Patient's opinion and treatment outcome of fixed rehabilitation on Brinemark implants. A 3‐year follow‐up study in private dental practices.

In this study, patient opinion on oral rehabilitation by means of Brånemark implants was investigated. All patients were referred to a periodontal clinic for implant installation and treated by one and the same operator. Prosthetic restorations were performed by dentists, who had no previous experience with prostheses on implants, but had completed a postgraduate training course. Patient opinion was obtained through questionnaires, pertaining to satisfaction and oral function. A comparison was made between pre‐implant situation, short‐term (<4 months) and long‐term functioning )3 years( with the implant‐restorative rehabilitation. In total, 61 patients participated in the study; 23 received a full lower arch bridge and 18 a full upper arch bridge, while 20 patients got partial bridges. Of 298 installed implants, 7 failed at abutment connection (2.3%) and 1 during the 3‐year follow‐up interval (0.3%). The study results indicated that a great majority of patients were very satisfied with the treatment. Comfort with eating, aesthetics, phonetics and overall satisfaction improved significantly and nearly all patients said that they would undergo the treatment again or recommend it to others. Patients experienced their implants as "natural" teeth. The conclusion is that rehabilitation ad modum Brånemark, even in the hands of non‐specialized dentists, can be of high quality, improving oral function and satisfying the needs and demands of patients.     

Periodontal parameters of osseointegrated dental implaits. A 4‐year controlled follow‐up study

The aim of this study was to evaluate the periodontal parameters of osseointegrated dental implants. The condition of the peri‐implant mucosa was assessed using periodontal parameters, i.e., of plaque index, bleeding on probing, probing pocket depth, probing attachment level and Periotest® scores as well as a radiographic parameter, over a 4‐year follow‐up period. 32 non‐submerged ITI dental implants, all placed in the mandible, were studied in 12 patients who had good oral hygiene. All patients were regularly recalled at 6‐month intervals. The overall implant success rate was 100%. None of the implants showed any signs of inflammation, radiographic bone loss or any detectable mobility during the follow‐up period. Methods similar to those used to evaluate the natural dentition were effectively employed to assess the clinical status of the dental implants. The diagnostic value of these parameters could not, however, be determined from this study due to the absence of any peri‐implant tissue complications. The results indicated that some periodontal parameters of healthy peri‐imolant mucosa might be slightly different from healthy periodontal tissue.     

Peri‐implant mucosal aspects of ITI implants supporting overdentures. A five‐year longitudinal study.

Sixty‐six ITI implants placed in the mandible of 33 edentulous elderly patients (mean age: 69 years) were observed longitudinally for 5 years. The implants served as overdenture anchorage either by means of a connecting bar or single spherical attachments. During the study period, 2 implants failed (one because of a peri‐implant lesion and one because of a fracture) and had to be removed. At the beginning of the study, all implants were osseointegrated and had successfully been in function for 335 months. Oral hygiene practices and the peri‐implant mucosal status were assessed according to the criteria of conventional periodontal parameters. Approximately 50% of the implants had been installed into lining mucosa and hence were to surrounded by keratinized mucosa. The peri‐implant mucosal tissue was maintained healthy during the whole observation period, and no or only minimal loss of attachment was observed. The probing depths averaged approximately 3 mm. At the end of the study, orthopantomographic radiographs were obtained from all patients to assess the peri‐implant bony structures. Small local angular bony defects were detected on 16 implants (22%) in 12 patients. Slightly increased probing depths were observed when angular bony defects were present. Loss of attachment was significantly less frequent when the implants had been placed following a prolonged period of edentulousness (<5 years). This study demonstrated that advanced age, reduced dexterity of elderly patients and environmental conditions of overdentures do not represent a 1 higher risk for the development of peri‐implant lesions.     

A prospective 15‐year follow‐up study of mandibular fixed prostheses supported by osseointegrated implants. Clinical results and marginal bone loss.

In this prospective study 47 edentulous patients were treated with mandibular fixed prostheses supported by osseointegrated Brånemark implants and followed for 12 to 15 years. Three 1%) of the 273 inserted implants were lost, two before and one six years after placement of the fixed prosthesis. The cumulative success rate CSR) of the implants was 98.9% both after 10 and 15 years. None of the fixed prostheses was lost and at the last follow‐up, all patients had stable fixed prostheses in function (CSR 100%). The marginal bone loss around the implants was small, on average 0.5mm during the first post surgical year and thereafter about 0.05mm annually. More bone was lost around the anterior implants than around the most posterior ones. Smoking and poor oral hygiene had significant influence on bone loss, while occlusal loading factors such as maximal bite force, tooth clenching and length of cantilevers were of minor importance. It is concluded that the long‐term results of the mandibular implant treatment were extremely successful, regarding both the fixed prostheses and implant stability. Bone resorption around the implants, albeit limited, was influenced by several factors, smoking and oral hygiene appeared to be most important.     

Patient evaluation of treatment with fixed implant- supported partial dentures

The aim of this study was to analyse the patient evaluation of functional treatment outcome in 40 periodontally compromised patients who received implant-supported prostheses (ISPs) as part of the total treatment. The treatment protocol comprised periodontal treatment, extraction of teeth with poor prognosis, placement of dental titanium implants, and after healing, insertion of fixed ISPs. Five of the patients became edentulous in one jaw after extraction of all teeth and received a complete ISP, whereas 35 patients became partially edentulous after extraction of some teeth, 12 receiving a partial ISP on > or = 3 implants, and 23 one on two implants. The follow-up period was on average 1.8 years after the connection of the prostheses, which provided the patients a dentition with a mean of 12 occluding dental units. The first author (S.-W. Yi) performed all implant treatment. Patients' opinions on oral functions--mastication, phonetics, oral hygiene, chewing comfort and aesthetics--were evaluated by means of a questionnaire both before implant installation and at the last follow-up. A control group of 30 subjects with a healthy dentition of 14 occluding natural pairs of teeth answered the same questionnaire on one occasion. A great majority of the patients were extremely satisfied with the oral function after treatment and experienced the ISPs as 'natural teeth'. There was no significant difference between the three treatment groups and the control group for mastication, phonetics, chewing comfort and aesthetics. Patients with ISPs reported a small but significantly greater difficulty with oral hygiene procedures than the controls with natural teeth. Most patients said that they would undergo the treatment again, if necessary, and recommend it to others. It was concluded that the rehabilitation of the periodontally compromised patients, including ISPs on osseointegrated dental titanium implants, resulted in subjectively improved and satisfactory oral function.     

Non‐submerged implants in the treatment of the edentulous lower jaw. A 2‐year longitudinal study.

Non‐submerged ITI Bonefit implants ITI Dental Implant System) were inserted in edentulous lower jaws of 46 patients. The patients were provided with either a fixed prosthesis or an overdenture, and has been followed during a 2‐year‐period. At the 1‐year examination, the suprastructures were removed permitting test of the individual implant stability. Radiographic examinations were performed in connection with the loading of the implants and at the 1‐year examination. In total 216 implants were inserted. 4 implants were lost before loading and 4 during the 2nd year of function, which gives a survival rate after 1 year of 98% and after 2 years of 96%. The mean marginal bone loss during the first year of function was 0.1mm. However, the marginal bone changes had a high degree of variation and four implants showed a severe bone loss. The intention is to follow this patient group with annual examinations during 5 years.     

Accuracy of radiographic diagnosis of peri‐implant radiolucencies -‐ an in vitro experiment

The absence of a peri‐implant radiolucency on radiographs is used as a criterion for implant success. The purpose of the present study was to evaluate the accuracy of diagnosing peri-implant radiolucencies using an experimental model. Astra Tech fixtures were inserted into 20 bony specimens. Later, the fixtures were removed and the prepared cavities were enlarged in 2 steps. The specimens were radiographed under strictly standardized circumstances in the 3 stages ("press‐fit"= simulated osseointegration, and "0.1 mm space" and "0.175 mm space"= simulated connective tissue layer". All specimens were radiographed with 2 vertical angulations (0" and 15"). Ten observers read the radiographs and evaluated bone‐implant relationship on a 5‐point scale. The interobserver agreement was low. Specificity was remarkably low, and sensitivity was moderate. A significant difference in diagnostic accuracy was found for 0.175 mm peri‐implant space compared to 0.1 mm space. The diagnostic accuracy was found to be highest for 0.175 mm peri‐implant space specimens. It is concluded, that radiography seems to be an unreliable method for diagnosing peri‐implant spaces, although accuracy improved at increasing space widths. Strict orthogonal projection angles did not improve diagnostic accuracy.     

Patient satisfaction and quality of single-tooth restorations

Abstract: This retrospective study focuses on patient opinion and professionally assessed quality of single‐tooth restorations of Brånemark fixtures. Patients were treated by periodontists for fixture installation and/or abutment connection and by referring general practitioners for prosthetic rehabilitation. Seventy‐eight consecutively treated patients were sent a questionnaire regarding aesthetics, phonetics and overall satisfaction. Forty‐eight patients (52 fixtures) returned the questionnaire. Forty were able to attend a clinical examination by an independent examiner. The quality of 43 single implant crowns was evaluated according to the modified guidelines for assessment of quality and professional performance used for evaluation of design, fit, occlusion/articulation and aesthetics. Bone to implant level was assessed radiographically. Patients were very positive about aesthetics, phonetics, eating comfort and overall satisfaction. Nevertheless, 6/40 patients would not undergo the same treatment again, yet all of them would recommend it to others. The professionally rated quality of the crowns was perfect in 17 and acceptable in 25 cases. One crown needed modification to prevent future complications. Two crowns had already been replaced as a result of porcelain fracture; one restoration showed abrasion and one was damaged. With a mean loading time of 33 months (range: 3–89 months), none of the patients returning the questionnaire had encountered fixture loss. All except five fixtures showed bone remodelling at or above the first implant thread. It is concluded that single Brånemark fixtures installed by periodontists and restored by general practitioners are of an acceptable clinical quality to satisfy the patient.     

A new design for a hybrid prosthesis supported by osseointegrated implants: 2. Preliminary clinical aspects.

A fixed partial denture is preferred as a prosthetic restoration supported by tissue-integrated oral implants. However, there are occasions, especially in restoring an edentulous maxilla, when a fixed partial denture does not satisfy a patient's requirements for esthetics, good phonetics, proper oral hygiene, and oral comfort. A removable hybrid prosthesis attached to a bar that is conventionally fixed to tissue-integrated implants ad modum Br?nemark was therefore designed to satisfy such needs and to meet requirements for splinting of the implants. Following the placement of prostheses, patients were asked to give their opinion on the comfort, phonetics, and esthetics of the prosthesis by marking a visual analog scale. The results indicate a successful initial outcome of the treatment.     

Non‐submerged osseointegrated dental implants with ball attachments supporting overdentures in patients with mandibular alveolar ridge atrophy. A short‐term follow up.

Non‐submerged, hollow screw ITI‐Bonefit dental implants with ball attachments supporting overdentures were used as alternative treatment to combined vestibulo‐lingual‐plasty with free split‐thickness skin graft and removable dentures in 40 consecutive patients with mandibular alveolar ridge atrophy. One hundred and fifty‐six non‐submerged fixtures were installed. Ball attachments were mounted on the fixtures and implant‐supported overdentures inserted 34 months after fixture installation. The observation period after implant activation and prosthesis insertion varied from 1 to 3 years with a median observation period of 2 years. The overall success rate of individual implants was 99%(155/156). The prosthesis function rate was 100%(40/40). The 1‐year success rate of individual implants was 99%(155/156) with a prosthesis function rate of 100% 40/40. No persistent surgical, periodontic or prosthodontic complications were observed. The results indicate that non‐submerged osseointegrated ITI‐Bonefit dental implants with ball attachments supporting overdentures can be a successful alternative to combined vestibulo‐lingualplasty with free split‐thickness skin graft and removable dentures, and as successful as the use of submerged dental implants.     

Microbial colonization on natural tooth structure compared with smooth and plasma‐sprayed dental implant surfaces

The purpose of this study was to characterize and compare by scanning electron microscopy (SEM) the maturation of supragingival microbial plaque on enamel and smooth titanium and that of subgingival plaque on cementum, plasma-sprayed titanium and hydroxyapatite surfaces. Specimens (6.5 x 2 x 1 mm) were obtained from titanium implants with smooth transmucosal collars and plasma‐sprayed endosseous posts of titanium or hydroxyapatite. Unerupted third molars were sectioned to similar dimensions that included equal lengths of enamel and root surface. Ten patients with post‐treatment pocket depths of > 6 mm on 3 non‐adjacent teeth were selected and each had 1 set of the 3 specimen types bonded by random assignment to the selected teeth. Specimens were positioned so that enamel and/or smooth titanium surfaces were supra‐gingival and cementum and titanium or hydroxyapatite plasma‐sprayed surfaces were subgingival. Patients were instructed to stop oral hygiene, after which 2 specimen sets were removed at 1, 3, 5, 7 and 10 days. Two specimens of each type were examined by SEM at each time interval for supra‐ and subgingival plaque. The sequence of appearance of various microbial morphotypes in supra‐ and subgingival plaque was similar regardless of surface. In both supra‐ and subgingival plaque, depending on time interval, cocci, rods of various lengths, filamentous organisms, fusiforms, spirochetes and corn‐cob formations were observed. Mineralized plaque was noted on most subgingival specimens by day 10. These observations indicate that surface of natural teeth, smooth titanium and plasma‐sprayed titanium and hydroxyapatite support the maturation of microbial plaque with the successive inclusion of a variety of morphotypes.     

Marginal tissue response adjacent to Astra Dental Implants® supporting overdentures in the mandible. A 2‐year follow‐up study.

The aim of this study was to evaluate the marginal tissue response adjacent to implant supported overdentures. Twenty edentulous patients had 2 Astra Dental Implants® placed in the canine region of the lower jaw. New overdentures were retained by individual ball attachments in 11 patients and by a bar attachment in 9 patients. Periodontal registrations were recorded 0 months, 6 months, 12 months and 24 months after the overdentures were inserted. One of the 40 fixtures was lost at the stage of abutment connection. No fixtures were lost during the 2‐ to 4‐year observation period and no fixtures showed any periodontal signs of failure. At the 2‐year examination, no pocket depths adjacent to the implants exceeded 4 mm and no bone loss exceeded 3 mm. The mean annual bone loss was less than 0.2 mm during the first 2 years. The preliminary results from this limited study were promising and showed that two osseointegrated Astra Dental Implants® could successfully retain an overdenture in the lower jaw. However, long‐term observation is needed for a definate evaluation of this treatment concept.     

Mandibular overdentures supported by two Brånemark, IMZ or ITI implants. A prospective comparative preliminary study: One‐year results.

The aim of this prospective comparative study was to evaluate the condition of the peri‐implant tissues of three different implant systems supporting a mandibular overdenture. Ninety edentulous patients (Cawood class V–VI) participated in this study. After randomization, 30 patients were treated with 2 Brånemark implants, 30 patients with 2 IMZ implants and 30 patients with 2 ITI implants. The implants were inserted in the canine region of the mandible. After 3 months overdentures were fabricated supported by a round bar and clip attachment. A standardized clinical and radiographic evaluation was performed 0,6 and 12 months after insertion of the denture. The intra‐oral radiographs were made, using the long‐cone technique with an aiming device. Two implants were lost (1 Brånemark, 1 IMZ) during the healing period. None of the patients showed any sensory change in lip or chin region. The pocket depth in the Brinemark group decreased significantly whereas the mucosa recession increased significantly in both the Brånemark as well as in the IMZ group. After 12 months, there was significantly less bone loss in the ITI group. From our study it was concluded that 2 (Brånemark, IMZ or ITI) implants placed in the interforaminal region connected with a bar supply a proper base for the support of a mandibular overdenture in the (Cawood V–VI) edentulous patient. The ITI implant appears to be the implant of choice for mandibular overdenture therapy. because only one operation is required for a comparable result.     

Overdentures sumorted bv two IMZ implants in the lower jaw. A retrospective study of peri‐implant tissues.

Between 1987 and 1990, 57 edentulous patients were treated with overdentures supported by 2 endosseous IMZ implants connected by a bar in the lower jaw. The condition of the peri‐implant tissue was evaluated for a loading period ranging from 12 to 57 months (mean 30 months and median 24 months). The evaluation parameters included Plaque Index, Bleeding Index, Gingiva Index, pocket depth, dysesthesia of chin or lip, peri‐implant bone loss and loss of implants. During the healing phase prior to the construction of an overdenture, 3 implants were lost. After a healing period of 6 months, these implants were successfully replaced. During the follow‐up period, a Plaque Index ≤1 was observed in 45 patients and an abundance of plaque and calculus was observed in 1 patient. Heavy or profuse bleeding and severe gingival inflammation was observed in 3 patients. The mean pocket depth was 3.6±1.7 mm. None of the patients experienced lip or chin dysesthesia. Marginal bone loss was observed around 30 (26%) implants. From this study it is concluded that, once proper osseointegration is obtained, 2 IMZ implants connected with a bar in the lower jaw supply a proper base for the support of an overdenture; the condition of the peri‐implant tissues is steady and independent of the follow‐up time.     

Initial healing in the dog of submerged versus non‐submerged porous‐coated endosseous dental implants

It has previously been reported that porous‐coated root form endosseous dental implants, became well integrated when used in the traditional 2‐stage surgical approach. In this study, the placement of the implant in a 1‐stage (non‐submerged)technique was to be explored. Implants were placed in the mandibles of dogs, and 2 designs were used differing only in that one (experimental) had a 3mm transgingival extension, permitting it to be exposed lo the oral cavity from the outset. 12 (3 per animal) non‐submerged implants were placed on I side of 4 beagle dogs and 12 control (submerged) implants were placed contralaterally. All implants were allowed to heal for 6 weeks, after which histological preparations were made. 2 of 12 non‐submerged implants were lost due to post‐operative complications: otherwise, all implants healed uneventfully. Histomorphometric analysis revealed bone‐implant contact, as assessed by absolute bone contact (ABC) and contact length fraction (CLF). to be greater for the submerged design, suggesting that bone healing may be delayed with the non‐submerged approach. As well. at this early stage of healing, for both implant designs, ABC and CLF were significantly greater on proximal than on buccal and lingual aspects.     

Accuracy of implant‐supported prostheses in the edentulous jaw. Analysis of precision of fit between cast gold‐alloy frameworks and master casts by means of a three‐dimensional photogrammetric technique.

Distortions of 15 routine implant‐supported prostheses were measured in relation to the master casts after completion by means of a 3‐dimensional (3‐D) photogrammetric technique. All prostheses were designed as one‐piece gold‐alloy castings with resin teeth. Five of the prostheses were placed in the edentulous maxilla, and the remaining were placed in the lower jaw. Distortion of the cylinders was mostly observed in the horizontal plane (x‐and y‐axis) while the vertical aspect seemed to be more stable. The mean 3‐D center point distortion was 42 (SD 15) and 74 (SD 38)μm for the upper and lower jaws, respectively. The measurements revealed a range of3‐D center point distortion from 16 to 80 and 15 to 165 μm for the different jaws, respectively. The corresponding 3‐D mean angular distortion of the cylinders was 51 (SD 35)μm in lower and 70 (SD 75)μm in the upper jaws. A correlation was found between 3‐D center point distortion and the width as well as the curvature of the implant arch, indicating more displacement the wider and the more curved the arch was. The 3‐D center point distortion was also significantly higher in the upper jaws which could possibly be explained by the curvature of the implant arch and higher numbers of implants in the upper jaws. Further problems with the fit of upper jaw castings could be related to more alloy in the 1 castings and poor alignment of implants.     

Mk II: the self‐tapping Brånemark implant: 5‐year results of a prospective 3‐center study

The 5‐year result of a prospective 3‐center study is presented, comprising103 patients with 288 Mk II self‐tapping and 275 standard implants of the Brånemark System®. Out of 363 mandibular and 200 maxillary fixtures, one Mk II was lost of the lower jaw and 13 of each implant type failed in maxillae during the study period. Cumulative prosthesis stability was 97%. Five patients accounted for more than 85% of the fixture losses. Marginal bone resorption was similar for both implant designs. Apart from the implant failures and one patient exhibiting disturbed nerve sensation of the mental nerve, no major complications were encountered. Overall, this study revealed equal cumulative success rates for standard and Mk II implants after 5‐years of observation. Mandibular implants exhibited greater success rates (100%) for both tested implant types compared to maxillary implants (87%).     

Bone morphogenetic protein‐2 for peri‐implant bone regeneration and osseointegration

Recombinant human bone morphogenetic protein‐2 (rhBMP‐2) induced bone regeneration and osseointegration was evaluated in supra‐alveolar peri‐implant defects in 5 beagle dogs. Alveolar bone was reduced 5 mm in height in mandibular premolar areas and the premolars were extracted. Three 10 mm titanium fixtures were placed 5 mm into each reduced alveolar crest, leaving 5 mm in a supraalveolar position. Alternate quadrants in consecutive animals received a surgical implant consisting of 2 ml rhBMP‐2 (0.43 mg/ml) in a type I bovine collagen carrier, or the carrier alone (control). Fixtures and surgical implants were submerged under the gingival flaps. The healing interval was 16 weeks. Histometric and radiographic evaluations were made. Defect height averaged (*SD) 5.3±O.2 and 5.1±0.2 mm for rhBMP‐2 and control defects, respectively ( P >0.05, n =5, paired, f‐test) Bone regeneration (height) averaged 4.2+1.0 and 0.5±0.3 mm for rhBMP‐2 and control defects, respectively ( P >0.05). Bone regeneration (area) averaged 6.1±6.3 and 0.2±0.2 mm² for rhBMP‐2 and control defects, respectively ( P ±0.05). Osseointegration within the confines of the defect averaged 19.1±10.1% and 8.2±4.6% for rhBMP‐2 and control defects, respectively ( P 0.05). The results suggest that there is a potential for rhBMP‐2 induced bone regeneration and osseointegration in surgical peri‐implant defects.     

Some clinical and radiographical features of submerged and non‐submerged titanium implants. A 5‐year follow‐up study.

The present study reports on the results of a follow‐up examination of patient material, 5 years after the installation of the fixed supraconstruction. The patient group comprised 11 individuals. Briefly, a split‐mouth technique of treatment was used. In the right side of the mandible the traditional 2‐step surgical approach for implant installation was used. In the left jaw quadrant a l‐step surgical procedure was used. A clinical and radiographical examination was performed 5 years after the initial connection of the supra‐construction to the implants. At the 5 year follow‐up examination all 61 implants examined at the 1 month follow‐up were still in service and found to be clinically stable irrespective of the surgical procedure used. Furthermore, the results of the present clinical and radiographical follow‐up study demonstrate that the marginal bone level at implants placed anteriorly in the edentulous mandible and supporting fixed supraconstructions is stable between 18 and 60 months irrespective of whether placed according to a l‐step or 2‐step surgical procedure.     

Experimentally induced peri‐implant mucositis. A clinical study in humans.

The purpose of this study was to compare the clinical and microbiological (microscopic) parameters during the development of experimental gingigivitis and experimental peri-implant mucositis. Twenty partially edentulous patients were treated for moderate to advanced periodontal disease. Following active periodontal therapy consisting of motivation, instruction in oral hygiene practices, scaling and root planing and periodontal surgery where indicated, IMZ oral implants were incorporated in posterior edentulous areas. After 3 months of healing, the prosthetic abutments were connected, and the patients were closely supervised for another 2 months of healing. At this time, baseline data were obtained. Re‐examinations were scheduled at 3 and 6 months. Following this, the patients were asked to refrain from oral hygiene practices for 3 weeks. At all examinations including the end of the period of no oral hygiene, the following clinical parameters were obtained: Plaque Index, Gingival Index and Sulcus Bleeding Index, all modified by Mombelli et al. (1987) probing pocket depths and recession in mm. Furthermore, submucosal/subgingival plaque samples were obtained and analyzed using phase contrast microscopy. At the end of the 3‐week period of plaque accumulation: optimal oral hygiene was reinstituted. There were no statistically significant differences between the mean values of all parameters at implant compared to tooth sites at any observation periods. The period of no oral hygiene demonstrated a similar cause‐effect relationship between the accumulation of bacteria1 plaque and the development of peri-implant mucositis as established for the gingival units by the experimental gingivitis model.