Specific amelogenin gene splice products have signaling effects on cells in culture and in implants in vivo.
Low molecular mass amelogenin-related polypeptides extracted from mineralized dentin have the ability to affect the differentiation pathway of embryonic muscle fibroblasts in culture and lead to the formation of mineralized matrix in in vivo implants. The objective of the present study was to determine whether the bioactive peptides could have been amelogenin protein degradation products or specific amelogenin gene splice products. Thus, the splice products were prepared, and their activities were determined in vitro and in vivo. A rat incisor tooth odontoblast pulp cDNA library was screened using probes based on the peptide amino acid sequencing data. Two specific cDNAs comprised from amelogenin gene exons 2,3,4,5,6d,7 and 2,3,5,6d, 7 were identified. The corresponding recombinant proteins, designated r[A+4] (8.1 kDa) and r[A-4] (6.9 kDa), were produced. Both peptides enhanced in vitro sulfate incorporation into proteoglycan, the induction of type II collagen, and Sox9 or Cbfa1 mRNA expression. In vivo implant assays demonstrated implant mineralization accompanied by vascularization and the presence of the bone matrix proteins, BSP and BAG-75. We postulate that during tooth development these specific amelogenin gene splice products, [A+4] and [A-4], may have a role in preodontoblast maturation. The [A+4] and [A-4] may thus be tissue-specific epithelial mesenchymal signaling molecules. (+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)
Update on immediate implant loading: a review of the literature.
The treatment of totally or partially edentulous patients with osseointegrated implants is an increasing part of daily dental practice. The greater aesthetic and functional demands made by these patients have created a constant pressure to reduce the waiting time before implants are loaded. In some cases, however, a shortening of the waiting period may compromise the osseointegration of the fixtures. The present review aims to inform the clinician about the continuing controversy on this issue. Data from the reviewed studies allow comparisons to be made between the different success rates obtained after immediate implant loading, offering a more objective basis for our advice to patients on this type of treatment. According to our review, the type and quality of the bone and the surface of the implant are the factors that determine the selection of patients who can undergo the premature loading of implants. (+info)
Implant imaging for the dentist.
Dental implants have become part of routine treatment plans in many dental offices because of their increasing popularity and acceptance by patients. Appropriate preplacement planning, in which imaging plays a pivotal role, helps to ensure a satisfactory outcome. The development of precise presurgical imaging techniques and surgical templates allows the dentist to place these implants with relative ease and predictability. This article gives an overview of current practices in implant imaging for the practising dentist, with emphasis on selection criteria. Imaging protocols for site assessment and restorative evaluation are discussed. This information will enable the dentist to select and use appropriate radiographic images (digital or film) for implant treatment planning, restoration and postoperative follow-up. Modalities presented include intraoral and panoramic projections, linear and complex motion tomography and computed tomography (CT). The use of CT image reformatting software such as Dentascan and SimPlant with 3-dimensional reconstructions is discussed. (+info)
Immediate implants after extraction. A review of the current situation.
Immediate implants are positioned in the course of surgical extraction of the tooth to be replaced. The percentage success of such procedures varies among authors from 92.7-98.0%. The main indication of immediate implantation is the replacement of teeth with pathologies not amenable to treatment. Its advantages with respect to delayed implantation include reduced post-extraction alveolar bone resorption, a shortening of the rehabilitation treatment time, and the avoidance of a second surgical intervention. The inconveniences in turn comprise a general requirement for membrane-guided bone regeneration techniques, with the associated risk of exposure and infection, and the need for mucogingival grafts to seal the socket space and/or cover the membranes. The surgical requirements for immediate implantation include extraction with the least trauma possible, preservation of the extraction socket walls and thorough alveolar curettage to eliminate all pathological material. Primary stability is an essential requirement, and is achieved with an implant exceeding the alveolar apex by 3-5 mm, or by placing an implant of greater diameter than the remnant alveolus. Esthetic emergence in the anterior zone is achieved by 1-3 mm sub-crest implantation. Regarding guided regeneration of the alveolar bone, the literature lacks consensus on the use of membranes and the type of filler material required. While primary wound closure is desirable, some authors do not consider it to be of great relevance. (+info)
Computer-assisted navigational surgery enhances safety in dental implantology.
INTRODUCTION: Dental implants are increasingly used to restore missing dentition. These titanium implants are surgically installed in the edentulous alveolar ridge and allowed to osteointegrate with the bone during the healing phase. After osseo-integration, the implant is loaded with a prosthesis to replace the missing tooth. Conventional implant treatment planning uses study models, wax-ups and panoramic x-rays to prefabricate surgical stent to guide the preparation of the implant site. The drilling into the alveolar ridge is invariably a "blind" procedure as the part of the drill in bone is not visible. Stereotactic systems were first introduced into neurosurgery in 1986. Since then, computer-assisted navigational technology has brought major advances to neuro-, midface and orthopaedic surgeries, and more recently, to implant placement. CLINICAL FEATURE: This paper illustrates the use of real-time computer-guided navigational technology in enhancing safety in implant surgical procedures. OUTCOME AND CONCLUSION: Real-time computer-guided navigational technology enhances accuracy and precision of the surgical procedure, minimises complications and facilitates surgery in challenging anatomical locations. (+info)
Analysis of the use of expansion osteotomes for the creation of implant beds. Technical contributions and review of the literature.
Sometimes, the severe superior maxillary atrophy compromises and even impide oral implants treatment. The use of rotatory instruments (drills) produce heat and lost of bone, but the osteotomes in implantology avoid this and simplifies the surgical treatment allowing implant installation with an easier technique. We present an expansive maxillary technique review, describing the main indications, advantages and disadvantages of this surgical procedure. (+info)
Teaching implant dentistry in the predoctoral curriculum: a report from the ADEA Implant Workshop's survey of deans.
In 2004, a survey of the deans of U.S. and Canadian dental schools was conducted to determine the implant dentistry curriculum structure and the extent of incorporating implant dentistry clinical treatment into predoctoral programs. The questionnaire was mailed to the deans of the fifty-six dental schools in advance of the ADEA Implant Workshop conference held in Arizona in November 2004. Out of the fifty-six, thirty-nine responded, yielding a response rate of 70 percent. Thirty-eight schools (97 percent) reported that their students received didactic instruction in dental implants, while one school (3 percent) said that its students did not. Thirty schools (86 percent) reported that their students received clinical experience, while five schools (14 percent) reported that theirs did not. Four schools (10 percent) did not respond to this question. Fifty-one percent of the students actually receive the clinical experience in restoring implants, with the range of 5-100 percent. Of those schools that provide clinical experience in restoring implants, four schools (13 percent) reported that it is a requirement for them, while twenty-eight schools (88 percent) reported that it is not a requirement for them. Three schools (9 percent) did not respond. The fee for implants is 45 percent higher than a crown or a denture, with a range of 0-100 percent. Twenty-nine schools (85 percent) indicated that they did receive free components from implant companies, while five schools (15 percent) did not. The conclusions of this report are as follows: 1) most schools have advanced dental education programs; 2) single-tooth implant restorations are performed at the predoctoral level in most schools; 3) implant-retained overdenture prostheses are performed at the predoctoral level in most schools; 4) there is no predoctoral clinical competency requirement for surgical implant placement in all schools that responded to the survey; 5) there is no predoctoral clinical competency requirement for implant prosthodontics in most schools that responded to the survey; 6) prosthodontic specialty faculty are often responsible for teaching implant prosthodontics at the predoctoral level; 7) periodontics and oral and maxillofacial faculty are commonly responsible for teaching implant surgery at the predoctoral level; 8) support from implant companies is common for dental schools, with most providing for implant components at discounted costs; and 9) there is a lack of adequately trained faculty in implant dentistry, which is a significant challenge in providing predoctoral students with clinical experience with dental implants. (+info)