A comparative analysis of the engineering of 5 commercially available titanium dental implant surfaces using micro-focus computed tomography
International Conference on Pharmaceutical and Biomedical Engineering
Authors: Andre van Zyl, Michaela Beetge, Jacobus Hoffman, Stephan van Zyl, Vladimir Todorovic, Cor-Jacques Kat and Schalk Kok
University of Pretoria, South Africa
Introduction & Aim: The engineering of dental implant surfaces has shown tremendous development over the past decade. Bone-to-implant interface is influenced mainly by implant surface topography. The objective was to analyse the exact surface area of different implant diamters of 5 systems using micro-focus cone beam tomography. Methods: 100 implants were scanned at Necsa (South African Nuclear Energy Corporation) which houses the Nikon XTH 225 ST micro-focus CT scanner.
A micro-CT study of the greater palatine foramen in human skulls
Authors: Beetge MM1, Todorovic VS1,2,Oettlé A3, Hoffman J4, van Zyl AW1.
1 Department of Periodontics and Oral Medicine, School of Dentistry, University of Pretoria.
2 School of Dental Medicine, University of Belgrade.
3 Department of Anatomy, Faculty of Health Sciences, University of Pretoria.
4 South African Nuclear Energy Corporation.
The greater palatine foramen (GPF) is an important anatomical landmark and has substantial clinical relevance in dental surgery. Knowledge of its precise location and dimensions is required for proper planning of surgical procedures involving the posterior maxilla. We used microfocus computed tomography to determine the location and dimensions of the GPF, and any sex and race variations in those measurements, in 77 human skulls scanned at the South African Nuclear Energy Corporation. Specialized software was used for three-dimensional rendering, segmentation, and visualization of the reconstructed volume data. GPF location ranged from adjacent to the first molar to distal of the third molar. The most common GPF location was near the third molar (66.7% of skulls), and the GPF was as close as 6.31 mm (mean distance 12.75 ± 3 mm). The mean GPF dimensions were 5.22 mm on the anterior-posterior axis and 2.81 mm on the lateral-medial axis. We noted no significant differences in relation to race, sex, or age in the sample. The GPF was adjacent or posterior to the third maxillary molar in most skulls.
A retrospective analysis of maxillary sinus septa on reformatted computerised tomography scans.
Authors: van Zyl AW1, van Heerden WF.
1 Department of Periodontics and Oral Medicine, School of Dentistry, University of Pretoria, Pretoria, South Africa. email@example.com
This study analysed 200 consecutive computerised tomography (CT) scans, reformatted with specialised software for the identification of maxillary sinus septa. All patients were routine implant patients who had undergone CT scans for dental implant planning.
MATERIALS AND METHODS:
The data of two hundred consecutive patients (400 maxillary sinuses) who had been sent for CT scan, were reformatted with CT software. The group consisted of 115 edentulous and 85 dentate (below sinuses) patients. Septa were identified using three-dimensional (3D) reconstruction and panoramic views. No septa were included unless they were clearly visible on the 3D reconstruction. The prevalence, height and number of septa were analysed for both groups of patients.
Anterior Mandibular Lingual Defect As a Possible Cause of Near-Fatal Bleeding During Routine Dental Implant Surgery: A Retrospective Computed Tomography Study.
Authors: Schnetler C, Todorovic VS1, van Zyl AW2.
1 ITI Scholar, Department of Periodontics and Oral Medicine, School of Dentistry, University of Pretoria, Pretoria, South Africa.
2 Professor, Head of Department of Periodontics and Oral Medicine, School of Dentistry, University of Pretoria, Hatfield, South Africa.
The anterior mandible is generally regarded as a safe anatomical region for implant placement. However, anatomical variations may lead to severe intraoperative complications with potential fatal outcome. The objective of this study was to evaluate the anterior mandibular lingual defect (AMLD) in patients undergoing implant surgery.
Assessment of the anterior loop of the inferior alveolar nerve using reformatted computed tomography : a retrospective study
The anterior loop of the inferior alveolar nerve (IAN) is an important landmark in the anterior mandible that must be considered during the placement of dental implants. We measured the length and prevalence of loops of the IAN in 188 consecutive, dentate patients using reformatted computed tomography (CT). A total of 158/188 (84%) had at least one anterior loop; 111/188 (59%) had bilateral loops. The mean (SD) length of the loops in the third quadrant was 1.4 (0.7) mm; 95% CI 1.3 to 1.6; (range 0.3 – 4.0 mm). The mean (SD) length of the loops in the fourth quadrant was 1.5 (0.9) mm; 95% CI 1.4 to 1.6; range 0.3 – 5.5 mm. In total 42/188 (22%) had loops that were longer than 2 mm in quadrants three and four. CT images that have been reformatted with specialised software may be useful to identify loops in the IAN, particularly when recent cone-beam CT images are not freely available. The prevalence of these loops is high while their length varies, which makes meticulous assessment necessary before the placement of implants.
Prosthodontic treatment considerations and management of a frail 87-year old patient
Christiaan Vorster1 and André W. van Zyl
World-wide populations are aging at a remarkable rate. The fastest growing segment of the population in the United States is 65 years and older, and the expected increase in the number of very old people (80 years and older) is increasing in most countries. 1
The increase in the number of very old people, will translate into an increase in special care and attention to maintain a reasonable quality of life in the face of disability and growing frailty in this group. The net result is that demands for health and social services will increase substantially over the next quarter century. 2
Tooth loss has a direct influence on reduced masticatory function and a shift towards a poorly balanced diet. This in turn will not only result in an increase in oral diseases, but also a deficiency in various micronutrients, leading to a compromised immune status. This may make patients more susceptible to various infections and even cancers. 3 Download PDF
Enhanced Activity of Demineralised Bone Matrix Augmented with Xenogeneic Bone Morphogenetic Protein Complex in Rats
Author: Mohangi, Govindrau Udaibhan, Rothman, B, Van Zyl, Andre W, Duneas, Nicolaas
Demineralised bone matrix (DBM) is an allograft material widely used as a bone filler and bone graft substitute. DBM contains bone morphogenetic proteins (BMPs), which induce and regulate bone formation during embryogenesis and in postnatal life. AIMS AND OBJECTIVES: To investigate the osteoinductivity of DBM augmented with xenogeneic BMP-complex at different doses. MATERIALS AND METHODS: Rat DBM was augmented with BMP-complex purified from porcine diaphyseal bone. RESULTS: Dorsal subcutaneous implantation of 25 mg rat allogeneic DBM augmented with 0, 3, 6 and 12 mg BMPcomplex per gram of DBM resulted in dose dependant upregulation of bone formation on day 21, as scored histologically and biochemically. CONCLUSIONS: Allogeneic DBM can be augmented with xenogeneically sourced BMP-complex to improve DBM performance in vivo. This work demonstrates the potential of BMP-complex augmented DBM to induce new bone formation with improved parameters of bone formation.
Stability Development of Immediately Loaded Hybrid Self-Tapping Implants Inserted in the Posterior Maxilla: 1-Year Results of a Randomized Controlled Trial
Author: Vladimir S. Todorovic, MSc, Miroslav Vasovic, DDS, Mia-Michaela Beetge, MChD, Andre W. van Zyl, MChD, Vladimir Kokovic, PhD
The objective of the present study was to elucidate stability development of immediately loaded hybrid self-tapping implants inserted in the posterior maxilla. Forty-eight hybrid self-tapping implants with a chemically modified surface (∅4.1; length: 8 mm) were inserted bilaterally in the maxillary first and second premolar and first molar sites of 8 patients. In each patient, both sides of the maxilla were assigned randomly to either immediate (IL) or early (EL) loading group. Implant stability was evaluated by means of resonance frequency analysis immediately after implant placement and after 1, 2, 3, 4, 5, 6, 12, 26, and 52 weeks. High values of primary stability were found in both groups (71.91 ± 6.52 implant stability quotient [ISQ] in IL group; 73.87 ± 6.5 ISQ in EL group), with significant differences between the groups at the different time points. Initial decrease in stability was observed between the first and fifth weeks in the IL group and between the first and third weeks for the EL group. In the IL group 1 implant was removed after 3 weeks due to lack of stability. Early results of this study showed the ability of hybrid self-tapping dental implants with a chemically modified surface to achieve sufficient primary stability and to maintain high values of secondary implant stability in bone type 3 and 4, even when loaded immediately. Minimal alterations in stability were observed for both investigated groups, but the EL group showed faster recovery after an initial drop in stability.
Surgical reconstruction of lost papilla around implant with a modified technique: A case report
Authors: Mahdi Faraji, Andre Van Zyl
This case report describes the clinical application of the coronally advanced flap procedure associated with the subepithelial connective tissue pedicle graft with palatal tunneling for the reconstruction of interproximal papillae. In this modified technique the distal end of the pedicle graft was divided into two parts, creating a bifid, which were then placed around the abutment and sutured on the facial aspect. This technique resulted in the filling up of the entire black triangle, coverage of gingival recessions on adjacent teeth, a significant improvement in the emergence profile of the implant-supported restoration, and obvious esthetic improvement.
The Midline Mandibular Lingual Canal : importance in implant surgery
Authors: Oettle, Anna Catherina; Fourie, Jeanine; Human-Baron, René; Van Zyl, Andre W.
PURPOSE : To determine the position and occurrence of the midline mandibular canal (MLC) in the various age, sex, population and dentition groups. The average distances from the MLC to a planned mandibular midline implant and the inferior mandibular border were measured. MATERIALS AND METHODS : Cone beam computed tomography (CBCT) was used to scan 122 mandibles (31 black males; 28 black females; 32 white males and 31 white females). Midsagittal sections in the reconstructed images of edentulous mandibles or sagittal sections through the socket of the 41 tooth (FDI nomenclature) in dentate mandibles were made. A measurement of 6 mm across buccolingually (BL) was delineated with the caliper tool indicating the minimum dimensions for placement of an implant. In dentate cases where the BL distance was in excess of 6 mm, the caliper was placed across the deepest part of the socket as a marker to determine the bone dimension available below the socket for implant placement. From these markers a vertical line was dropped to the MLC to measure the available bone. RESULTS : The MLC was a consistent finding within the anterior mandible. A statistical significant difference in bone availability amongst the sexes and with dentition pattern was found indicating that edentulous female patients were particularly at risk of injury to the vessels of the midline lingual canal during implants in that area. CONCLUSION : Immediate implants in the position of lower central incisors are regarded as a safe procedure as is the placement of interforaminal implants in the anterior mandible. Clinicians should however take note of the position of the midline mandibular lingual canal and approach this area with caution, especially if the alveolar ridge is to be reduced before implant placement.
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