with pulp canal calcification (PCC) which require root canal treatment. CASE A 15-year-old male patient presented with pain of his upper right central incisor. The tooth showed signs of apical periodontitis. Due to PCC, location of the root canal was judged to be difficult and associated with a high risk of perforation. A cone beam computed tomography (CBCT) and an intra-oral surface scan were performed and matched using software for virtual implant planning. After planning the position of the drill for root canal location, a virtual template was designed, and the data were exported as an STL file and sent to a 3D printer for template fabrication. The template was positioned on the anterior maxillary teeth. A specific drill was used to penetrate through the obliterated part of the root canal and obtain minimally invasive access to the apical part. The root canal was accessible at 9 mm distance from the apex. Further root canal preparation was carried out using an endodontic rotary instrumentation system. After an interappointment dressing for 4 weeks, the root canal was filled with vertically condensed gutta-percha using an epoxy sealer. The access cavity was restored with a composite material. After 15 months, the patient was clinically asymptomatic with no pain on percussion. The radiograph showed no apical pathology. CONCLUSIONS The presented guided endodontic approach seems to be a safe, clinically feasible method to locate root canals and prevent root perforation in teeth with PCC.

Cost-effectiveness of Anterior Implants versus Fixed Dental Prostheses

For the restoration of an anterior missing tooth, implant-supported single crowns (ISCs) or fixed dental prostheses (FDPs) are indicated, but it is not clear which type of restoration is more cost-effective. A self-selected trial was performed with 15 patients with ISCs and 11 with FDPs. Patient preferences were recorded with visual analog scales before treatment, 1 month following restoration, and then annually. Quality-adjusted tooth years (QATYs) were estimated by considering the type of reconstruction for replacing the missing tooth and its effect on the adjacent teeth. A stochastic cost-effectiveness model was developed using Monte Carlo simulation. The expected costs and QATYs were summarized in cost-effectiveness acceptability curves. ISC was the dominant strategy, with a QATY increase of 0.01 over 3 years and 0.04 over 10 years with a higher probability of being cost-effective. While both treatment options provided satisfactory long-term results from the patient’s perspective, the lower initial costs, particularly laboratory fees, were responsible for the dominance of ISCs over FDPs.

Detection of peri-implant bone defects with different radiographic techniques – a human cadaver study

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.

Dental injury and its prevention in Swiss rugby.

OBJECTIVES   Rugby players are at a high risk of sustaining dental injury because of the high number of tackles implicit to the game. This study aimed to determine the frequency of injuries sustained by players in the Swiss rugby league. METHODS   During the 2010/11 season, 517 rugby players from 19 clubs were questioned about dental trauma as well as the use of mouthguards and other forms of body protection. The level of awareness about tooth avulsion and replantation was also assessed. Participants included athletes from four different leagues; National (155), Premier (122), Womens (90) and Juniors (150). RESULTS   Of the 517 players taking part in the survey, 54.4% had sustained at least one serious injury and 39.5% had sustained a facial injury. One hundred and thirty-nine athletes (37.3%) had observed another player sustain a dental injury during a game, whilst 35 (6.8%) had personally sustained one or more dental injuries. Dental injury rate was considerably higher amongst forwards than backs. Four hundred and fifty-six players (88.2%) wore a mouthguard of which three-quarters were tailor-made. Three hundred and thirteen players (60.5%) were aware that an avulsed tooth can be replanted; however, only 27 (5.2%) had heard of the tooth rescue boxes. These results demonstrate that, whilst general injuries occur with regularity in rugby, dental injuries are not amongst the most common forms. This is almost certainly attributable to the high level of mouthguard usage. Particularly for players in the junior league, in which the use of mouthguards was lowest, the risk of dental injury may be reduced by an increased level of education about tooth protection. CONCLUSIONS   To this end, an increased awareness about and usage of tooth rescue boxes would be desirable. It would seem sensible to make the wearing of mouthguards compulsory in contact sports such as rugby.

Clinical outcome in periradicular surgery: effect of patient- and tooth-related factors--a multicenter study.

OBJECTIVE To evaluate the effect of patient- and tooth-related factors on the outcome of apical surgery in a multicenter study. METHOD AND MATERIALS A total of 281 teeth in 255 patients undergoing periradicular surgery were investigated clinically and radiographically 6 to 12 months postoperatively. RESULTS The overall success rate was 88.0%. Sex was a significant (P = .024) predictor, with a success rate of 89.8% in females and 84.0% in males. The success rate was significantly higher in patients 31 to 40 years of age. The treatment of premolars resulted in a significantly higher success rate (91.9%) than the treatment of anterior teeth (86.1%, P = .042) and molars (86.4 %, P = .026). The loss of the buccal bone plate and the extension of apical osteolysis to the furcation area in molars resulted in a considerably lower success rate. Lesion size, preoperative pain, tenderness to percussion, fistula, and resurgery were significant factors. CONCLUSION There are several factors influencing the success rate of apical surgery that must be taken into account when considering apical surgery as a treatment alternative.

Technical Accuracy of Printed Surgical Templates for Guided Implant Surgery with the coDiagnostiXTM Software

Background Printing of templates for guided surgery represents an alternative to laboratory manufactured templates. Purpose To determine the technical accuracy of a virtually designed and printed surgical template for guided implant surgery based on a surface scan of a cast model using the coDiagnostiXTM software. Materials and Methods Cast models and the virtual planning data of nine patients receiving guided implant surgery with the coDiagnostiX software were analyzed. The original cast models were equipped with three titanium pins and scanned with a three-dimensional scanner. The scans were uploaded in the coDiagnostiX software and the virtual surgical templates were designed including the sleeves at their original positions. After printing the surgical templates, the sleeve positions were determined by optical scanning, and deviations were calculated and compared with the virtual positions of the sleeves. Results The sleeves showed a mean three-dimensional deviation of 0.22 mm (range: 0.07–0.38 mm) in the center of the sleeve top, 0.24 mm (range: 0.08–0.36 mm) in the center of the sleeve bases and a mean angular deviation of 1.5° (range: 0.4°–3.3°) compared with the virtual positions. Conclusions A high accuracy can be achieved using printed templates for guided implant surgery, by taking into account all sources of inaccuracies.BACKGROUND Printing of templates for guided surgery represents an alternative to laboratory manufactured templates. PURPOSE To determine the technical accuracy of a virtually designed and printed surgical template for guided implant surgery based on a surface scan of a cast model using the coDiagnostiX™ software. MATERIALS AND METHODS Cast models and the virtual planning data of nine patients receiving guided implant surgery with the coDiagnostiX software were analyzed. The original cast models were equipped with three titanium pins and scanned with a three-dimensional scanner. The scans were uploaded in the coDiagnostiX software and the virtual surgical templates were designed including the sleeves at their original positions. After printing the surgical templates, the sleeve positions were determined by optical scanning, and deviations were calculated and compared with the virtual positions of the sleeves. RESULTS The sleeves showed a mean three-dimensional deviation of 0.22 mm (range: 0.07-0.38 mm) in the center of the sleeve top, 0.24 mm (range: 0.08-0.36 mm) in the center of the sleeve bases and a mean angular deviation of 1.5° (range: 0.4°-3.3°) compared with the virtual positions. CONCLUSIONS A high accuracy can be achieved using printed templates for guided implant surgery, by taking into account all sources of inaccuracies.

Clinical evaluation of a modified marginal sulcular incision technique in endodontic surgery.

The authors evaluated periodontal parameters following apical surgery using a new marginal sulcular incision. In 65 cases, surgical access was achieved by means of a sulcular incision technique without the involvement of the adjacent periodontia and the interproximal papillae and in 33 cases by means of a submarginal trapezoidal technique. Periodontal parameters (probing pocket depth, gingival recession, clinical attachment loss, and tooth mobility [periotest]) were recorded at baseline and after 6 months. Scar formation and the loss of papilla height were evaluated photographically. No significant changes in the attachment level and no loss of papilla height were found in either group. A slight gingival recession (0.2 +/- 0.4 mm) corresponding to the decrease in pocket depths occurred on the buccal aspect with the sulcular incision. Tooth mobility was significantly increased in both groups immediately and 6 months after surgery. Scar formation was more unfavorable with the submarginal incision.

Microguided Endodontics: Accuracy of a Miniaturized Technique for Apically Extended Access Cavity Preparation in Anterior Teeth

Introduction: The aim of this study was to assess the accuracy of guided endodontics in mandibular anterior teeth by using miniaturized instruments. This technique is designed to treat teeth with pulp canal calcifications and narrow roots by using a printed template that guides a bur to the calcified root canal. Methods: Sixty sound mandibular anterior teeth were used in 10 mandibular models. Preoperative surface and cone‐beam computed tomography scans were matched by using the coDiagnostix software. Virtual planning was performed for the access cavities, and templates were used for guidance. The templates were produced by a three‐dimensional printer. Two operators performed the access cavities. A postoperative cone‐beam computed tomography scan was superimposed on the virtual plan, and the deviation was measured in 3 dimensions and angles. Descriptive statistical analyses were performed, and 95% confidence intervals were calculated for both operators and each measured aspect. Results: The deviations between the planned‐ and prepared‐access cavities were low, with means ranging from 0.12 to 0.13 mm for different aspects at the base of the bur and 0.12 to 0.34 mm at the tip of the bur. The mean of angle deviation was 1.59°. A considerable overlap of the 95% confidence intervals indicated no significant difference between the operators. The mean treatment time, including planning and preparation, was approximately 10 minutes per tooth. Conclusions: Microguided endodontics provides an accurate, fast, and operator‐independent technique for the preparation of apically extended access cavities in teeth with narrow roots such as mandibular incisors. HIGHLIGHTSDescription of a novel treatment approach for teeth with pulp canal calcification.Microguided endodontics is accurate and operator independent.Mean treatment time, including planning, was approximately 10 minutes per tooth.

Accuracy of Three-Dimensional Printed Templates for Guided Implant Placement Based on Matching a Surface Scan with CBCT

BACKGROUND Reference elements are necessary to transfer a virtual planning into reality for guided implant placement. New systems allow matching optical scans with three-dimensional radiographic images. PURPOSE To test whether digitally designed three-dimensional printed templates (D-temp) fabricated by matching surface scans and cone beam computed tomography (CBCT) images differ from the templates fabricated in-lab (L-temp) by using a physical transfer device for the positioning of the guiding sleeves. MATERIALS AND METHODS L-temp were fabricated for eight human lower cadaver-jaws applying a digital planning software program (smop, Swissmeda AG, Zürich, Switzerland) using a Lego® (Lego Group, KIRKBI A/S, Billund, Denmark) brick as reference element and the respective transfer device (X1-table). Additionally, digital templates (D-temp) using the identical planning data sets and software were virtually designed and three-dimensional printed, after matching a surface scan with CBCT data. The accuracy of both templates for each planning was evaluated determining the estimated coronal, apical, and angular deviation if templates were used for implant placement. RESULTS Mean coronal deviations for L-temp were 0.31 mm (mesial/distal), 0.32 mm (lingual/buccal), and 0.16 mm and 0.23 mm for D-temp, respectively. The mean apical deviations for L-temp were 0.50 mm (mesial/distal), 0.50 mm (lingual/buccal). and 0.25 mm and 0.34 mm for the D-temp, respectively. Differences between both devices were statistically significant (p < .05). CONCLUSIONS A higher accuracy of implant placement can be achieved by using three-dimensional printed templates produced by matching a surface scan and CBCT as compared with templates which use physical elements transferring the virtual planning into reality.