Gabriel Krastl

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.

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.

Resin-bonded restorations: a strategy for managing anterior tooth loss in adolescence

In children or adolescents with anterior tooth loss, space closure with the patients own teeth should be considered as the first choice to avoid lifelong restorative needs. Thorough diagnostics and treatment planning are required when autotransplantation or orthodontic space closure is considered. If these options are not indicated and a single tooth implant restoration is considered, implant placement should be postponed until adulthood, particularly in young women and in patients with hyperdivergent skeletal growth pattern. A ceramic resin-bonded fixed dental prosthesis with 1 retainer is an excellent treatment solution for the interim period; it may also serve as a long-term restoration, providing that sound enamel structure is present, sufficient framework dimensions have been provided, adhesive cementation techniques have been meticulously applied, and functional contacts of the cantilever pontic avoided. In contrast, a resin-bonded fixed dental prosthesis with a metal framework and retentive preparation is indicated if the palatal enamel structure is compromised, interocclusal clearance is limited, splinting (such as after orthodontic treatment) is required, or more than 1 tooth has to be replaced.

Accuracy of a separating foil impression using a novel polyolefin foil compared to a custom tray and a stock tray technique

PURPOSE To compare the dimensional accuracy of three impression techniques- a separating foil impression, a custom tray impression, and a stock tray impression. MATERIALS AND METHODS A machined mandibular complete-arch metal model with special modifications served as a master cast. Three different impression techniques (n = 6 in each group) were performed with addition-cured silicon materials: i) putty-wash technique with a prefabricated metal tray (MET) using putty and regular body, ii) single-phase impression with custom tray (CUS) using regular body material, and iii) two-stage technique with stock metal tray (SEP) using putty with a separating foil and regular body material. All impressions were poured with epoxy resin. Six different distances (four intra-abutment and two inter-abutment distances) were gauged on the metal master model and on the casts with a microscope in combination with calibrated measuring software. The differences of the evaluated distances between the reference and the three test groups were calculated and expressed as mean (± SD). Additionally, the 95% confidence intervals were calculated and significant differences between the experimental groups were assumed when confidence intervals did not overlap. RESULTS Dimensional changes compared to reference values varied between -74.01 and 32.57 µm (MET), -78.86 and 30.84 (CUS), and between -92.20 and 30.98 (SEP). For the intra-abutment distances, no significant differences among the experimental groups were detected. CUS showed a significantly higher dimensional accuracy for the inter-abutment distances with -0.02 and -0.08 percentage deviation compared to MET and SEP. CONCLUSION The separation foil technique is a simple alternative to the custom tray technique for single tooth restorations, while limitations may exist for extended restorations with multiple abutment teeth.