Influence of a single preoperative dose of antibiotics on the early implant failure rate. A randomized clinical trial.

BACKGROUND: The use of a preoperative single dose of antibiotics as routine in conjunction with implant surgery is controversial, in light of the unclear effect on early implant failure rate and risk for development of resistant bacterial strains. PURPOSE: This randomized clinical trial compared the early implant failure rates in two different patient cohorts: One group receiving a single dose of preoperative antibiotics (AB group) and one group receiving no antibiotics, prior to implant surgery (noAB group). MATERIALS AND METHODS: Patients were referred for treatment at four specialist clinics in the county council of West Sweden, Vastra Gotaland and randomly assigned into one of the two groups. A total of 447 patients received 963 implants were included in the study. Of these, 223 patients (535 implants) belonged to the AB-group and 224 patients (428 implants) to the noAB-group. Four commercial implant brands were utilized, albeit one system was only represented with four implants. The outcome was evaluated after 4 months using either a one-stage or two-stage procedure. The surgical procedures were performed by experienced implant surgeons and the surgical protocol for implant placement follows standard. Failure was defined as removal of an implant for any reason. The study outcomes were statistically analyzed to evaluate the differences between the two groups. RESULTS: Twelve implants failed in 11 patients for the AB group, and 32 implants failed in 29 patients for the noAB group. Preoperative antibiotics, AB group, had significantly (P < 0.0011) lower implant failure 2.2% compared to 7.5% in the noAB group analyzed on implant level adjusted for dependence within patients, OR = 0.30, 95% confidence interval (0.14-0.62). CONCLUSION: Administration of a single dose of antibiotics in conjunction with implant placement surgery resulted in a statistically significant lower early implant failure rate compared to when no antibiotics were used.

A randomized, controlled, clinical study on a new titanium oxide abutment surface for improved healing and soft tissue health.

BACKGROUND: A newly developed, anodized titanium oxide surface containing anatase has been reported to have antimicrobial properties that could reduce bacterial adherence to abutments. PURPOSE: To investigate if abutments with the anodized surface improve healing and soft tissue health in a randomized controlled study. MATERIALS AND METHODS: Test abutments with a nanostructured anodized surface were compared with control machined titanium abutments. In total, 35 subjects each received a pair of test and control abutments. The primary endpoint was reduction of biofilm formation at test abutments at the 6-week follow-up. Secondary endpoints included several soft tissue assessments. qPCR for gene markers was used to indirectly evaluate healing and soft tissue health. RESULTS: No significant differences in biofilm formation were observed between test and control abutments, but soft tissue bleeding upon abutment removal was significantly lower for test abutments compared with control abutments (P = 0.006) at 6 weeks. Keratinized mucosa height was significantly greater at test abutments compared with control abutments at the 6-week, 6-month, and 2-year follow-ups. Significant gene expression differences indicated differences in healing and tissue remodeling. CONCLUSIONS: Abutments with an anodized and nanostructured surface compared with a conventional, machined titanium surface had no significant effect on bacterial colonization and proteolytic activity but were associated with better soft tissue outcomes such as a lower bleeding index at abutment removal and consistently greater height of keratinized mucosa throughout the 2-year follow-up, suggesting improved surface-dependent peri-implant healing and soft tissue health.

A prospective study on single tooth reconstructions using parallel walled implants with internal connection (NobelParallel CC) and abutments with angulated screw channels (ASC).

BACKGROUND: A new implant design was launched in 2015 with internal connection allowing for placement of abutments with angulated screw channels. Such devices may eliminate the use of nonauthentic components, which may present with poor fit and jeopardize the construction. It may also eliminate the use of cemented single-crowns with the risk for excessive cement to cause marginal bone destruction. PURPOSE: To evaluate the outcome of a straight-walled implant with conical connection (NobelParallel CC), when used in the single-tooth situation of the anterior maxilla. Further, to elucidate the need for an abutment with angulated screw channel (ASC). MATERIALS AND METHODS: Patients referred for both implant surgery and prosthetics to rehabilitate missing single maxillary incisors/canines. Implants were placed according to a two-staged surgical procedure. Patients were followed up to delivery of prosthetic crowns with the purpose to extend the study up to 1-, 3-, and 5-year follow up. Registrations of implant survival, marginal bone level measurements, hard/soft tissue complications, and the incidence of ASC to avoid the use of nonauthentic components or crown cementation, were performed at the end of the study. RESULTS: A total of 47 patients were included in the current investigation. One patient deceased during the study period. In all 51 implants were inserted, of which 14 implant sites were bone augmented either prior to implant placement or in connection with the insertion procedure. Further, four remaining teeth were extracted in the region of interest during implant placement. One implant presented with infection and mobility at abutment connection and was consequently removed. Implant survival rate was 98.0%. Mean marginal bone level at crown placement was 0.41 mm (SD = 0.45 mm) and the corresponding measurements at 1 year for 22 implants revealed a marginal bone resorption of 0.41 mm (SD = 0.36 mm). Abutments with angulated screw channels were used in 42/49 sites. CONCLUSION: The NobelParallel CC implant seemed to work well together with the ASC abutment. No major complications were noted.

Immediate provisionalization in the esthetic zone: 1-year interim results from a prospective single-cohort multicenter study evaluating 3.0-mm-diameter tapered implants.

OBJECTIVES: The aim of this interim analysis of a 5-year prospective multicenter study is to evaluate clinical and radiological performance of immediately provisionalized 3.0-mm-diameter tapered implants. MATERIALS AND METHODS: Patients needing implant rehabilitation of maxillary lateral incisors or mandibular lateral and central incisors were treated with 3.0-mm-diameter implants placed in extraction or healed sites and immediately provisionalized. Clinical and radiographic examinations were performed at implant insertion, 6 months thereafter, and are ongoing. Marginal bone levels and changes, complications, the papilla, plaque, and bleeding indices, and the pink esthetic score (PES) were evaluated at each follow-up visit. RESULTS: Of 112 enrolled patients, 77 patients (91 implants) met the inclusion criteria. Seventy-one patients with 82 implants completed the 1-year follow-up. Three implants failed yielding a CSR of 96.7%. All failures occurred within the first 3 months after implant insertion. Marginal bone level changes from insertion to 6 months was - 0.57 ± 1.30 mm (n = 75) and from insertion to 12 months - 0.25 ± 1.38 mm (n = 72). Fifteen non-serious complications were recorded. Papilla index score and PES improved at the 1-year follow-up. Plaque formation and bleeding-on-probing showed no statistically significant differences between the 6-month and the 1-year visit. CONCLUSIONS: This 1-year analysis demonstrated high survival, stable bone levels, and healthy soft tissue with 3.0-mm-diameter implants. CLINICAL IMPLICATIONS: Narrow diameter implants are a safe and predictable treatment option in patients with limited bone volume and/or limited interdental space and eligible for immediate loading protocols.

Bone augmentation for single tooth implants: A review of the literature.

AIM: To analyse data on bone augmentation at single-tooth implants with regard to the type of graft materials, the stability of grafts over time, reported time span towards implant placement, implant survival rates, implant marginal bone maintenance and possible complications. MATERIAL AND METHODS: A literature review resulted in 585 titles after exclusion of duplicates. Analyses of article titles and abstracts reduced the number to 93 studies, which were subsequently full-text analysed. After the final selection, a total of 24 studies were included, of which 13 reported on single implants and horizontal/vertical augmentation (onlay), 10 focused on single implants and sinus augmentation (inlay), and one study presented the outcome of single implants and distraction osteogenesis. RESULTS: All bone materials, i.e. autografts, allografts, xenografts, and alloplasts, were used with comparable satisfactory results, allowing for placement of 7 to 10 mm-long implants. Stability of bone graft volume over time was sparsely documented. Some onlay autografts tended to resorb early i.e. prior to implant placement, but minor bone resorption was also seen for other grafts over time. A continuous but small bone resorption of inlay autografts and alloplasts was seen over time for the few sites recorded. A staged approach predominated for the onlay grafts, with implants placed 3 to 6 months post-grafting, and overall a majority of these implants (347/363) were submerged. For the inlay graft procedures almost all implants were immediately inserted at the time of grafting, and the majority of these implants (253/256) were submerged. A total of five and two implant failures were registered during the various study periods for the onlays and inlays, respectively. Marginal bone conditions, around implants in grafted sites, were comparable to what has generally been reported for non-grafted sites. CONCLUSIONS: Bone augmentation for the single-tooth implant is a viable treatment option with predictable graft and implant outcomes.

Early Implant Failures Related to Individual Surgeons: An Analysis Covering 11,074 Operations Performed during 28 Years.

BACKGROUND: Compared with knowledge on patient and implant component factors, little knowledge is available on surgeons' role in early implant failures. PURPOSE: To report incidence of early implant failures related to total number of operations performed by individual surgeons. MATERIALS AND METHODS: Early implant failures (≤1 year of implant prosthesis function) were reported after a total of 11,074 implant operations at one specialist clinic during 28 years of surgery. Altogether, 8,808 individual patients were treated by 23 different dentists, of whom 21 surgeons were specialists in oral surgery or periodontology. Recorded failures were related to total numbers of performed operations per surgeon, followed by statistical comparisons (χ2 ) between surgeons with regard to type of treated jaw and implant surface. RESULTS: Altogether, 616 operations were recorded with early implant failures (5.6%), most often observed in edentulous upper jaws after placing implants with a turned surface (p < .05). Significant differences between surgeons, gender of surgeon, type of treated jaws by the surgeon, and implant surface used by the surgeon could be observed (p < .05). CONCLUSIONS: Early implant failures are complex, multifactorial problems associated with many aspects in the surgical procedure. A stochastic variation of failures for individual surgeons could be observed over the years. Different levels of failure rate could be observed between the surgeons, occasionally reaching significant levels as a total or for different jaw situations (p < .05). The surgeons reduced their failure rates when using implants with moderately rough surfaces (p < .5), but the relationship of failure rate between the surgeons was maintained.

Clinical and radiographic outcomes of lateral sinus floor elevation: a retrospective study.

The aim of this retrospective study was to evaluate the clinical and radiographic outcomes of lateral sinus floor elevation (LSFE). A total of 347 medium rough surface implants were placed in both xenogenic bone and natural bone in 103 patients. A two-stage surgical technique was performed with a lateral window approach followed by a healing period of 9 months prior to implant placement. Patients were analysed with regard to pre- and post-augmentation bone height data (Group A), levels of mar- ginal bone (Group B) and implant survival rates/complications. A total of 6 implants were lost in the present investigation, of which two were still osseoin- tegrated, albeit mechanically damaged.The implant survival rate was 99.0% considering those engaging BioOss, and the corresponding figure for implants placed in natural bone was 96.2%. The average follow-up time was 2.5 years.The mean preoperative bone height was 3.8 mm and the mean postoperative bone height was 13.7 mm. It may be advocated that preoperative bone heights exceeding 7 mm are not indicative of LSFE treatment and that preoperative bone heights of 4-7 mm may imply alternative treatment options. A group of subjects, corresponding to 16.5%- of the patient material, had some sort of postoperative complication. One may conclude that LSFE is a predictable and safe treatment procedure, with a high implant survival rate. LSFE resulted in gained bone height in the range of 10 mm.

A controlled, cross-sectional exploratory study on markers for the plasminogen system and inflammation in crevicular fluid samples from healthy, mucositis and peri-implantitis sites.

PURPOSE: To investigate expression of gene markers for the plasminogen system, inflammation, and bone resorption/remodelling in peri-implant crevicular fluid samples from healthy subjects, subjects with mucositis and subjects with peri-implantitis. A possible inhibitory effect of suppuration on the analysis of gene expression in samples from subjects with peri-implantitis was also analysed. MATERIALS AND METHODS: Peri-implant crevicular fluid (PICF) was sampled from 25 healthy subjects (H), 25 subjects with mucositis (M) and 25 subjects with peri-implantitis (P) using paper points and suction tips. The samples were analysed by quantitative polymerase chain reaction (qPCR). The following biomarkers associated with the plasminogen system, inflammation and bone resorption/ remodelling were investigated: interleukin-1 beta (IL-1ß), interleukin 8 (IL-8), tissue plasminogen activator (tPA), plasminogen activator inhibitor 2 (PAI-2), tartrate-resistant acid phosphatase (TRAP) and cathepsin K (CatK). RESULTS: IL-1ß and IL-8 were significantly upregulated in the P group, and tPA and PAI-2 were significantly upregulated in the M group. These four genetic markers were oppositely regulated in samples from the subjects in the mucositis compared with the peri-implantitis group. TRAP and CatK showed no differences between the groups. The presence of suppuration did not have a detectable effect on gene analysis in samples from subjects with peri-implantitis. CONCLUSIONS: Markers for the plasminogen system and inflammation could be used to distinguish between mucositis and peri-implantitis. The results suggested that the plasminogen system was sufficiently upregulated allowing for resolution of inflammation and healing at the inflamed implant site in subjects with mucositis, whereas such upregulation was insufficient resulting in impaired healing and prolonged inflammation in subjects with peri-implantitis. The combination of tissue inflammation and low levels of tPA was a strong predictor of marginal bone loss in this study. It may be an interesting candidate for the unambiguous diagnosis of mucositis and peri-implantitis independent of radiographs and could possibly constitute a powerful future tool for rapid assessment of the periimplant tissue condition and the effect of subject treatment.

Rehabilitation of edentulous mandibles by means of osseointegrated implants: a 5-year follow-up study on one or two-stage surgery, number of implants, implant surfaces, and age at surgery.

BACKGROUND: In three former reports, the present team has presented the 1-year outcome of four different treatment procedures handling the edentulous mandible; that is, two-stage and one-stage surgery with turned Brånemark System® (Nobel Biocare AB, Gothenburg, Sweden) implants (Group 1 and 2) and one-stage surgery using either 5 or 4 TiUnite™ (Nobel Biocare AB, Gothenburg, Sweden) implants (Group 3 and 4). PURPOSE: The aim of the present investigation was to follow up these patients for a period of 5 years with regard to implant/prosthesis cumulative survival rates, marginal bone loss calculations, clinical complications, and results related to age at surgery. MATERIALS AND METHODS: A total of 385 patients, provided with 1,838 implants, were originally included in the four patient groups. All patients received fixed prostheses. The overall majority of patients had each five implants placed. Radiographs were obtained at prosthesis delivery, at the 1 and 5-year follow-up. RESULTS: A total of 1,230 implants in 259 patients (67%) were possible to follow up for 5 years. Implant Cumulative Survival Rates (CSR) in 5 years for Groups 1-4 were 99.7, 97.0, 98.5, and 98.6%. The corresponding prosthesis treatment CSR was 100, 99.3, 98.5, and 98.6%, respectively. Significantly, more patients (p< .05) lost turned implants after one-stage surgery (Group 2). Frequency distributions of implants revealed that >1.2 mm bone loss was observed around 75 implants (6.4%). The moderately rough central (midline) implant showed more bone loss than other placed implants (Group 3; p< .05). The youngest half of included patients at surgery (Youngest(50%) ; n=193) presented significantly higher mortality than older patients as well as compared to normal population (p< .05). Patients in the Younger(50%) group showed also an association to patients with complete loss of all implants and patients with most implants with obvious bone loss after 5 years. CONCLUSIONS: All four treatment procedures served well during the 5 years of follow-up and only eight patients (2.1%) were complete failures or showed obvious bone loss (>1.8 mm) at several implants (>2 implants), mostly observed in younger patients. The few complications in relation to implant failure and/or obvious bone loss could be associated to both local impact factors (surface, implant site, surgical protocol) as well as to host response factors (systemic health).

Accuracy of virtually planned and conventionally placed implants in edentulous cadaver maxillae and mandibles: a preliminary report.

STATEMENT OF PROBLEM: The accuracy of mental navigation is thought to depend on the clinician's spatial ability. Mental navigation, therefore, is associated with deviations between the mental plan and the definitive implant position. To learn more about the deviation that might occur, it is important to evaluate the accuracy of mental navigation during placement of implants. PURPOSE: The purpose of the study was to compare accuracy outcomes between virtually planned and conventionally placed implants, and among surgeons with varying experience. MATERIAL AND METHODS: Five completely edentulous sets of maxillae and mandibles from human cadaver heads were scanned by computed tomography. Five surgeons planned and placed 60 implants into these jaws, and accuracy was analyzed for 4 parameters: coronal and apical positions, angulation, and depth. The preoperative and postoperative computed tomographies were aligned in voxel-based registration software, which allowed comparison between virtually planned implant positions and actual implant positions. Data were analyzed with the t test (α=.05), ANOVA, and the Scheffé test. RESULTS: Mean (standard deviation) values were as follows: apex, 2.33 ±1.20 mm (range, 0.51-6.31 mm); coronal, 1.88 ±1.02 mm (range, 0.2-5.0 mm); angle, 7.34 ±3.62 degrees (range, 0.19-16.57 degrees); and depth, 0.03 ±1.15 mm (range, -3.47 to 2.10 mm). The apex and coronal position and the angle differed significantly between the virtually planned and actually placed implants. Significant between-surgeon differences were found in implant depth and coronal position. The apex and coronal positions differed significantly between the upper and lower jaw, with better performance achieved in the upper jaw. CONCLUSIONS: The results found statistically significant differences between the virtually planned and conventionally placed implants and among the 5 surgeons.

A two-center retrospective analysis of long-term clinical and radiologic data of TiUnite and turned implants placed in the same mouth.

PURPOSE: The gradual shift from using implants with turned surfaces to implants with moderately rough surfaces has raised questions regarding the long-term behavior of the latter. The aim of the present retrospective study was to compare clinical and radiographic data of the two implant surfaces using the "same mouth" approach. MATERIALS AND METHODS: A total of 122 consecutive patients were treated with both turned and TiUnite implants; however, 26 of these patients could not be reached for follow-up and were excluded from the study. The remaining 96 patients received 257 turned and 243 TiUnite Brånemark System implants, not necessarily supporting the same constructions and not necessarily inserted during the same session. Data were collected up to 10 years of function. RESULTS: During the first 6-year period, 18 turned implants and 1 TiUnite implant failed, resulting in implant cumulative survival rates (CSRs) of 93.0% and 99.1% for turned and TiUnite implants, respectively. During the following years, 1 turned and 3 TiUnite implants failed, resulting in CSRs of 90.3% and 96.6% for the two surfaces, respectively, a significant difference. A small but significant difference in mean bone level was seen between turned and TiUnite implants. CONCLUSION: Implants with turned and TiUnite surfaces showed comparable clinical and radiographic data during the study period. The early implant failure rate, as well as the overall failure rate, were significantly reduced when using TiUnite implants.

Brånemark system implants and rare disorders: a report of six cases.

Rare disorders are conditions defined as either fatal or causing chronic functional impairment. There is limited evidence of the behavior of oral implants in patients suffering from such diseases, and the existing data are merely based on cases reports. This paper describes the outcome of implant treatment after up to 15 years of function in three patients afflicted with X-linked hypophosphatemia, two patients with Langerhans cell histiocytosis, and one patient with osteogenesis/dentinogenesis imperfecta.

Introducing a novel analysis technique for osseointegrated dental implants retrieved 29 years postsurgery.

PURPOSE: To investigate osseointegration of oral implants, which were retrieved from a patient after 29 years in situ, we use novel three-dimensional analysis methods and visualization techniques that supplement conventional two-dimensional analysis. MATERIALS AND METHODS: The sample processing involved nondecalcification and embedment in resin. Conventional two-dimensional histomorphometrical methods were conducted. Additionally, the quantification was extended to three-dimensional by using synchrotron radiation micro-computed tomography (SRµCT) technique and two relevant visualization methods for the three-dimensional data were introduced. RESULTS: The three-dimensional results involved three-dimensional quantification and visualization of two implant samples with methods beyond state-of-the-art. Traditional two-dimensional histomorphometrical results revealed a mean bone-implant contact (BIC) of about 50%. In most samples, bone area (BA) was lower inside the treads compared with out-folded mirror images, which were confirmed by the three-dimensional quantification. The BIC along four selected regions showed highest percentages in the bottom/valley region and lowest in the thread-peak region. Qualitative observations revealed ongoing bone remodeling areas in all samples. The apical hole demonstrated high osseointegration. CONCLUSION: The novel techniques including an animation and an out-folding of BIC and BA enabled a simultaneous visualization of the three-dimensional material obtained from SRµCT data. However, the two-dimensional histological sections were needed for qualitative and quantitative evaluation of osseointegration and, thus, both methods are considered equally important.

Soft tissue augmentation in connection to dental implant treatment using a synthetic, porous material--a case series with a 6-month follow-up.

BACKGROUND: Bony defects/concavities in the aesthetic zone of maxillae may interfere with the results of prosthetic procedures by producing shading superior to the crown. Such regions can be augmented either by bone or soft tissue autografts, allografts, or xenografts. Tissue shrinkage is thus anticipated, and a method to objectively measure the tissue change is valuable. PURPOSE: The aim of this study was to evaluate the use of a synthetic, porous material made of polyurethaneurea for buccal soft tissue augmentation in connection with implant placement in the maxillary front region. Further, to measure over time the change in buccal contour using a computerized technique. MATERIALS AND METHODS: Ten patients received 12 Artelon® cylinders (5 × 10 mm) in connection to implant placement. Preoperative and postoperative (at 3 and 6 months) study casts were obtained for computer measurements, using the preoperative reference model as a base. The volume created between the surfaces of the reference model and each of the two following superimposed models was measured in cubic millimeter. Differences in volume from pretreatment to 3 and 6 months, respectively, were compared. RESULTS: The clinical observation during follow-up showed normal healing. The increase in mean buccal tissue volume was 50 mm(3) (SD 18) after 3 months and 43 mm(3) (SD 21) after 6 months, measured over a 6 mm × 8 mm area in the maxillary front region, in comparison to before insertion of the cylinder. The reduction from 3 to 6 months was not statistically significant (p = .17). CONCLUSION: A synthetic, porous material for soft tissue augmentation was tested in connection to implant placement in the aesthetic zone of maxillae. The buccal contour was followed-up for 6 months using a computer volumetric technique on preoperative and postoperative study casts. Measured tissue volume showed an obvious increase during the study period. The material was biologically well received.

Implant treatment with fixed prostheses in the edentulous maxilla. Part 1: implants and biologic response in two patient cohorts restored between 1986 and 1987 and 15 years later.

PURPOSE: Implant treatment has been performed for more than 45 years, but there is still limited knowledge on how treatment outcomes are changing over time. The aim of this study was to report and compare the treatment outcomes of two patient cohorts from the same clinic, rehabilitated with fixed implant prostheses in the edentulous maxilla between 1986 and 1987 (early) and 2001 to 2004 (late). MATERIALS AND METHODS: The early group included 76 edentulous patients who were consecutively provided with 450 turned Branemark System implants; the late group included 109 edentulous patients provided with 360 turned and 310 TiUnite Branemark System implants. Both groups were followed and evaluated clinically and radiographically for 5 years according to similar protocols. RESULTS: Altogether, 37 patients (20%) were lost to follow-up over 5 years; more patients were noncompliant in the late group (P < .05). The 5-year overall implant cumulative survival rates were 93.4% and 97.3% for the early and late groups, respectively. In the early group, significantly more turned implants failed before prosthesis insertion compared to the outcome of TiUnite implants in the late group (P < .05). Mean bone loss was comparable for the early and late groups during the 5 years of follow-up (0.5 ± 0.46 and 0.7 ± 0.76 mm, respectively), but more patients presented at least 1 implant with more than 2 mm of bone loss during the follow-up period in the late group (P < .05). Mucosal hyperplasia and inflammation showed a trend of higher frequency at implants in the early group of patients (P > .05). CONCLUSION: Implant treatment was more predictable before loading in the late group of patients, related to the change in the implant surface (P < .05). On the other hand, it was observed that the prevalence of patients with more bone loss at at least 1 implant (> 2 mm) was higher in the late group (P < .05). This could possibly be attributed to a more bioactive implant surface and shorter healing period before implant surgery in the late group. Int J Prosthodont 2011;24:345-355.

A controlled clinical exploratory study on genetic markers for peri-implantitis.

PURPOSE: The objective of this controlled exploratory cross-sectional study was to investigate and compare the presence of gene expression of bone resorption/remodelling in peri-implant crevicular fluid samples from healthy subjects and subjects showing obvious clinical and radiographic signs of peri-implantitis. MATERIALS AND METHODS: Peri-implant crevicular fluid (PICF) was sampled from seven healthy subjects and seven subjects with obvious clinical signs of peri-implantitis using paper points. The samples were analysed by quantitative polymerase chain reaction (qPCR). Biomarkers associated with bone degradation/remodelling, such as tartrate-resistant acid phosphatase (TRAP), dickkopf-related protein- 1 (DKK-1), osteoprotegerin (OPG), cathepsin K (CatK) and osteocalcin (OC), were of particular interest in the study. RESULTS: The measured levels of genetic markers were similar for the subjects in the healthy and the peri-implantitis group. Only one subject out of seven with strong and clear clinical signs of peri-implantitis exhibited a panel of genetic markers for ongoing bone degradation. This subject was also diagnosed with rheumatoid arthritis. CONCLUSION: The present data showed that patients with obvious clinical signs of peri-implantitis and a history of bone loss can exhibit similar gene expressions of bone loss/remodelling as clinically healthy implant patients. Absence of bone resorption markers demonstrated that it was not possible to establish ongoing bone degradation in six of seven subjects in the peri-implantitis group. The results suggest that bone resorption was not in progress at the time of PICF sampling, or that cells expressing such markers were not present in significant numbers at the site of PICF sampling.

Rehabilitation of edentulous mandibles by means of four TiUnite implants after one-stage surgery: a 1-year retrospective study of 75 patients.

BACKGROUND: Recently, the present team reported the 1-year data of a one-stage surgery and mainly early loading with five supporting implants in completely edentulous mandibles, indicating more bone loss at the central implant, placed in the midline of the jaw. PURPOSE: The aim of the present retrospective investigation was to evaluate the 1-year results of the same treatment technique with four instead of five supporting implants in completely edentulous mandibles. The outcome was compared with that of a former study (control) on five implants per patient during first year of function. MATERIALS AND METHODS: The present study comprised 75 patients with a total of 300 TiUnite implants (Nobel Biocare AB, Göteborg, Sweden) of mainly the Brånemark System >or= Mark III design. The prosthetic procedure started and was completed on an average of 9.1 days (standard deviation [SD] 4.47) and 33.2 days (SD 16.09) after the surgical intervention, respectively. Intraoral radiographs were obtained at prosthesis insertion and at the 1-year follow-up visit. Failure rates of test and control groups were compared by means of the chi-squared test. RESULTS: All four implants in one patient were found to be mobile at the first annual check-up, resulting in an implant cumulative survival rate (CSR) of 98.5%. The corresponding CSR for the control group was 100% (p > 0.05). The mean marginal bone resorption during the first year of function was 0.3 mm (SD 0.74) as compared with 0.5 (SD 0.56) mm for the control group (p > 0.05). CONCLUSIONS: The outcome of 300 TiUnite implants placed in 75 patients with edentulous mandibles, of which 268 implants in 67 patients were followed for 1 year, showed an implant CSR of 98.5%. The implant survival was not significantly different from that of the control study result of 100%, in which five instead of four supporting implants were used. The levels of marginal bone were close to identical for the corresponding test and control implants at the 1-year check-up.

Clinical experience of TiUnite implants: a 5-year cross-sectional, retrospective follow-up study.

BACKGROUND: Little is known of the long-term clinical and radiographic performance of moderately rough surface implants. PURPOSE: The aim of the present retrospective investigation was to study two pioneer cohorts of patients, that is, the first patients to receive Brånemark System implants with a moderately rough surface (TiUnite, Nobel Biocare AB, Göteborg, Sweden) at the present clinic. TiUnite implants were inserted either in compromised bone sites in a mixed-mouth concept together with turned implants or used solely. Patients were followed up over a period of 5 years with regard to implant survival and the marginal bone response. MATERIALS AND METHODS: Patients who received both implant types (mixed group) comprised 41 subjects, and the second group (TiUnite group) comprised 70 subjects. A total of 110 turned and 68 TiUnite implants were placed in the mixed group, and 212 TiUnite implants in the TiUnite group. Follow-up radiographs were obtained at prosthesis placement and at the 1- and 5-year check-ups, and examined by independent observers. RESULTS: One turned (0.9%) and two TiUnite (2.9%) implants failed in the mixed group, and three implants (1.6%) failed in the TiUnite group, indicating no significant differences between surfaces or groups (p < .05). The mean marginal bone loss at 5 years was 0.6 mm to 0.8 mm, also indicating no significant differences for the two implant types tested in the mixed group. CONCLUSIONS: Cumulative survival rates for the two implant surfaces were favorable at 5 years, and the marginal bone loss was low and similar for both implant surfaces.

Marginal bone loss at implants: a retrospective, long-term follow-up of turned Brånemark System implants.

BACKGROUND: Lately, presence of progressive bone loss around oral implants has been discussed. PURPOSE: The aim of this study was to report in a large patient group with different prosthetic restorations marginal bone level and its change as measured in radiographs obtained from prosthesis insertion up to a maximum 20 years in service. Further, it also aimed to study the impact of gender, age, jaw, prosthetic restoration, and calendar year of surgery. MATERIALS AND METHODS: Out of 1,716 patients recorded for clinical examination during 1999, 1,346 patients (78.4%) could be identified. A total of 640 patients (3,462 originally installed Brånemark System implants, Nobel Biocare, Göteborg, Sweden) with a follow-up of >or=5 years were included in the study, while patients with continuous overdentures and augmentation procedures were not. Distance between the fixture/abutment junction (FAJ) and the marginal bone level was recorded. RESULTS: The number of implants with a mean bone level of >or=3 mm below FAJ increased from 2.8% at prosthesis insertion to 5.6% at year 1, and 10.8% after 5 years. Corresponding values after 10, 15, and 20 years were 15.2, 17.2, and 23.5%, respectively. 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 follow-up time, altogether 183 implants (107 patients) showed a bone loss >or=3 mm from prosthesis insertion to last examination. Significantly larger bone loss was found the older the patient was at surgery and for lower jaw implants. CONCLUSIONS: Marginal bone support at Brånemark implants was with few exceptions stable over years.

Digitally planned, immediately loaded dental implants with prefabricated prostheses in the reconstruction of edentulous maxillae: a 1-year prospective, multicenter study.

BACKGROUND: The introduction of digital planning programs has made it possible to place dental implants in preplanned positions and being immediately functionally loaded by using prefabricated prostheses. PURPOSE: The aim of this multicenter study was to describe the 1-year results of digitally planned, immediately loaded edentulous maxillae. MATERIALS AND METHODS: A total of 312 implants (Brånemark System, TiUnite RP, Nobel Biocare, Göteborg, Sweden) in 52 patients from eight Scandinavian clinics were digitally planned, surgically as well as prosthetically, by using the NobelGuide (Nobel Biocare AB, Göteborg, Sweden) and received prefabricated, immediately loaded fixed prosthetic constructions in the maxillae. Individual implant stability was manually tested at 1-year follow-up. RESULTS: All patients received a Procera Implant Bridge (Nobel Biocare AB); however, in two cases, the bridges were reconstructed due to misfit. In five patients, difficulties in getting the surgical guide completely in position, and in five patients, getting the prostheses completely seated, were noted. All but four patients fulfilled the 1-year follow-up. Two implants were lost during the study period, resulting in a cumulative survival rate of 99.4%. The mean marginal bone resorption from implant placement to the 1-year follow-up was 1.3 mm (SD 1.28). More than 2 mm of marginal resorption was noted in 19% of the implants at this instant. The most frequently reported complications during the first year were gingival hyperplasia and prosthesis-related problems (prosthesis screw loosening, occlusal fractures, and occlusal adjustments). CONCLUSION: The 1-year results in this multicenter are promising regarding implant and bridge stability; however, the study is planned to be running for at least 3 years.