Palatal bone support for orthodontic implant anchorage--a clinical and radiological study.
When maximal anchorage is required during orthodontic treatment, additional aids are often needed to support the anchoring teeth. While intra-oral aids may be limited in their anchorage potential, extra-oral anchoring aids are often rejected by the patients. Endosseous implants may therefore be a valuable alternative for stable intra-oral anchorage. However, the possibility of using conventional implants is insufficient, e.g. for treating purely orthodontic patients with full dentition or where extraction sites are to be closed. Therefore, the mid-sagittal area of the palate is an alternative insertion site for the placement of implants for orthodontic anchorage. The limited bone height in this area inspired this comparison between bone thickness in the implantation site as verified by probing during the implantation of Straumann Ortho-system implants, and thickness as measured on the lateral cephalogram. The results suggest that vertical bone support is at least 2 mm higher than apparent on the cephalogram. In none of 12 patients was a perforation to the nasal cavity found. However, in five subjects the implant projected into the nasal cavity on the post-operative cephalogram. These results were supported by the study of the projections of palate and wires in wire-marked skulls where the wires were placed bilaterally on the nasal floor and on the nasal crest. It is therefore concluded that the mid-sagittal area of the palate lends sufficient bony support for the implantation of small implants (4-6 mm endosseous length, diameter 3.3 mm). (+info)
Bone response to orthodontic loading of endosseous implants in the rabbit calvaria: early continuous distalizing forces.
The purpose of this experimental study was to evaluate the effect of early orthodontic loading on the stability and bone-implant interface of titanium implants in a rabbit model. Twenty-four short threaded titanium fixtures were inserted in the calvarial mid-sagittal suture of 10 rabbits. Two weeks following insertion, 20 implants (test group) were subjected to continuous distalization forces of 150 g for a period of 8 weeks. The remaining four implants (control group) were left unloaded for the same follow-up interval. Clinically, all implants except for one test fixture were stable, and exhibited no mobility or displacement throughout the experimental loading period. Histologically, all stable implants were well-integrated into bone. No differences could be found between the pressure and tension surfaces of the test implants relative to bone quality and density within a range of 1000 microns from the fixture surface. Similarly, qualitative differences were not observed between the apical and coronal portions of test fixtures. Morphometrically, a mean percentage bone-to-implant contact of 76.00 +/- 18.73 per cent was found at the test pressure sides, 75.00 +/- 11.54 per cent at the test tension sides, and 68.00 +/- 15.55 per cent at the control unloaded surfaces. No statistically significant differences in the percentage of bone-to-metal contact length fraction were found between test pressure surfaces, test tension surfaces, and unloaded control surfaces. Marginal bone resorption around the implant collar or immediately beneath it was found in roughly the same percentage of analysed sites in the test and control fixtures. In contrast, slight bone apposition was demonstrated at the implant collar of the test pressure surfaces, while no apposition or resorption were observed in the test tension zones. This study suggests that short endosseous implants can be used as anchoring units for orthodontic tooth movement early in the post-insertion healing period. (+info)
The Procera abutment--the fifth generation abutment for dental implants.
The Branemark dental implant has undergone progressive development in terms of both the implant body itself and the components connecting the implant to the prosthesis. Many screw and abutment designs have been developed, with various degrees of success. About 15 years ago, CAD (computer-assisted design)-CAM (computer-assisted manufacture) technology was introduced to dentists. More recently CAD-CAM has been used in the manufacture of abutments for implants. This article reviews currently available techniques for creating the Procera custom abutment (Nobel Biocare, Goteborg, Sweden) and outlines appropriate applications for this type of implant. (+info)
Surgical simulation of Class III edentulous patient using a 3D craniofacial model: report of a case.
A case of edentulous prognathism in a 46-year-old Japanese male is presented. We described the outcome of the patient who underwent simultaneous sagittal splitting ramus osteotomy of the edentulous mandible, interpositional bone graft of severely atrophic edentulous jaws, and delayed placement of titanium implants for reconstruction. We highly recommend performing a surgical simulation using a craniofacial model of the patient's anatomy created using CT image data. The procedure provides almost ideal maxillary and mandibular contours. (+info)
C-telopeptide pyridinoline cross-links (ICTP) and periodontal pathogens associated with endosseous oral implants.
Detection of periodontal or peri-implant sites exhibiting progressing disease or those at risk of deterioration has proven difficult. Pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), a marker specific for bone degradation found in gingival crevicular fluid (GCF), has been associated with both bone and attachment loss in periodontitis and may be useful for predicting disease activity. The aim of this cross-sectional study was to examine the relationship between ICTP levels and subgingival species around implants and teeth from 20 partially and 2 fully edentulous patients. GCF and plaque samples were collected from the mesiobuccal site of each implant and tooth. Radioimmunoassay techniques were utilized to determine GCF ICTP levels. Plaque samples were analyzed utilizing checkerboard DNA-DNA hybridization. Traditional clinical parameters were assessed. Seventy-one implants and 370 teeth from 22 subjects were examined. ICTP levels and subgingival plaque composition were not significantly different between implants and teeth. Implant sites colonized by Prevotella intermedia, Capnocytophaga gingivalis, Fusobacterium nucleatum ss vincentii, and Streptococcus gordonii exhibited odds ratios of 12.4, 9.3, 8.1, and 6.7, respectively of detecting ICTP. These results suggest a relationship between elevated ICTP levels at implant sites and some species associated with disease progression. Longitudinal studies are necessary to determine whether elevated ICTP levels may predict the development of peri-implant bone loss. (+info)
Changing paradigms in implant dentistry.
This review focuses on five paradigms of implant dentistry which have undergone considerable modifications in recent years. An attempt was made to select and include all the relevant citations of the past 10 years. These five paradigms document the debate in the clinical and scientific community and include the aspects of (1) smooth vs. rough implant surfaces, (2) submerged vs. non-submerged implant installation techniques, (3) mixed tooth-implant vs. solely implant-supported reconstructions, (4) morse-taper abutment fixation vs. butt-joint interfaces, and (5) titanium abutments vs. esthetic abutments in clinical situations where esthetics is of primary concern. (+info)
Dental products devices; reclassification of endosseous dental implant accessories. Food and Drug Administration, HHS. Final rule.
The Food and Drug Administration (FDA) is reclassifying the manually powered drill bits, screwdrivers, countertorque devices, placement and removal tools, laboratory pieces used for fabrication of dental prosthetics, trial abutments, and other manually powered endosseous dental implant accessories from class III to class I. These devices are intended to aid in the placement or removal of endosseous dental implants and abutments, prepare the site for placement of endosseous dental implants or abutments, aid in the fitting of endosseous dental implants or abutments, aid in the fabrication of dental prosthetics, and be used as an accessory with endosseous dental implants when tissue contact will last less than an hour. FDA is also exempting these devices from premarket notification. This reclassification is on the Secretary of Health and Human Services' own initiative based on new information. This action is being taken under the Federal Food, Drug, and Cosmetic Act (the act), as amended by the Medical Device Amendments of 1976 (the 1976 amendments), the Safe Medical Devices Act of 1990 (the SMDA), and the Food and Drug Administration Modernization Act of 1997 (FDAMA). (+info)
Hard palate deformation in an animal model following quasi-static loading to stimulate that of orthodontic anchorage implants.
The aim of the present investigation was to identify adequate implant treatment for young patients. In an animal model palate deformation was investigated by acute quasi-static loading. Three series of tests (with newborn, young and adult pigs) were performed, each with two groups (one or two-point stress) and 5-7 animals per group. Discs with a diameter of 3 and 5 mm were placed in group 1 in the suture area, and in group 2 at both the right and left sides of the suture. Deformation was analysed by a computerized three-dimensional (3D) photo-imaging evaluation system. In young animals the one-point load at a significantly lower force level led to fractures in comparison with the two-point load (P < 0.001). Similar results were measured by an increase in the size of one disc from 3 to 5 mm (P < 0.001). In contrast, adult pigs showed stable results with both methods. In general, a larger disc diameter led to less instability. The one-point load seems to be suitable for adult animals, whereas a two-point load might be favourable during ossification. The advantage of the two-point load is the generation of a higher stress and therefore improved control of dental fixation. However, further tests are necessary to investigate the long-term effects. (+info)