Marginal bone reaction to oral implants: a prospective comparative study of Astra Tech and Brånemark System implants

Abstract: In earlier studies of Astra Tech and Brånemark System implants, high survival rates and small marginal bone changes have been demonstrated. The aim of this study was to compare the two systems, primarily with regard to marginal bone changes, but also with regard to other clinical variables of interest. The present paper describes the results after three years. Sixty‐six patients were included in the study and randomly assigned to treatment with Astra Tech implants (n=184) or Brånemark System implants (n=187). The marginal bone level was radiographically examined at fixture insertion, at abutment connection, at baseline (delivery of the prosthetic construction) and at 1‐ and 3‐year follow‐up examinations. Between fixture insertion and the baseline examination, the pattern of marginal bone resorption differed between the two systems. However, there was no significant marginal bone change between baseline and the 1‐year examination or between the 1‐ and 3‐year examinations. Nor were there any differences between the systems. The mean bone loss in the upper jaw between BL (baseline) and 3 years was 0.2±0.3 mm for Astra Tech implants and 0.2±0.1 mm for Brånemark System implants. The corresponding figures for the lower jaw were 0.3±0.2 mm and 0.2±0.1 mm. The survival rate of Astra Tech implants was significantly higher (98.9%) than for Brånemark System implants (95.2%). However, five of the nine implant losses in the Brånemark group occurred in one patient. For that reason, this result must be interpreted with caution. The number of patients with implant losses did not differ significantly between the systems. Few complications were recorded up to 3 years.     

Immediate functional loading of Brånemark single tooth implants. An 18 months' clinical pilot follow-up study

A clinical and radiographical study was performed to evaluate the treatment outcome of single tooth replacements with artificial crowns retained to implants installed according to a 1‐stage surgical procedure and immediate loading (Experimental Group=EG) in comparison to the original 2‐stage concept (Control Group=CG). The EG comprised 14 patients (=14 implants) and the CG comprised 8 patients (=8 implants), all with single tooth losses anterior to the molars. Beyond the non‐smoking criterion the following criteria were adopted: i) the amount of bone had to allow for installation of a fixture with a minimum length of 13 mm and ?=3.75 mm, ii) the jaw relationship had to allow for bilateral occlusal stability, iii) the patients should be judged to be non‐bruxers, and iv) the patients had to be available for the follow‐up and maintenance programme. In the EG a temporary crown was connected to the implant within 24 h following fixture installation. Six months later this crown was replaced with a permanent one. In the CG the surgical and prosthetic treatment followed the standard protocol. Out of the 14 fixtures in the EG 2 were lost up to 5 months in function and were subsequently removed. All remaining 12 implants were stable at every subsequent follow‐up examination. No fixture losses were recorded in the CG and all implants in this group were stable at the follow‐ups. At the 6‐month observation interval all the participating 20 patients were radiographically examined, an examination that was repeated at the 18‐month follow‐up. The analysis of the radiographs from the EG as well as from the CG disclosed that during the 12‐month observation period the mean change of bone support was about 0.1 mm. Further studies, designed as controlled multicenter ones, have to be performed before the results of this pilot study can be recommended for more general use.     

Astra Tech and Brånemark system implants: a 5-year prospective study of marginal bone reactions

Abstract: This paper describes the 5‐year results of a comparative study between Astra Tech and Brånemark system implants. The aim was to compare the systems primarily with regard to bone level changes, and also with regard to other variables of interest. Sixty‐six patients with edentulous jaws were included in the study. Randomisation schedules were used to allocate the patients to the two implant systems. 184 Astra Tech implants with a titanium‐blasted surface and 187 Brånemark implants with a turned surface were used. The implants were inserted with a two‐stage technique and the insertion followed the routines for the respective implant system. All patients were provided with full‐arch fixed bridges. All patients were followed up with clinical and radiographic examinations from fixture insertion to the 5‐year follow‐up. The total mean bone level change in the upper jaw between fixture insertion and the 5‐year examination was ?1.74±0.45 mm at the Astra implants and ?1.98±0.21 at the Brånemark implants. The corresponding values for the lower jaw were ?1.06±0.19 for Astra and ?1.38±0.17 for Brånemark. The major postoperative changes of the marginal bone level took place between fixture insertion and baseline. During this period, there was also a different pattern of bone remodelling between the implant systems. Between baseline (prosthesis connection) and the 5‐year examination, the marginal bone level changes were small, with no difference between the implant systems. The implant stability was examined with the supraconstructions removed. At the 5‐year examination, the survival rate for Astra Tech implants was 98.4% and for the Brånemark implants it was 94.6%. The difference was not statistically significant.     

A study of 275 retrieved Brånemark oral implants

The aim of this report was to describe the bone tissue response to Br?nemark oral implants retrieved from patients. The material consisted of consecutively received Br?nemark threaded oral implants and related patient data provided by clinicians. The implant samples were processed into undecalcified sections for evaluation under the light microscope. The analysis demonstrated a lower percentage of bone-to-implant contact for the unloaded implants as compared to the loaded implants. When the threads were divided into four different regions, the loaded implants had a lower percentage of bone-contacting length at the thread top as compared to the other three regions.     

A controlled clinical trial of implant-retained mandibular overdentures; five-years' results of clinical aspects and aftercare of IMZ implants and Brånemark implants

The aim of this prospective randomized controlled clinical trial was to evaluate a set of clinical items and prosthetic aftercare of edentulous patients with a mandibular overdenture retained by 2 IMZ implants or 2 Brånemark implants during a 5‐years' period. Patients were allocated to the IMZ group (n=29) or the Brånemark group (n=32) by a computerized balancing method. In the IMZ group 4 implants were lost during the 5‐years' follow‐up (survival rate: 93%). In the Brånemark group 9 implants were lost (survival rate: 86%). All patients were re‐operated successfully. Multiple prosthetic revisions were necessary in both groups, especially the precision attachment system in the overdenture was subject to frequent fracture or loosening. From this study can be concluded that there is no difference in clinical state, radiographical state, survival rate and clinical implant performance between the IMZ implant system and the Brånemark implant system supporting an overdenture on 2 implants after 5 years of follow‐up.     

A controlled clinical trial of implant-retained mandibular overdentures: 10 years' results of clinical aspects and aftercare of IMZ implants and Brånemark implants

Abstract: The aim of this prospective randomized controlled clinical trial was to evaluate the clinical outcomes and prosthetic aftercare of edentulous patients with a mandibular overdenture retained by two IMZ implants or two Brånemark implants during a 10‐year period. Patients were allocated to the IMZ group (n=29) or the Brånemark group (n=32) by a computerized balancing method. In the IMZ group, four implants were lost during the 10‐year follow‐up (survival rate: 93%). In the Brånemark group, nine implants were lost (survival rate: 86%). All patients were re‐operated successfully. Multiple prosthetic revisions were necessary in both groups; especially the precision attachment system in the overdenture (23% of the total number of revisions) and the denture base and teeth (26% of the total number of revisions) were subject to frequent fracture. From this study, it can be concluded that both the IMZ implant and the Brånemark implant systems supporting an overdenture are functioning well after 10 years of follow‐up. There are no indications of a worsening of clinical or radiographical state after 10 years.     

Astra Tech and Brånemark System implants: a prospective 5-year comparative study. Results after one year

Background: Endosseous dental implants are used frequently, and many implant systems are available. The scientific documentation of the implant system presents a great variation, and it is often difficult to compare studies of different systems. Purpose: The aim of this study was to compare two Swedish implant systems (Astra Tech and Brånemark System± implants), in a prospective randomized study. Materials and Methods: Sixty-six patients were equally distributed between the two implant systems; 184 Astra Tech and 187 Brånemark System implants were used. The patients have been followed annually with clinical and radiographic examinations. The results after 1 year are reported. Results: The abutment procedure was found to be easier and less time-consuming with Astra Tech than with Brånemark implants. The operation times in minutes (mean ± SEM) were for the respective implant 35 ± 4.0 and 51 ± 4.8 in the maxilla and 32 ± 3.8 and 43 ± 2.4 in the mandible. The differences in both cases were significant: p <.02 and p <.05, respectively. The failure rate for Astra Tech implants was 0.5% and for Brånemark implants 4.3%. The difference was significant (p <.05); however, taking into account that five of the eight implant losses in the Brånemark implant group occurred in one patient, an intraindividual correlation cannot be excluded. Therefore, this result should be interpreted with caution. The marginal bone level changes were examined already from the fixture installation. The major bone loss was found between fixture installation and baseline. This bone loss was several times greater than the bone loss between the baseline and the 1-year follow-up. The total bone loss during the observation period did not differ significantly between the systems, but they had different resorption patterns. The bone loss in the upper jaw between baseline and 1-year follow-up was 0.22 ± 0.14 and 0.03 ± 0.09 mm for the Astra Tech and Brånemark implants, respectively. In the lower jaw, the loss was -0.31 for both systems. The frequency of plaque accumulation and bleeding on probing did not differ between the implant systems. Conclusions: Abutment connection with Astra Tech implants was simpler than the corresponding surgery with Brånemark System implants and the survival rate of Astra Tech implants was higher than that of Brånemark system implants.     

Brånemark System Wide Platform implants for single molar replacement: clinical evaluation of prospective and retrospective materials

Background: The use of oral implants for single tooth replacement has become a predictable treatment modality. As single tooth loss is most common in posterior areas of the jaws, the use of the protocol is of specific interest in those regions. New implant designs aimed at this purpose have also been introduced. Purpose: The aim of the study was to present the outcomes for wide diameter implant treatment when being used in posterior areas of the jaws. Materials and Methods: This paper presents the 3‐year results of a prospective multicenter study (three clinics; n = 38 implants) and the 1‐year results from a retrospective multicenter study (two clinics; n = 20 implants) on wide diameter implants for single molar replacement. Based on the hypothesis that dense bone in posterior mandibles would benefit from careful surgery and longer remodeling time, the influences of surgical technique and healing time on implant success and bone resorption were particularly addressed. Results: The outcome demonstrated a good predictability for Brånemark System® Wide Platform implants, at least short term, when used as single molar support (prospective group cumulative success rate [CSR] = 92% after 3 years; retrospective group CSR = 95% after 1 year). The increased mechanical strength of the wide platform implant/abutment complex also turned out to be important for mechanical stability. Conclusions: The study indicated that it was important to carefully perform surgery in posterior mandibles in order to preserve and optimally use the existing dense bone. It was suggested that from bone healing and remodeling aspects, posterior mandibles may be more demanding to handle than corresponding areas of maxillae.     

Radiographic follow-up analysis of Brånemark dental implants

Radiography plays an important role in clinical routine practice and in research projects evaluating dental implants, among them Br?nemark System. Presence of a peri-implant radiolucency has been used in studies as a criterion for implant failure without knowledge of its diagnostic accuracy. More precise determination, whether implants are osseointegrated or not, can be achieved if prosthetic constructions are detached to test implant stability. Such an approach is time-consuming and cumbersome. Hence, the accuracy in radiographic diagnosis of clinical instability has to be evaluated. Further, radiography is a commonly used diagnostic tool for monitoring marginal bone loss. Little is known about the observer variation. Long-term follow-up studies have shown conventional implant therapy to be a reliable procedure with few complications and minor average bone loss. Lately, studies have shown progressive bone loss in higher frequencies. When testing accuracy in diagnosis of clinical instability in intra-oral radiographs, it was found to be as good as of many other radiographic procedures, e.g. caries diagnosis. Possibility of predicting instability, however, can be low in populations with low prevalence of implants showing loss of osseointegration. Intra-observer variation was found to be the largest source of the total variation when studying inter- and intra-observer variability in radiographic bone level assessments. The number of radiographs in which individual implants were displayed had an influenced on intra-observer variation, while radiographic density and increased bone loss influenced the total inter-observer variation. Reliability can be improved by multiple readings by one observer or, even better, by letting several observers make several, independent readings, this limits the effect of a single observer who may be an outlier. Marginal bone level was assessed in 640 patients with a radiographic follow-up of > or = 5 years. The number of implants with a mean bone level of > or = 3 mm below the fixture-abutment connection increased from 2.8% at prosthesis insertion to 17.2% after 15 years. Implant-based bone loss was as a mean 0.8 mm (SD 0.8) after 5 years, followed by only minor average changes. Mean bone loss on patient level followed a similar pattern. Disregarding of follow-up time, altogether 183 implants showed a bone loss > or = 3 mm from prosthesis insertion to last examination, most of them in totally edentulous patients. Seventy of the 183 implants were found in 19 of the 107 patients. Hence, there seems to be a clustering effect. For the entire group of patients significantly larger bone loss was found the older the patient was at surgery and for lower jaw implants. Placement of the implant within the prosthetic construction, regardless of jaw-type, was found to be a predictor of a bone loss > or = 2 mm with minor bone loss around implants placed in an end position. Other predictors were age and jaw-type. The number of intra-oral radiographs per examination, and more importantly, radiographic examinations can be reduced without jeopardizing good clinical management, a statement valid also for Br?nemark implants with advanced bone loss. To conclude, conventional implant treatment can still be regarded as a reliable and safe procedure.     

A prospective clinical evaluation of different single-tooth restoration designs on osseointegrated implants. A 3-year follow-up of Brånemark implants

Since single-tooth implant restorations were introduced 12 years ago (Jemt 1986), there has been continuous development both in the technical design and the aesthetic outcome of the treatment. In order to ensure high quality in single-tooth implant treatments a clinical follow-up study was carried out on patients treated with modifications to the original regimen. In this study 69 consecutive patients were provided with 80 single-tooth implant restorations. The patients were followed for 3 years. There was continuous development of the prosthetic design during the time of the study, allowing us to analyse possible prognostic differences for the different prosthetic treatments. This study confirms earlier reports which describe the single-tooth implant treatment as a safe method with few surgical complications and minimal marginal bone loss. Only 1 implant was lost during the follow-up period and the average marginal bone loss was 0.48 mm over the 3-year follow-up period. Crowns veneered with acrylic and with gold casted directly to the abutments, screwed onto the implants, led to recurring prosthetic complications and gave an appearance of rapid ageing. The first generation of crowns made following the Cera-One design, sometimes produced a gap between the crown and the abutment associated with significant marginal bone loss during the first year. Few surgical or prosthetic complications were noted with cemented all-ceramic constructions, although the number of these crowns in this study was limited.     

A comparison between insertion torque and resonance frequency in the assessment of torque capacity and primary stability of Brånemark system implants

summary The aim of this study was to determine primary stability and insertion torque of Brånemark System implants placed in the anterior mandible, and to evaluate a possible correlation between primary stability and insertion torque. Thirty edentulous patients were treated with 60 Brånemark System implants using a one‐stage technique. The insertion torque values of all implants were recorded with the Osseocare equipment. Immediately after implant placement, each implant was connected to the transducer of an Osstell machine to measure the primary implant stability. The average insertion torque and resonance frequency values were 41·5 ± 5·8 and 74·1 ± 3·8 for 30 implants. The correlation between insertion torque and resonance frequency values indicated a statistical significance (P < 0·001). The difference between mean insertion torque values for female and male patients was statistically significant (P < 0·001). No significant difference (P > 0·05) was found between younger and older patients with mean insertion torque values of 43·1 ± 4·7 and 40·1 ± 6·5 respectively. The results of this study showed a strong correlation between the primary stability and insertion torque values of Brånemark System TiUnite MKIII implants at the time of implant placement.     

Early functional loading of Brånemark dental implants: 5-year clinical follow-up study

Background: Short‐term clinical studies have indicated the possibility of one‐stage surgery and early loading of machined titanium implants. However, long‐term data comparing the outcome to the conventional two‐stage technique are missing. Purpose: A clinical and radiographic study was performed to compare the outcome of oral rehabilitation of the endentulous mandible by fixed suprastructures connected to implants installed according to either (1) a one‐stage surgical procedure and early loading (experimental group ‐ EG) or (2) the original two‐stage concept (reference group ‐ RG). The EG and RG comprised 16 and 11 subjects, respectively. Materials and Methods: The following specific inclusion criterion were adopted: (1) all patients had to consider themselves to be in good general health, (2) the amount of bone had to enable the installation of five to six, at least 10‐mm long fixtures (Mk II fixtures; Nobel Biocare AB, Göteborg, Sweden) between the mental foramina, and (3) the patients had to be available for the follow‐up and maintenance program. A total of 88 implants were placed in the EG compared to 30 in the RG. In the EG, fixed appliances were connected to the implants within 20 days following implant installation while the fixed appliances in the RG were connected about 4 months following fixture installation. At delivery of the suprastructures, all patients were radiographically examined, an examination that was repeated at the 18‐ and 60‐month follow‐ups. Results: The analysis of the radiographs from the EG disclosed that during the observation period, between 18 and 60 months, the mean loss of bone support amounted to 0.2 mm (SD = 0.4). The corresponding value observed in the RG was 0.0 mm (SD = 0.5). During the 60‐month observation period, no fixture was lost in any of the two groups examined. The implants under study as well as those in the reference material were at all observation intervals found to be clinically stable. Conclusions: This clinical study demonstrated that it is, at least based on a 5‐year observation period, possible to successfully load via a permanent fixed rigid cross‐arch suprastructure titanium dental implants soon after installation. However, such a treatment approach has to be strictly limited to the interforamina area of the endentulous mandible. Furthermore, the bone resorption was found to be within the same range around such implants as around implants installed and loaded according to the original two‐stage protocal.     

A retrospective evaluation of 259 single-tooth replacements by the use of Brånemark implants

PURPOSE: The main purpose of this retrospective study was to investigate the clinical outcome of the treatment with 259 consecutively placed Br?nemark system implant-supported single crowns. MATERIALS AND METHODS: There were 259 implants placed in 183 patients with a mean age of 29.8 years; 230 (89%) were placed in the maxilla and 29 (11%) were placed in the mandible. Of the prosthetic restorations, 165 were all-ceramic (68%), 79 were metal-ceramic (31%), and 4 were gold-acrylic (1%). The observation period ranged from 1 to 9 years. RESULTS: A total of 9 patients (10 implants) was lost to follow-up. There were 3 implant failures registered, one before loading and one during the first year in function; one implant fractured after 6 years in service, giving a cumulative success rate for implants of 98.3%. A total of 8 crowns was remade following prosthetic complications; otherwise, the frequency of adverse events was low. The bone loss was of the same magnitude as in other studies on Br?nemark implants as support for single crowns. In general, the soft tissue conditions around the restorations were healthy and comparable to those of the patients' natural teeth. CONCLUSION: This study confirms the favorable results presented in other studies on Br?nemark implants to support single-tooth restorations.     

Strength and marginal fit of full and partial porcelain crowns on Brånemark implants

The aim of the present study was to evaluate strength and marginal fit of different designed single crowns screwed on titanium implants (Brånemark) without the usage of any abutment. Seven test groups with 10 specimens each (standardized maxillary central incisor crowns) were fabricated of Empress (staining/veneering technique), metal‐based Empress (staining/veneering technique), metal‐based In‐Ceram and metal ceramic (with/without cervical porcelain margin). The marginal fit of 5 specimens of each group was evaluated (SEM‐Analysis) and the crowns were incisally loaded at a 30° angle in a Zwick testing machine until fracture. The 5 remaining specimens underwent a marginal evaluation (SEM‐analyses) before and after thermo‐mechanical stressing (tms) and were loaded in the Zwick testing machine as well. All Empress ceramic crowns without metal reinforcement fractured during fixing procedure on the implant (32 N cm). The gap medians of the fixed crowns ranged from 11 μm (metal ceramic crowns) to 34 μm (metal ceramic crowns with porcelain margin). No significant differences in gap width were observed before and after tms. In the strength analyses screw‐binding forces (SBF) of about 135 N were registered in all test groups. Fracture failure forces (FFF) reached up to 280 N. The indication of the crown designs presented in this study is limited in clinical use because of low stability and esthetics.     

Early functional loading using Brånemark dental implants

The present review article discusses the one- and two-stage surgical protocol for dental implant placement as well as the critical amount of micromotion at the bone-implant interface to obtain proper osseointegration. The relevant literature supporting the hypothesis that "splinting of individual implants as soon as possible following installation via a rigid fixed device will most likely decrease the micromotion at the bone-implant interface thus facilitating proper bone healing (osseointegration)" is reported. As a consequence of this approach, the treatment period can be significantly reduced. Finally, the importance of an objective evaluation of the bone quality and initial implant stability is highlighted. The information thus obtained via tools already available will facilitate the decision as to whether to load implants immediately, early, or late, and the term "individual functional loading" is coined.     

Immediate functional loading of Brånemark dental implants. An 18-month clinical follow-up study

A clinical and radiographical study was performed to compare the out-come of oral rehabilitation in the edentulous mandible by fixed supra-constructions connected to implants installed according to either i) a l-stage surgical procedure and immediate loading (Experimental Group -EG), or ii) the original 2-stage concept (Reference Group - RG). The EG comprised 16 subjects with edentulous mandibles. Beyond the non-smoking criteria the following specific inclusion criteria were adopted: i) all patients had to consider themselves to be in good general health, ii( the amount of bone had to enable the installation of 5-6, at least 10 mm long fixtures to be bicortically anchored (Mk II fixtures; Nobel Biocare AB, Goteborg, Sweden) between the mental foramina, and iii) the patients had to be available for the follow-up and maintenance programme. A total of 88 implants were placed in the EG (16 patients) compared to 30 in the RG (11 patients). In the EG, fixed appliances were connected to the implants within 20 days following implant installation while the fixed appliances in the RG were connected about 4 months following fixture installation. At the time for delivery of the supraconstructions all 27 patients were radiographically examined, an examination that was repeated at the 18-month follow-up. The analysis of the radiographs from the EG disclosed that during the 18-month observation period the mean loss of bone support amounted to 0.4 mm. The corresponding value observed in the RG was 0.8 mm. During the 18-month observation period no fixture was lost in any of the 2 groups examined. The implants under study as well as those in the reference material were at all observation intervals found to be clinically stable. The present clinical study demonstrated that it is, at least based on an 18-month observation period, possible to successfully load titanium dental implants immediately following installation via a permanent fixed rigid cross-arch supraconstruction. However, such a treatment approach has so far to be strictly limited to the interforamina area of the edentulous mandible.     

Tapered implants in jaws with soft bone quality: a clinical and radiographic 1-year study of the Brånemark System Mark IV fixture

Background: The survival rate of oral implants in soft‐quality bone has been demonstrated to be inferior to that of implants inserted in good‐quality bone. A possible way to increase the survival rate in soft‐quality bone may be to use a tapered implant. Such an implant has been developed and manufactured by Nobel Biocare AB, Gothenburg, Sweden. So far, there have been only a few publications regarding this implant. Purpose: The aim of the study was to compare the outcome of using the tapered Branemark System Mark IV fixture with the outcome of using earlier Brånemark fixtures in a controlled prospective study. Materials and Methods: The study was performed as a multicenter study including seven specialist centers. The material consisted of 40 patients in need of implant‐supported bridges in the maxilla. Twenty‐five patients belonged to the test group, in which the tapered Mark IV implants were inserted, and 15 patients belonged to the control group, in which Branemark Standard or Mark II implants were used. The patients were allocated to the test group or the control group according to randomization schedules. The implants were inserted according to the guidelines for Branemark implants. A two‐stage surgical protocol was used, and abutment connection was made 6 months after fixture insertion. The test group comprised 97 Mark IV implants, and the control group made up 92 implants. The prosthetic procedure followed the guidelines for Brånemark implants, and all patients were provided with full fixed maxillary bridges. The patients were followed up with clinical and radiographie records for 1 year after loading. Results: The survival rate was 96.9% for the Mark IV implants and 98.9% for the control implants. There was no significant difference between the two groups. There was a mean marginal bone loss of 0.2 mm during the observation period, and there was no difference between test implants and control implants. Conclusions: With regard to survival rate and marginal bone level changes, no differences could be demonstrated between the Mark IV tapered implant and the Brånemark implants used earlier. However, compared with earlier results of Brånemark implants in soft‐quality bone, the Mark IV implant demonstrated an improved survival rate.     

Turned Brånemark System implants in wide and narrow edentulous maxillae: a retrospective clinical study

Background: The available jawbone volume is regarded as one of the most important factors when assessing the prognosis of oral implants in the rehabilitation of the edentulous maxilla. Purpose: The aim of the current investigation was to retrospectively evaluate and compare the outcome of implants placed in edentulous maxillae with either wide or narrow jaw shapes. The marginal bone loss and implant cumulative survival rates (CSRs) were calculated and analyzed with special reference to smoking habits. Materials and Methods: The study included 75 individuals with edentulous maxillae, of which 33 patients exhibited wide (group A) and 42 patients exhibited narrow jaw shapes (group B). A total of 506 turned Brånemark System® (Nobel Biocare AB, Göteborg, Sweden) implants were inserted (226 in group A and 279 in group B) and followed clinically up to 7 years. Smoking habits were recorded. Radiographs were obtained at connection of prostheses, and at the 1‐ and 5‐year follow‐up visit. The marginal bone loss was calculated for the groups and analyzed using t‐test. Results: Twenty‐eight implants were lost during the study period, revealing implant CSRs at 7 years of 94.6% (11/226) and 93.6% (17/279) for wide and narrow crests, respectively. No difference in marginal bone loss was seen between the two groups, although a trend toward more bone loss was recorded for patients with wide crests. Smoking habits were more common in group A (45%) than in group B (31%). During the first year of function, smokers lost significantly more marginal bone than nonsmokers (p = .0447), albeit this difference did not prevail (p > .05) at the end of the study period. Conclusions: The implant CSRs at 7 years were equally good for the two groups of patients with various jaw shapes. Initially, smokers showed significantly more marginal bone loss than nonsmokers.