Paul A. Schnitman

Histopathology of Oral Endosteal Metallic Implants in Dogs

Four weeks after implantation of oral endosteal metallic implants, acute inflammatory responses of the gingiva were observed. By eight weeks, the inflammation was transitional to chronic. Bony degeneration was noted eight months after implantation. No epithelial or fibrous connective tissue adherence or attachment to the blades was evident.

Dental Implants: State of the Art, State of the Science

Analysis of epidemiologic studies reveals that even with advances in preventive dentistry, edentulism continues to be a pressing problem especially in a rapidly expanding senior population. As an alternative to traditional removable dentures, dental implants can provide fixed support for crowns and bridges. A recent National Institutes of Health Consensus Development Conference revealed significant growth in implant technology and established that, although a complex treatment alternative, implants can function for 10 years or more. Continued development in basic and clinical research, federal regulations, professional education, public awareness, insurance, and marketing will shape the future of the field.

Why Guided When Freehand Is Easier, Quicker, and Less Costly?

Computer-assisted implant planning and subsequent production of a surgical template based on this plan has gained attention because it provides restoratively driven esthetics, patient comfort, satisfaction, and the option of flapless surgery and immediate restoration. However, it adds expense and requires more time. Another significant but not so apparent advantage may be improved survival and success over freehand techniques in types III and IV bone. This retrospective analysis was undertaken to examine that possibility. It reports 1-year outcome for 80 implants in 27 consecutively presenting patients treated over a 7-year period using computer-assisted techniques across all bone qualities in commonly encountered treatment indications in private practice. Implants were placed to support single teeth, small bridges, and complete arch restorations in exposed or immediately restored applications, based on primary stability as determined by insertion torque, resonance frequency analysis, and Periotest. For the 80 implants supporting 35 restorations, the median observation period is 2.66 years; 73 implants supporting prostheses in 22 patients had readable radiographs at 1 year. There was a 1-year overall implant survival and a success rate of 100%. Radiographic analysis demonstrated the change in bone level from the platform at 1-year is less than 2 mm. Intra-operative median measurements of primary stability were insertion torque, 40 Ncm; resonance frequency, 76 ISQ; and Periotest, -3. All intra-operative measurements were consistent for acceptable primary stability regardless of bone density. Restoratively driven diagnosis and precision planning and initial fit were possible with computer-assisted techniques resulting in the achievement of high primary stability, even in areas of less dense bone. The ability to plan implant position, drill sequence, and implant design on the basis of predetermined bone density gives the practitioner enhanced pretreatment information which can lead to improved outcome.

Completely Digital Two-Visit Immediately Loaded Implants: Proof of Concept.

Implant dentistry has become a common treatment alternative, yet only a small percentage of patients missing teeth are receiving its benefits. Significant limitations are the small percent of practitioners placing implants due to the long learning curve, as well as the time commitment on the part of the patient. This proof of concept demonstrates clinical implant treatment requiring years of manual skill development on the part of the surgeon, restorative dentist, and technician can be accomplished in 2 visits, completely digitally, without the need for conventional impressions, laboratory procedures, and advanced manual skills. This technique results in reduced learning curve and treatment time. The first visit consists of consultation, diagnosis, CT and optical surface scans of the implant site to include: soft tissue, adjacent teeth, and opposing arch. This digital information is imported and interactively reconstructed in a 3-D open format implant planning software. The implant and restoration are now precisely planned into the optimal bone position with the ideal emergence profile for biologically and esthetically designed restoration. This information is then electronically forwarded to a production facility, where all necessary models are digitally printed and the immediate crown is digitally milled. On the second visit, the patient returns for guided implant insertion and immediate restoration. As digital procedures are refined, many more dental professionals will become involved in providing implant therapy earlier in their careers. This promises to result in reduced costs, making implants available to millions more patients who could benefit from them.

Guided flapless surgery with immediate loading for the high narrow ridge without grafting.

Computer guided implant treatment allows implants and associated restorations to be precisely placed during the same procedure directly through the gingiva with reduced postoperative complications and surgical time. When bone height is adequate but very narrow, the virtual guided sleeve is often placed too deeply into the ridge crest interfering with the seating of the surgical template. This case report of a patient exhibiting very narrow residual ridges due to severe resorption describes a new computer guided procedure using a single surgical template maintaining bone height and immediate restoration without a mucoperiosteal flap. The success of this technique is the result of innovative modifications in the software as well as instrumentation. Modifications include planning a different implant length virtually to raise the position of guide sleeves, alteration of drilling sequences, modifications of the start drill, incorporation of osteotomes, and use of an alternative implant seating mount. The combination of these methods allows for deeper site preparation and implant seating beyond the default settings, without any crestal bone reduction. These modifications not only make the guided concept possible for the entire preparation and seating procedures, but also allow for the slight removal of bone that would interfere with the implant seating through the surgical template without a mucoperiosteal flap. This new approach to computer guided surgery maintains prosthetic precision in the fabrication of a provisional restoration prior to implantation with minimal delivery adjustments using prefabricated conical abutments when placing implants at differing levels into the high narrow ridge.

Bone maintenance: implant versus transplant.

Bone maintenance based on various attachment mechanisms is the key to tooth-root replacement safety and efficacy. The dental implant has broad applicability based on design, but demonstrates progressive peri-implant bone loss. The allogeneic tooth transplant, significantly less applicable because of size, is antigenic and rejected by bone-replacement root resorption. Since the predictability and survival times of these implant and transplant modalities are similar and there is less residual bone loss with the transplant, it is suggested that for clinical situations such as the fresh extraction socket, where there is room, the allotransplant, rather than implant, is the root-replacement of choice.

Papilla Formation in Response to Computer-Assisted Implant Surgery and Immediate Restoration

This retrospective analysis was undertaken to evaluate the effect of immediate implant restoration using a computer-assisted technique in partially edentulous sites on interimplant and intertooth bone level stability and papilla formation. Nine partially edentulous patients received a total of 23 implants that supported immediately placed implant restorations. Planning was accomplished using a radiographic guide, which allowed visualization of the emergence profile from the platform of the implant to the cervical of the planned restoration. Guided implants were placed according to the manufacturers instructions, and restorations were screw retained directly to the implant. Multiple implants were splinted at surgery with autopolymerizing resin. Measurements were made at a mean of 545 days (range 288-958) postoperatively on the basis of radiographs and photographs. Measures were: (1) distance from bone crest to platform, (2) bone crest to contact point, (3) interimplant distance at the outer diameter of the platform, and (4) papilla from highest point to a reference line. At follow-up time, the bone ridge was located higher than the implant platform (mean 0.57 mm) compared to implants whose interimplant distance was less than 3 mm (mean 0.27 mm). Mean increase of the bone level between insertion and approximate 1-year follow-up was 0.047 mm. The mean distance from the contact point to bone was 2.39/3.93 mm postoperatively, resulting in 91/71% papilla fill between implants and between implant and adjacent tooth, respectively. Computer-assisted surgery with the preplanned immediate restoration seems to be an effective method to minimize bone loss at the implant platform resulting in support for papilla.