Marcus Stoetzer

Template-guided vs. non-guided drilling in site preparation of dental implants

ObjectivesClinical success of oral implants is related to primary stability and osseointegration. These parameters are associated with delicate surgical techniques. We herein studied whether template-guided drilling has a significant influence on drillholes diameter and accuracy in an in vitro model.Materials and methodsFresh cadaveric porcine mandibles were used for drilling experiments of four experimental groups. Each group consisted of three operators, comparing guide templates for drilling with free-handed procedure. Operators without surgical knowledge were grouped together, contrasting highly experienced oral surgeons in other groups. A total of 180 drilling actions were performed, and diameters were recorded at multiple depth levels, with a precision measuring instrument.ResultsTemplate-guided drilling procedure improved accuracy on a very significant level in comparison with free-handed drilling operation (p ≤ 0.001). Inaccuracy of free-handed drilling became more significant in relation to measurement depth. High homogenic uniformity of template-guided drillholes was significantly stronger than unguided drilling operations by highly experienced oral surgeons (p ≤ 0.001).ConclusionTemplate-guided drilling procedure leads to significantly enhanced accuracy. Significant results compared to free-handed drilling actions were achieved, irrespective of the clinical experience level of the operator.Clinical relevanceTemplate-guided drilling procedures lead to a more predictable clinical diameter. It shows that any set of instruments has to be carefully chosen to match the specific implant system. The current in vitro study is implicating an improvement of implant bed preparation but needs to be confirmed in clinical studies.

Reconstruction of defects of maxillary sinus wall after removal of a huge odontogenic lesion using prebended 3D titanium-mesh and CAD/CAM technique

A 63 year-old male with a huge odontogenic lesion of sinus maxillaris was treated with computer-assisted surgery. After resection of the odontogenic lesion, the sinus wall was reconstructed with a prebended 3D titanium-mesh using CAD/CAM technique. This work provides a new treatment device for maxillary reconstruction via rapid prototyping procedures.

Advances in assessing the volume of odontogenic cysts and tumors in the mandible: a retrospective clinical trial

PurposeTo compare two methods of creating three-dimensional representations of mandibular cysts and tumors on the basis of computed tomography (CT) and cone beam computed tomography (CBCT) data.MethodsA total of 71 patients with acquired jaw cysts took part in this retrospective clinical study. CT and CBCT scans were obtained from all patients and saved in the Digital Imaging and Communications in Medicine (DICOM) format. Data were analyzed twice with iPlan software. Analysis was performed manually and using an interpolarization algorithm. The accuracy of the two methods in assessing cyst volume was compared.ResultsManual delineation did not provide more accurate results than the interpolarization algorithm.ConclusionThere are no major differences between manual analysis and analysis using the interpolarization algorithm. The use of the algorithm, however, has the advantage of rapidity.

Management of comminuted but continuous mandible defects after gunshot injuries.

INTRODUCTION Firearm injuries continue as a major public health problem, contributing significant morbidity, mortality, and expense to our society. There are four main steps in the management of patients with gunshot wounds to the face: securing an airway, controlling haemorrhage, identifying other injuries and definitive repair of the traumatic facial deformities. The objective of this study was to determine late outcome of two treatment options by open reduction and internal fixation versus closed reduction and maxillomandibular fixation (MMF) in the treatment of gunshot injuries of the mandible. METHODS Sixty patients of gunshot injury were randomly allocated in two groups. In group A, 30 patients were treated by open reduction and internal fixation and in group B, 30 patients were treated by closed reduction and maxillomandibular fixation. Patients were discharged as the treatment completed and recalled for follow up. Up to 3 months after injury, fortnightly complications like infection, malocclusion, malunion of fractured fragments, facial asymmetry, sequestration of bone and exposed plates were evaluated and the differences between two groups were assessed. The follow-up period ranged from 3 months to 10 months. RESULTS Patients treated by open reduction tended to have less complications as compared to closed reduction. CONCLUSION Based on this study open reduction and internal fixation is the best available method for the treatment of gunshot mandible fractures without continuity defect.

Effects of a new piezoelectric device on periosteal microcirculation after subperiosteal preparation.

INTRODUCTION Subperiosteal preparation using a periosteal elevator leads to disturbances of local periosteal microcirculation. Soft-tissue damage can usually be considerably reduced using piezoelectric technology. For this reason, we investigated the effects of a novel piezoelectric device on local periosteal microcirculation and compared this approach with the conventional preparation of the periosteum using a periosteal elevator. MATERIAL AND METHODS A total of 20 Lewis rats were randomly assigned to one of two groups. Subperiosteal preparation was performed using either a piezoelectric device or a periosteal elevator. Intravital microscopy was performed immediately after the procedure as well as three and eight days postoperatively. Statistical analysis of microcirculatory parameters was performed offline using analysis of variance (ANOVA) on ranks (p<0.05). RESULTS At all time points investigated, intravital microscopy demonstrated significantly higher levels of periosteal perfusion in the group of rats that underwent piezosurgery than in the group of rats that underwent treatment with a periosteal elevator. CONCLUSION The use of a piezoelectric device for subperiosteal preparation is associated with better periosteal microcirculation than the use of a conventional periosteal elevator. As a result, piezoelectric devices can be expected to have a positive effect on bone metabolism.

Designing the ideal model for assessment of wound contamination after gunshot injuries: a comparative experimental study

BackgroundModern high-velocity projectiles produce temporary cavities and can thus cause extensive tissue destruction along the bullet path. It is still unclear whether gelatin blocks, which are used as a well-accepted tissue simulant, allow the effects of projectiles to be adequately investigated and how these effects are influenced by caliber size.MethodBarium titanate particles were distributed throughout a test chamber for an assessment of wound contamination. We fired .22-caliber Magnum bullets first into gelatin blocks and then into porcine hind limbs placed behind the chamber. Two other types of bullets (.222-caliber bullets and 6.5 × 57 mm cartridges) were then shot into porcine hind limbs. Permanent and temporary wound cavities as well as the spatial distribution of barium titanate particles in relation to the bullet path were evaluated radiologically.ResultsA comparison of the gelatin blocks and hind limbs showed significant differences (p < 0.05) in the mean results for all parameters. There were significant differences between the bullets of different calibers in the depth to which barium titanate particles penetrated the porcine hind limbs. Almost no particles, however, were found at a penetration depth of 10 cm or more. By contrast, gas cavities were detected along the entire bullet path.ConclusionGelatin is only of limited value for evaluating the path of high-velocity projectiles and the contamination of wounds by exogenous particles. There is a direct relationship between the presence of gas cavities in the tissue along the bullet path and caliber size. These cavities, however, are only mildly contaminated by exogenous particles.

Nonradiological Method for 3-dimensional Implant Position Assessment Using an Intraoral Scan: New Method for Postoperative Implant Control

Introduction: This study presents a method to verify the position of dental implants after insertion without the repeated x-ray exposure. Material and Methods: An implant was inserted into the natural gap between the canines and premolars of 8 domestic pigs and 1 human patient. A scanbody was then connected to the implants and a digital intraoral impression of the jaw segment was acquired using a handheld scanner. In addition, the implant position was radiologically detected by cone beam computed tomography. The position of the implant based on both techniques was compared by digital matching. Results: The position of the dental implants determined by the scanner accurately represents the position in the radiograph in the pigs and also in the human patient. Conclusion: Evaluating the position of implants using intraoral scans is a straightforward, accurate, and radiation-free method of 3-dimensional implant position determination.

Non-radiological method for three-dimensional implant position evaluation using an intraoral scan method.

INTRODUCTION This technical innovation presents a method that reproduces the position of a dental implant after insertion without the reuse of X-ray radiation. MATERIAL AND METHODS An implant was inserted into the natural gap between the canines and premolars of three domestic pigs. A Straumann Scanbody was then screwed to the implant, and a digital impression of the jaw segment was made. The scanbody was scanned using a hand-held scanner. This was followed by the radiological detection of implant position on a CBCT. On the computer, the position of the implant was calculated and compared with the radiologically detected position. RESULTS The calculated and determined position of the dental implant by the scanner is in good agreement with the radiologically controlled position. DISCUSSION Evaluating the position of implants using intraoral scans is an easy and radiation-free method of three-dimensional site assessment after superimposition over a three-dimensional data set.

In Vitro Effects of External Pressure Changes on the Sealing Ability under Simulated Diving Conditions

Aim. To measure and validate the permeability of pressure changes in correlation to different root filling techniques. Methods. Eighty extracted single-rooted teeth were randomly assigned to one of eight groups of ten teeth. Following standardized instrumentation and irrigation, root canal fillings were performed using either cold lateral condensation, a warm carrier-based gutta-percha obturation technique, a warm carrier-based Resilon, or warm gutta-percha compaction with the downpack/backfill technique. After insertion of a pressure sensor within the pulp chamber ten teeth of each group then underwent simulated dives with pressure measurement and the other ten a dye penetration test during simulated dives to 5.0 bar. Differences were analyzed statistically (P < 0.05) using one-way analysis of variance (ANOVA). Results. When the warm carrier-based gutta-percha obturation technique and vertical gutta-percha obturation techniques were used, there was significant lower intrapulpal pressure to experimental chamber pressure (P > 0.05). When cold lateral condensation or carrier-based Resilon as used, pressure was sometimes almost completely equalized. Conclusions. Warm gutta-percha obturation techniques provide a largely pressure-tight seal whereas the Resilon obturation technique and cold lateral condensation appear to be unsuitable to pressure changes.

Pathophysiology of barodontalgia: a case report and review of the literature.

Changes in ambient pressure occur during flying, diving, or hyperbaric oxygen therapy and can cause different types of pathophysiological conditions and pain including toothache (barodontalgia). We report the case of a patient with severe pain in the region of his mandibular left first molar, which had been satisfactorily restored with a conservative restoration. Pain occurred during an airplane flight and persisted after landing. Radiology revealed a periapical radiolucency in the region of the distal root apex. Pain relief was achieved only after endodontic treatment. On the basis of this paper, we investigated the aetiology and management of barodontalgia. Dentists should advise patients to avoid exposure to pressure changes until all necessary surgical, conservative, and prosthetic procedures have been completed. The influence of pressure divergences should be noted at any time. Under changed environment pressures may be the changing perception of pathologies.