Karl Dula

Lateral ridge augmentation using autografts and barrier membranes: a clinical study with 40 partially edentulous patients.

PURPOSE This study evaluated predictability and treatment outcome of the combined application of autografts and expanded-polytetrafluoroethylene (e-PTFE) membranes for lateral ridge augmentation in partially edentulous patients using a staged approach. MATERIALS AND METHODS Forty partially edentulous patients were consecutively treated. Emphasis was given to a lateral incision technique, perforation of the cortex to open the marrow cavity, stable placement of corticocancellous autografts and bone chips, precise adaptation of the e-PTFE membranes and stabilization with miniscrews, and a tension-free primary soft tissue closure. After 7 to 13 months, the sites were reopened for membrane removal and implant placement. RESULTS All but one patient showed complication-free soft tissue healing. After reopening, 38 patients exhibited excellent ridge augmentation, whereas two had compromised results, with soft tissue encapsulation of some bone chips. None of the applied block grafts showed clinical signs of resorption. Preaugmentation and postaugmentation measurements showed an enlargement of the crest width from a mean of 3.5 mm to 7.1 mm. This allowed the placement of nonsubmerged titanium implants in all 40 patients. CONCLUSIONS The current study demonstrates that the combined application of autografts and e-PTFE membranes is a predictable surgical procedure for lateral ridge augmentation that results in an enlargement of the alveolar crest in partially edentulous patients. The autografts support the membrane and activate bone formation with their osteoconductive and osteoinductive properties. The membrane acts as a physical barrier to nonosteogenic soft tissue cells, and protects the autografts against resorption during healing.

Comparison of periapical radiography and limited cone-beam tomography in posterior maxillary teeth referred for apical surgery

This study compared periapical (PA) radiography and cone-beam tomography (CBT) for preoperative diagnosis in posterior maxillary teeth of consecutive patients referred for possible apical surgery. Images were concurrently analyzed by an oral radiologist and an endodontist to reach consensus in interpretation of the radiographic findings. The final material included 37 premolars and 37 molars with a total of 156 roots. CBT showed significantly more lesions (34%, p < 0.001) than PA radiography. Detecting lesions with PA radiography alone was most difficult in second molars or in roots in close proximity to the maxillary sinus floor. Additional findings were seen significantly more frequently in CBT compared with PA radiography including expansion of lesions into the maxillary sinus (p < 0.001), sinus membrane thickening (p < 0.001), and missed canals (p < 0.05). The present study highlights the advantages of using CBT for preoperative treatment planning in maxillary posterior teeth with apical pathology.

Clinical experience with one-stage, non-submerged dental implants.

This review article describes the scientific documentation of one-stage, non-submerged dental implants. In the past 25 years, numerous in vivo studies have demonstrated that non-submerged titanium implants achieve osseointegration as predictable as that of submerged titanium implants. This observation was confirmed in prospective clinical studies, mostly done with the ITI® Dental Implant System. ITI implants have been widely documented for up to 10 years of prospective follow-up at various centers. All studies showed success rates well above 90%. In summary, the non-submerged approach is a true alternative to the original healing modality with submerged titanium implants. The non-submerged approach offers several clinical advantages: (i) the avoidance of a second surgical procedure and less chair time per patient, resulting in overall reduced treatment cost; (ii) the lack of a microgap at the bone crest level, leading to less crestal bone during healing and resulting in a more favorable crown-to-implant length ratio; and (iii) a simplified prosthetic procedure, presenting an ideal basis for cemented implant restorations. Due to these significant clinical advantages, the non-submerged approach will become more important in implant dentistry in the near future, particularly in implant sites without esthetic priority.

Effects of dose reduction on the detectability of standardized radiolucent lesions in digital panoramic radiography

Dose reduction in digital panoramic radiography was studied. Intentional underexposure was performed with the Orthophos DS while six different human mandibles were radiographed. Exposure settings were 69 kV/15 mA (standard), 64 kV/16 mA, and 60 kV/16 mA. Standardized spherical defects, each either 1 or 1.25 mm in diameter, were simulated in 288 of 432 images, and seven observers decided whether defects were present or not. Areas under the receiver operating characteristics curves were calculated. They showed no significant differences in the detectability of the 1-mm defect at 69, 64, or 60 kV. For the 1.25-mm defect, no difference was found between the 69 and 60 kV images, but a statistically significant different detectability was found for 64 kV images in comparison with both 69 and 60 kV images. A dose reduction of up to 43% was ascertained with a Pedo-RT-Humanoid phantom when panoramic radiography was performed at 60 kV/16 mA. The conclusion is that with the Orthophos DS, it seems possible to reduce the dose rate of x-rays without loss of diagnostic quality in the case of radiolucent changes.

Diagnosis of tooth ankylosis using panoramic views, cone beam computed tomography, and histological data: a retrospective observational case series study

Objectives The aim of this study was to determine whether cone beam computed tomography is a reliable radiological method to diagnose tooth ankylosis. Materials and methods A series of teeth clinically diagnosed as ankylosed were collected after extraction in a private practice from 2009 to 2015 and analyzed retrospectively. Inclusion criteria comprised permanent molars extracted due to failed tooth eruption in the absence of any visible mechanical obstruction, existing panoramic view (PV), and cone beam computed tomography (CBCT) and histological sections of sufficient quality. The CBCT scans and PVs were evaluated twice for signs of ankylosis by two independent observers using the following score: clear signs, possible signs, and no signs. The histological sections were evaluated and graded similarly to the radiographs by a specialist blinded to the radiographs and treatment. Results Out of an initial group of 22 patients, 9 subjects with 10 affected teeth were included for final evaluation. The age ranged from 8.3 to 17 years. No agreement was seen in comparing the PV scores to the histological sections. Fair to moderate agreement was seen in comparing the CBCT scores to the histological sections. All histologically confirmed ankylosis were detected in CBCT by both observers but some false positive results were found. Limitation Only a small sample size was available as the disorder is rare. It is difficult to distinguish ankylosis from primary failure of eruption. Conclusion CBCT images can be a useful adjunctive diagnostic tool to diagnose ankylosed teeth, but cannot be recommended as a single diagnostic modality as false positive results were found.