Advent Of Implants Research Articles

Long-term management of avulsed "hopeless" teeth in the adult dentition.

This case will demonstrate a thoughtful approach to the management of avulsed/replanted teeth in the adult dentition and their long-term maintenance. Often times these teeth are either not replanted, or extracted soon after replantation when resorptive lesions appear and the teeth are deemed "hopeless". The term "hopeless tooth" (HT) has become more popular since the advent of implants. Implants allowed for a simple solution to the HT by extraction and immediate replacement with a fixture and a restoration. However, now that we are realizing that implants do not last forever and also have attendant problems, saving the HT takes on a new light. Prolonging the life of the HT can preserve bone and give the patient a functional, esthetic tooth for many years. With each additional year, clinicians garner new skills, and technology improves our future treatment outcomes. This will allow clinicians to improve and extend the life of future replacements. If there is minimal risk to adjacent structures, retaining the HT has many advantages for the patient and clinician. Clinicians should adopt a policy of thinking ahead and asking "What's Next"? when their prospective treatment fails or needs to be replaced. By prolonging the life of the HT, the "best ultimate treatment" has a greater chance to outlive the patient. With the advent of single tooth implants, the term "hopeless tooth" has become more popular. It is easier to justify extraction of a tooth when it is deemed "hopeless". Many of these teeth could be saved. The advantages of this philosophy will be elucidated.

Study of locator attachment effect in implant-assisted complete lower over denture opposed with dentulous versus edentulous upper arch

Background Rehabilitation of edentulous mandible opposing natural maxillary teeth is associated with many problems. The advent of implants provides a treatment modality that allows the remaining maxillary teeth to be kept. Aim The aim of this study was to evaluate clinically and Radiographically the effect of locator attachment in implant-assisted complete versus single lower overdenture. Materials and methods Twelve patients were selected for this study, half of them were completely edentulous and the other half had edentulous mandible opposing dentulous maxilla. All patients received a lower complete overdenture constructed over two implants, placed at the canine region and retained with locator attachment. Each patient was presented to a questionnaire. The patients were evaluated as regards implant stability, gingival recession, and probing depth. Radiographically, the patients were examined to determine the amount of marginal bone loss. Results The results showed no significant difference in patient satisfaction between the two groups. As regarding the implant stability, gingival recession and probing depth, there was a significant difference of both groups during the follow up period, but the difference was insignificant between both groups at the same follow-up period. Radiographically, there was a significant marginal bone loss during the follow-up period of both groups. In comparing between the two groups, there was an insignificant difference in bone loss between the two groups after 6 months while after 12 months, the difference was signify cant. Locator attachment exhibit high denture stability, better patient satisfaction and accepted clinical parameters and alveolar bone resorption when opposed by dentulous maxilla.

An investigation of complete denture teaching in the UK: part 1. A survey of undergraduate teaching

This paper is the first in a series of two that investigate the undergraduate teaching of complete dentures in the UK. A questionnaire was sent by email to 13 UK dental schools enquiring about the number of hours spent in the lecture theatre, laboratory and clinic. The schools were also asked to give their views about the preparedness of the new graduates for dealing with complete dentures in general practice. There was great disparity between schools in the overall number of lectures delivered. Two schools claimed 28 hours and the remainder varied between 6-15 hours. Four schools devoted more time to laboratory work whereas three schools spent more time in the clinic. One school reported no dedicated clinical time for complete dentures. There appears to be a regional variation with northern UK dental schools spending more time on the teaching of complete dentures. The quota for complete dentures varied from three in most schools to eight in one school and none in another. Comments from the dental schools varied from a reported lack of suitable complete denture cases, to concerns with insufficient curricular time devoted to the subject and a subsequent lack of clinical competence on graduation. Some schools have integrated complete denture teaching into the general prosthodontic course as it is considered inappropriate to teach different aspects of prosthetics in isolation. Competence in complete dentures falls short of what is expected. With a single exception all the schools seem to have low expectations for their undergraduate students to be practically trained and experienced in the production of complete dentures. Despite the advent of implants and the introduction of clinical dental technicians, there is and will continue to be a need for the competent treatment of the edentulous population by general practitioners.

50 years ago in CORR: Biomechanics of hip prostheses. Duncan C. McKeever, MD CORR 1961;19:187-199.

“The fact that a device or a procedure is successful some of the time, most of the time, or even all of the time, does not prove that it is mechanically and physiologically correct.” Thus began Duncan McKeever in his article on, “The Biomechanics of Hip Prostheses,” published in CORR in 1961 [7]. This “axiom” remains true today. Surgeons have recognized the importance of mechanical conditions, and have attempted to explain why implants work and why they fail since the advent of implants and artificial joints in the 1890s [4, 5]. Haboush [6], in explaining the rationale for what was perhaps the first contemporary arthroplasty using cement (1953), designed his implant using mechanical principles. Charnley [2, 3] performed extensive mechanical experiments while developing his arthroplasty. McKeever outlined four mechanical principles in designing a hip prosthesis (presuming it has a stem): (1) the components of stress should have a constant direction; (2) there must be an optimal relation between the maximal stress and the cross-sectional area; (3) the total stress must be transferred at a single level; (4) the range of stress must be within the range of functional adaptation of the bone (Fig. 6). These are undoubtedly sound principles, but the problem was – and is – determining stress histories in an accurate comprehensive, and meaningful way. Today, stresses throughout a complex structure, such as a bone-implant construct, can be estimated using increasingly sophisticated finite element analyses, but these analyses do not account for the dynamic nature of the stresses nor the manner in which bone adapts to the constantly changing stresses during function [1]. Further, the precise nature of the stress transfer varies from patient to patient, and more generic estimates of that transfer may not apply. Fig. 6 McKeever’s illustration shows the four principles he outlined in his text and the additional point about where the “total stress” is transferred to bone. In fact, stress transfer will occur throughout the interface, depending upon ... McKeever did not have the ability to estimate the stresses at his disposal, but he commented, “The stem of the prosthesis should act only as a directional device only, and none of the stress should be transmitted through it.” He presumed all of the stress would be transferred at the point of maximal contact (Fig. 6). We now know this is not the case. Because of the uncertainties of stress transfer and bone response, empiricism has always played a role in the development of arthroplasties. Implants may be designed on a sound theoretical basis, but may not account for all in vivo conditions or unanticipated responses or reactions; thus, it is hard to predict whether a given arthroplasty will be durable, and much of the advances have occurred through trial and error. McKeever concluded, “Our salvation in many of the more serious problems of bone surgery lies within the field of mechanics and structural design as related to physiology. To think along these lines will avoid some of the complications and some of the failures.” In a strict sense, he was correct, but 50 years later, we still do not adequately understand the details of bone adaptation in general or in specific individuals to design an implant that will be durable in all patients.

Treatment Planning: A New Paradigm

The introduction and success of dental implants has had positive results for many patients but has also caused turmoil in the treatment planning arena. The advent of implants as a predictable clinical treatment modality has modified the traditional endodontic treatment planning paradigm. Previously, patients having a tooth at risk were evaluated by a generalist or sent to an endodontist to determine the prognosis of an endodontic procedure. Today, that pathway has been markedly altered. Patients are commonly sent to periodontists or oral surgeons to determine the best treatment plan for the patient. It is not surprising that those specialists’ skill set and experience often leads them to conclude that an implant is the best plan. The endodontist is often shut out of the treatment planning process. Many endodontists in the U.S. believe that teeth that could be saved by basic endodontic procedures are no longer even considered for treatment. In an environment colored by overstatements and half-truths, facts can be difficult to find. Efforts have been made to compare the prognosis of an implant to that of an endodontically treated tooth. Anecdotal evidence is often seized upon to prove a debating point. However, studies with small sample sizes, varied recall periods and different outcomes measures cannot be compared. A comparison between the prognosis of an endodontically treated tooth and an implant is dependent on many variables. Comparisons between the clinical modalities are complicated by confounding variables. It has been said that in clinical research there are variables that we can recognize and control, other variables that we can recognize but can not control and still others that we neither recognize nor control. The best available evidence indicates that when appropriately completed, both endodontics and implants have a remarkably high level of success. However, there are factors that modify the prognosis in both situations. The systemic health of the patient, smoking, periodontal problems as well as tooth anatomy and occlusion may all affect the outcome of the case. What does seem clear is that the patient is best served by retaining their natural dentition as long as the prognosis for long-term retention is positive. It makes no sense to extract a treatable tooth if a highly predictable endodontic procedure can be performed. On the other hand, it makes no sense for a patient to invest in root canal therapy, a post and crown if the prognosis is highly questionable and an implant with a good prognosis can be placed. Unfortunately, the endodontist is often marginalized in today’s treatment planning process. This is to the detriment of the patient. A central question concerning this matter is, “How are our patients best served?” A patient would benefit from the participation of an endodontist in the development of their treatment plan. In the current environment this will require an endodontist with additional knowledge. An endodontist with “dual training” that is endodontic and implant training would represent a formidable practitioner. The patient would benefit by seeing a clinician with skills in both areas, thus avoiding a bias in treatment planning. All that separates the endodontist from that role is the necessary education in implantology. In the U.S., some post-graduate programs have already taken steps in that direction. At least one program is building a faculty with dual training and some of the faculty are already including implant placement in their practices. Other post-graduate curriculums are including aspects of implant dentistry and are encouraging their students to go further with this phase of their education. Consider the value to the patient of seeing a clinician who can examine them from the perspectives of endodontics and implants and determine their best course of treatment without a bias. Specialties have always redefined themselves. Evidence of change abounds. Simply consider the periodontist of today with their emphasis on implants as compared to the periodontist of twenty years ago and their focus on tooth retention. The question is not who should be doing implants. The appropriate question is how we can best serve our patients. It is time for endodontists to redefine our specialty in order to provide our patients with the highest level of care.