Single-tooth Implants Research Articles

Biologic and mechanical stability of single-tooth implants: 4- to 7-year follow-up.

Single-tooth implants have been reported to achieve a high level of surgical and prosthetic success. However, close inspection of the literature reveals a paucity of data on the follow-up of single-tooth implants in function for 5 years or more. Since unsplinted implants may be considered to be subject to greater functional stresses, there is a need to report on the long-term biologic and mechanical integrity of such implant-supported restorations. To report on the long-term follow-up of single-tooth implants, restored and in function for 4 to 7 years. Twenty-seven Astra Tech single-tooth implants were subject to a clinical audit to evaluate implant and prosthetic success as well as response of both hard and soft tissues over a 1- to 4-year follow-up. This current report presents data on the biologic and mechanical integrity of 23 of these single-tooth implants, which have been in function for up to 7 years (mean, 63 mo). Data are provided with respect to implant survival, maintenance of marginal bone levels, soft-tissue health, and the recording of any adverse events, including prosthetic complications. Only 14 implants in 13 patients were available for review, with no failures for this group of implants. One patient from the original group, who was lost to follow-up, was known to have suffered an implant failure. Furthermore, in accordance with established criteria, the remaining 13 implants that are not included in this report must at this time also be considered as potential failures. As such, the best-case scenario would be a 95.6% success rate for the 23 implants included in this review and the worst-case scenario would be a 60.8% success rate. Mean marginal bone loss measured 0.49 mm mesially and 0.76 mm distally, with a frequency of bone loss of 50%. Soft tissues were clinically healthy. There were few adverse events, with only one case of abutment screw loosening, detected at the 6-year review. In addition, crown decementation was recorded three times in two patients. It can be concluded that the Astra Tech single-tooth implant can achieve long-term biologic and mechanical stability when used to restore single missing teeth, over the long-term.

Impact of conventional tomography on prediction of the appropriate implant size.

The purpose of this study was to evaluate the efficacy of conventional cross-sectional tomography in predicting the appropriate implant size. The implant length and width of 46 patients referred for single tooth implant treatment were determined presurgically by periapical + panoramic images (record 1) and after surgery by periapical + panoramic images + tomograms (record 2). These dimensions were compared with the dimensions of the implants actually installed (record 3), as well as the dimensions assessed to be the "appropriate" ones according to defined criteria for success (record 4). In 70% of the cases, the implant length or width, or both, was changed after the tomogram was available. The implant dimensions determined with tomography were maintained at surgery in 87% of the cases. In only 33% of the cases did the implant size predicted without tomography correspond with the size of the installed implants. The agreement between records 2 and 3 was significantly higher than between records 1 and 3 (P < .001). Similarly, the agreement between records 2 and 4 was significantly higher than between records 1 and 4 (P < .001). This study demonstrated that the use of tomograms increases the efficacy of periapical + panoramic images, with respect to the prediction of appropriate implant size, by a factor of 2.5. Therefore, conventional cross-sectional tomography is recommended for treatment planning before installation of single tooth implants.

Single tooth implants have acceptable 4-year survival rates

Objective: To systematically review clinical studies on the performance of implant-supported single-tooth restorations (STR). Data sources: Medline 1990–1998, using keywords, ‘dental in SB’, ‘implant’ and ‘single’. Study selection: Only English papers that met a strict three-level selection procedure, including availability of or the ability to calculate life-table survival curves, were included. Data extraction and synthesis Cumulative life-table survival curves were constructed by pooling data from the included studies to new data sets. Results: Of 332 papers initially identified, the majority were excluded because they were case reports, technical notes or descriptions of clinical procedures. Nine studies met all the criteria with the data predicting a 97%(±1%) survival implant survival at 4 years, with an uncomplicated crown survival rate of 83%(±3%). Conclusions: Single tooth implants have an acceptable short-term survival rate. More information and better quality clinical studies and reporting are needed, however. Creugers NHJ, Kreulen CM, Snoek PA, deKanter RJAM. A systematic review of single-tooth restorations supported by implants. J. Dent 2000; 28:209–217

Two-stage implant systems.

Since the advent of osseointegration approximately 20 years ago, there has been a great deal of scientific data developed on two-stage integrated implant systems. Although these implants were originally designed primarily for fixed prostheses in the mandibular arch, they have been used in partially dentate patients, in patients needing overdentures, and in single-tooth restorations. In addition, this implant system has been placed in extraction sites, in bone-grafted areas, and in maxillary sinus elevations. Often, the documentation of these procedures has lagged. In addition, most of the reports use survival criteria to describe results, often providing overly optimistic data. It can be said that the literature describes a true adhesion of the epithelium to the implant similar to adhesion to teeth, that two-stage implants appear to have direct contact somewhere between 50% and 70% of the implant surface, that the microbial flora of the two-stage implant system closely resembles that of the natural tooth, and that the microbiology of periodontitis appears to be closely related to peri-implantitis. In evaluations of the data from implant placement in all of the above-noted situations by means of meta-analysis, it appears that there is a strong case that two-stage dental implants are successful, usually showing a confidence interval of over 90%. It also appears that the mandibular implants are more successful than maxillary implants. Studies also show that overdenture therapy is valid, and that single-tooth implants and implants placed in partially dentate mouths have a success rate that is quite good, although not quite as high as in the fully edentulous dentition. It would also appear that the potential causes of failure in the two-stage dental implant systems are peri-implantitis, placement of implants in poor-quality bone, and improper loading of implants. There are now data addressing modifications of the implant surface to alter the percentage of osseointegration. New types of reinforcements for dental implants and the use of growth factors to augment bone regeneration so that implants can be placed more easily are now being actively investigated.

Marginal bone levels at single tooth implants with a conical fixture design. The influence of surface macro- and microstructure.

The concept of a conical implant design to accommodate single tooth replacement, has previously been shown to result in excessive bone loss, around the machined titanium conical collar, usually down to the 1st thread. This unusually aggressive loss of bone was shown to occur within a short period of time, post loading, with greater than 3 mm of bone loss occurring within the 1st 6 months to 1 year. The influence of implant design, surface texture and microleakage have all been highlighted as a potential cause. A modification of the surface structure, both at the macroscopic and microscopic level, as well as an altered fixture-abutment interface design has resulted in the maintenance of marginal bone around a single tooth titanium implant with a similar conical design. The radiographic follow-up of 33 implants loaded for up to 4 years, has revealed, by comparison, a most favourable maintenance of marginal bone around the conical collar, with a mean marginal bone loss of 0.32 mm mesially and 0.34 mm distally for the whole group. The cumulative mean marginal bone loss mesially and distally is 0.42 mm and 0.40 mm from 1 to 2 years, 0.54 mm and 0.43 mm from 2 to 3 years, 0.51 mm and 0.24 mm from 3 to 4 years, and 0.62 mm and 0.60 mm for implants past their 4 year recall.

A minimally invasive second-stage procedure for single-tooth implants

The natural look of dental restorations has become a universally claimed treatment objective, especially when single-tooth gaps are restored with implants. A harmonious gingival margin is crucial to achieve this goal. This article presents a new procedure for exposure of single-tooth implants that yields a favorable esthetic result in the visible maxillary regions because of the simple type of incision used. The procedure consists of two incisions: the first incision makes it possible to find out the implant position and the second incision shapes the mucous membrane according to local supply. The second incision also prevents the soft tissue from tearing after careful stretching and subsequent pressing of the supraimplant mucosa. There is minimal soft tissue traumatization, and as a result, healing time can be reduced to 1 week and an appealing esthetic result can be reached. (J Prosthet Dent 1998;79:217-19.)

Issues Related to Single-Tooth Implants

Many practitioners place single-tooth implants when the teeth adjacent to the edentulous space are intact, free of caries and have had no restorations, and the patient is reluctant to wear a removable appliance for physical or psychological reasons, or both. The main exclusionary factors for a single-tooth dental implant are insufficient bone quantity, poor bone quality and insufficient vertical interarch space to accommodate the prosthodontic components of the implant.

Single-tooth implants: A procedure to make a precise, flexible gingival contour on the master cast

Single-tooth implants: A procedure to make a precise, flexible gingival contour on the master cast

Use of an Osseointegrated Implant for Dental Rehabilitation after Cleft Repair by Periosteoplasty: A Case Report

We report here on a patient with unilateral cleft lip and alveolus who underwent dental rehabilitation of cleft alveolus using an osseointegrated implant after cleft repair by periosteoplasty. The patient, whose lateral incisor was congenitally missing, had periosteoplasty, followed by excellent bone formation at the cleft alveolus within 2 years. After the completion of orthodontic alignment of the maxillary dental arch, a Brånemark single-tooth implant was placed into the bone-formed alveolus. This treatment procedure offers an option of dental rehabilitation for the alveolar clefts of patients with cleft lip and/or palate.

OR 55 Single-tooth implants in endodontics: results and experiences of a retrospective study after 4 years

OO__R I ,Single-tooth implants in enclodonUcs: results and experiences of a retrospective study after 4 years R HERNANDEZ DMD*, TJ BALSHI DDS FACP The aim of this study is to present results and experiences of a retrospective analysis of single-tooth replacement for endodontically failed teeth using osseointegrated implants in immediate extraction sites. 94 Brn vertical root fractures, 17 (22%); trauma, 13 (16.8); horizontal root fracture, 4 (5.1); cervical root resorption, 4 (5.1%); furcation or root perforation, 4 (5.1%); combined endodontic/periodontic lesions, 3 (3.8%); presence of pain after endodontic therapy, 3 (3.8%); fistula not resolved, 1 (1.2%); other, 5 (6.45%). All patients were followed for 4 years focusing on implant success and crown function. Plaque and gingival indexes, and probing depths were recorded around teeth and implants. Only 5 implants (5.3%) were lost by the first annual check-up; none after. A total of 89 implants were clinically and radiographically evaluated at the 4 year recall, resulting in a cumulative success rate of 99.5% in the maxilla (59 implants) and 97% (30 implants) in the mandible. Plaque and gingival indexes showed good health around both natural teeth and tissue integrated prostheses. The outcome of this study indicated that safe and highly predictable results can be obtained when osseo nte.qrated implants are used to immediately replace endodontically failed teeth.

A comparative prospective clinical study of two single-tooth implants: A preliminary report of 102 implants

Statement of problem. Treatment of tooth loss in the anterior maxilla can involve difficult functional, esthetic, and psychologic problems, especially in young patients with otherwise good dentition. Purpose. The purpose of this study was to provide a preliminary comparative evaluation of two implants (ITI and Astra) in single-tooth restorations. Material and methods. This prospective study of 102 single-tooth replacements with 56 ITI and 46 Astra dental implants was performed in 82 patients at the Finnish Student Health Service Foundation. One Astra implant was lost before loading. The overall survival rate of the implants was 97.8% for Astra implants and 100% for the ITI system. After the initial healing period of at least 6 months, the remaining 101 implants (56 ITI, 45 Astra) were free of periimplant infection and revealed no detectable mobility. Radiographs did not reveal signs of periimplant radiolucencies. All 101 implants received single-tooth crowns. Results. Periimplant parameters and acceptable implant function were examined and demonstrated satisfactory results with preestablished clinical parameters and radiographs at 1 year. During the observation time the mean marginal bone loss was 0.13 mm with Astra implants and 0.11 mm with ITI implants. Subjectively all patients were satisfied with their single-tooth restorations supported by either ITI or Astra dental implants. Conclusion. The favorable results of this short-term study support the application of the two implant systems for single-tooth restorations, especially in the anterior region of the maxilla. (J Prosthet Dent 1997;77:382-7.)

Interdisciplinary management of single-tooth implants

Orthodontists treat many patients who are missing maxillary lateral incisors and/or mandibular second premolars. In the past, if the canines could not be substituted for lateral incisors, conventional full-coverage bridges were the common restoration. Recently, resin-bonded Maryland bridges became a popular substitute for conventional bridges to avoid crowns on the nonrestored abutments. However, resin-bonded bridges have a poor long-term prognosis for retention, lasting on average about 10 years. Since implants were introduced into dentistry by Swedish researchers in the mid-1980s, they have become a promising substitute for conventional or resin-bonded bridges. However, to successfully place and restore single-tooth implants in young orthodontic patients several questions must be answered. This article will discuss the many interdisciplinary issues that are involved in placing and restoring single-tooth implants in orthodontic patients.

The abutment seating jig: a prosthodontic implant adjunct.

Rapid, accurate seating of screw-retained implant abutment heads, where timing is controlled by internal or external hex designs, can be readily accomplished with individual, custom-cast abutment head location devices. The devices are especially useful when the abutment head-implant body complex is to be permanently cemented. The use and design of abutment seating jigs for single tooth implants and completely implant or implant and natural tooth-supported prostheses are described.

Clinical and radiographic findings following placement of single-tooth implants in young patients—case reports

Clinical and radiographic findings following placement of single-tooth implants in young patients—case reports

Three-dimensional finite element analysis of stress-distribution around single tooth implants as a function of bony support, prosthesis type, and loading during function

The elastic limit of bone surrounding implants may be surpassed and thus produce microfractures in bone. The purpose of this study was to use computer simulations to examine clinical situations with IMZ implants in edentulous mandibles and to identify loading conditions that could lead to bone microfractures. Three-dimensional finite element analysis models were used to examine effects of: (1) types of edentulous mandibles, (2) veneering materials, (3) the absence of cortical bone, (4) different intramobile elements, (5) loading directions, and (6) loading levels. Stress distribution patterns were compared and interfacial stresses were monitored specifically at four heights along the bone-implant interface. Stresses were concentrated toward cortical bone (0.8 to 15.0 MPa). There were no differences between types of veneering materials and the absence of cortical bone increased interfacial stresses. The use of a titanium intramobile element decreased stresses. Minor stress increases were associated with smaller mandibles. Oblique loads increased stresses 15 times, and 200 N loads increased stresses 10 times. Conditions for bone microfracturing were associated with oblique loads, high occlusal stress magnitudes, and the absence of cortical bone.

Immediate and Single Tooth Implants with Frialit

Immediate and Single Tooth Implants with Frialit

Immediate and Single Tooth Implants with Frialit

Immediate and Single Tooth Implants with Frialit

A study of 184 consecutive patients referred for single-tooth replacement.

The aim of this investigation was to study the acceptance and the rejection of patients referred for single implant restorations based on data from referral, case history, clinical examination and therapy planning. The referrals comprised 184 patients with 251 missing single teeth. Sixty-four per cent of the referred patients were accepted for treatment. There was a difference in acceptance between men and women (75% and 54%, respectively). A negative relationship was noticed between age and acceptance. External trauma (33%), root fractures (16%) and congenitally missing teeth (15%) were the main reasons for lost or missing teeth. Anatomical limitations was the most frequent reason for rejection (76%). Most fillings and crowns on adjacent teeth to the edentulous space did not serve as a contraindication for an implant single-tooth restoration, and thus extensive fillings or not acceptable crowns was the cause of rejection only for a minor group (13%). The great majority of the partially dentate patients showed a very high interest in treatment with single-tooth implants, but some of the patients (4% in all, 11% of those rejected for treatment) did not want implant treatment after having received further information at the specialist clinic.

Restoring gingival harmony around single tooth implants

One of the biggest challenges to restoring a single tooth implant in the esthetic zone of the mouth is the creation of harmonious gingival contour around the restoration. Soft- or hard-tissue deficiencies of the edentulous space are the most common obstacles to achieving gingival symmetry around the proposed restoration. Numerous gingival and osseous grafting and regeneration techniques are available but may complicate treatment by increasing the number of surgical procedures and sites necessary. This article describes a technique for treating mild-to-moderate ridge defects without the required additional surgical procedures or a surgical donor site. Soft-tissue overcontouring is provided around the healing abutment by modification of the surgical flap at second-stage implant surgery. Subsequent gingivoplasty allows establishment of anatomic gingival architecture that surrounds the single implant prosthesis.

Osseointegrated implants for single tooth replacement in general practice: A 1‐year report from a multicentre prospective study

The single tooth implant is a treatment option for the replacement of missing single teeth and in many cases is the treatment of choice. It is, however, an expensive treatment requiring a co-ordinated approach to the surgical and restorative aspects of treatment. In this study, a group of dentists in general and restorative dental practice and with no previous experience in implant surgery underwent an intensive training course in all aspects of implant treatment for single teeth. Using a system of simplified instrumentation with a strict adherence to protocol, the group installed and restored single tooth implants ad modum Brånemark in a wide range of clinical situations. At the one year follow-up period following crown insertion, the success rate of treatment compared favourably with results reported from centres using the specialist team approach to treatment. The results of this study indicate that further consideration should be given to the training of general dentists so that improved delivery of dental health care can be provided at a more economic level.