Inflammatory Gene Profile and Particle Presence in Peri-Implant Mucosa: a Pilot Study on 9 Patients.

Objectives: The purpose of this pilot study is to compare gene expression in mucosa around dental implants with zirconia abutment to titanium and investigate presence of particles in mucosa samples and on implant heads. Material and Methods: Ten patients with a single implant supported prosthesis connected to zirconia or titanium abutments were invited at the five-year control. A clinical examination and a survey on experience of function and appearance were conducted. A mucosa biopsy taken in close vicinity to the implant were analysed by real-time polymerase chain reaction (qPCR) and presence of particles in a scanning electron microscope/energy-dispersive X-ray spectroscope (SEM/EDX). Cytological smear samples were collected and analysed through inductively coupled plasma mass spectrometry (ICP-MS) to investigate presence of particles on implant heads. Results: In total, 9 patients participated in the study, five with titanium abutments and four with zirconia abutments. All patients were satisfied with function and aesthetics. Titanium and iron particles were detected in mucosa biopsies. The ICP - MS analysis demonstrated presence of zirconia and titanium. Several proinflammatory genes were upregulated in the zirconia abutment group. Conclusions: Around zirconia abutments a slight increase in proinflammatory response and amount of wear particles was seen as compared to titanium. Wear particles of titanium were present in all soft tissue samples, however zirconia particles only in the samples from implants heads/mucosa with zirconia abutments.

Long-term performance of implants with moderately rough anodized surface supporting single-tooth restorations: A retrospective analysis with an up to 15-year follow-up.

OBJECTIVES: This retrospective study aimed to evaluate long-term clinical and radiologic performance of anodized surface implants supporting single implant restorations. MATERIALS AND METHODS: Patients who received at least one anodized surface implant for a single-tooth restoration between 2003 and 2004 in the Brånemark clinic (Göteborg, Sweden) were included in the study. The assessed outcomes included implant survival, biological and technical complications, as well as marginal bone levels (MBL) based on radiographs. Baseline data on patient demographics, implant placement, and surgery details were also collected. The cumulative survival rate (CSR) was calculated using the Kaplan-Meier survival analysis. RESULTS: The study included 97 patients with 129 implants. Mean patient age at the time of implant placement was 31.7 ± 16.4 years. All implants were placed in a two-stage approach with delayed loading. The last follow-up visit was on average 13.4 ± 4.8 years after implant insertion. Three implants failed, yielding the implant-level 15-year CSR of 97.4%. Majority of the implants had no biological (70.5%) nor technical (81.4%) complications. The mean MBL was -1.0 ± 0.7 mm (n = 101) at prosthetic placement and -1.8 ± 1.0 mm (n = 80) at the last follow-up, while the mean marginal bone loss (MBL) from prosthetic placement to last follow-up was 0.6 ± 1.1 mm (n = 65). CONCLUSIONS: Moderately rough anodized implants have shown favorable long-term outcomessingle-tooth indication, with high survival and a low rate of technical complications. Furthermore, long-term studies are needed to present longitudinal data on peri-implantitis.

Could Age at Surgery Be Associated with Early Mortality After Implant Surgery? A Retrospective Study of 3,877 Edentulous Patients.

PURPOSE: Knowledge of the early mortality patterns in edentulous implant patients is limited. This study aimed to report patient mortality within the first year after surgery and compare the cause of death with preexisting conditions reported before surgery. MATERIALS AND METHODS: In this retrospective cohort study, data from the Swedish National Death Register on patients, consecutively treated in the edentulous arch between 1986 and 2013, were compared with information from the patient files regarding the preexisting health conditions of the deceased patients. One-year survival rates were calculated and compared with expected mortality in a Swedish reference population based on three age groups: young (< 45 years of age), middle-aged (45 to 64 years of age), and old patients (> 64 years of age). Proportions of mortality between study groups and reference populations were tested by means of a log-rank test, and agreement between diagnoses before surgery and cause of death was tested by means of kappa test. RESULTS: Altogether, 3,877 patients were included, of whom 60 patients died within 1 year after implant surgery (1.5%). The expected mortality in the Swedish reference population was 2.1% (P < .05). Mortality was higher for middle-aged (P = .02) but lower for old patients (P = .0001) compared with the Swedish reference populations. Eight of the deceased patients (13%) had no preexisting conditions, while 48 patients reported a health diagnosis before implant surgery. The most common of these were related to the circulatory system (ICD 10-I), which was the cause of death for 30 patients. A "none to slight agreement" between presurgical diagnoses and cause of death was observed in the population (kappa: 0.152). CONCLUSION: Edentulous implant patients presented overall lower mortality than expected in the general population during the first year after surgery. However, middle-aged patients showed a higher proportion of deceased patients compared with control people of the same age. Cardiovascular diseases were the cause of death in 50% of the group, and the agreement between presurgical and cause of death diagnoses was poor.

Patient factors related to early implant failures in the edentulous jaw: A large retrospective case-control study.

BACKGROUND: Dental implants provide anchorage for dental prostheses to restore functions for individuals with edentulous jaws. During the healing phase, proper osseointegration is required to prevent early implant failure. More knowledge is needed regarding factors related to early failure of dental implants. PURPOSE: The aim of the present study was to identify possible risk factors for early implant failure, with respect to anamnestic and clinical parameters. MATERIALS AND METHODS: All patients with edentulous jaws with early implant failure (n = 408) from one referral clinic were compared with a matched control group (n = 408) with no implant failure. Early implant failure was identified during the first year of prosthetic function. Matching was performed on age, gender, year of surgery, type of jaw, and type of implant surface. In addition, data on anamnestic and clinical parameters were collected. The data were analyzed with a multivariable logistic regression model using early implant failure as the binary outcome. RESULTS: Five anamnestic factors were statistically significant with respect to higher probability for early implant failure: systemic disease, allergies in general, food allergies, smoking, and intake of analgesic medication. Four clinical conditions (i.e., implants in the opposing jaw, low primary stability, reduced bone volume, and healing complications) were also related to higher probability for early implant failure. CONCLUSIONS: This study identified nine factors associated with early implant failure, several related to patient's general health. Further investigations are needed to fully understand the causality between the obtained variables and early implant failure.

Causes of Death in Implant Patients Treated in the Edentulous Jaw: A Comparison between 2098 Deceased Patients and the Swedish National Cause of Death Register.

BACKGROUND: Previous research has reported an association between tooth loss and patient mortality, while the cause of death has not been elucidated. OBJECTIVE: The purpose was to describe and compare the cause of death in implant patients treated consecutively in the edentulous arch with a reference population. METHODS: Altogether, 3902 patients were included between 1986 and 2014. Data on the causes of death for deceased patients were compared to the Swedish National Cause of Death Register for a comparable time period. Standardised mortality ratios (SMRs) were calculated based on gender and age and tested for statistical significance. RESULTS: Most deceased patients (2,098) died from diseases in the circulatory system (CVD; 42%) and from cancers (26%). SMR indicated a generally increased mortality (total group) compared to the reference population during inclusion (P < 0.05; 1986-2014). Patients treated early (1986-1996) showed a lower SMR compared to patients treated later (P < 0.05; 1997-2014) especially related to CVDs. Younger patients (<60 years at surgery) showed an increased mortality due to CVDs when treated late (1997-2014; SMR = 5.4, P < 0.05). Elderly patients (>79 years at surgery) showed a significantly lower mortality in almost all observed causes of death (1986-2014; P < 0.05) with also a significantly lower mortality due to CVDs during the early period (1986-1996; SMR = 0.3, P < 0.05). CONCLUSION: An overall increased mortality was observed for the edentulous implant patient compared to the reference population. Elderly patients (>79 years) showed significantly lower mortality for all causes of death independent of the time period of implant surgery. Younger patients (<60 years) present an increased risk for early mortality related to CVD. SMR for all causes of death increased for patients treated late (1997-2014) as compared to patients treated early (1986-1996).

Early Implant Failures in Edentulous Patients: A Multivariable Regression Analysis of 4615 Consecutively Treated Jaws. A Retrospective Study.

PURPOSE: To study the incidence of early implant failures in edentulous jaws and to describe the effects of some patient- and implant-related factors on the risk for early implant failures. MATERIALS AND METHODS: The study retrospectively analyzed 4615 edentulous jaws (4067 patients), consecutively treated with dental implants at one referral clinic from 1986 to 2013. Implant failures that occurred from implant surgery up to the first recall examination 1 year after prosthesis insertion were recorded and defined as early implant failures. All removed implants were included as failures. Features of the study group and early implant failure rates were reported. A multivariable logistic regression model was used for analyzing possible associations between clinical factors, and the risk for early implant failures. Implant surfaces were categorized by means of roughness: turned (Sa 0.5-1.0 µm) and moderately rough (Sa 1.0-2.0 µm). RESULTS: Three hundred twenty-seven patients (344 jaws) were lost to follow-up. Early implant failures occurred in 8.6% of the jaws. In the maxilla there was a significantly higher incidence of early failures compared to the mandible both with turned implants, OR 5.93 (95% CI 4.21; 8.36), and moderately rough implants, OR 2.52 (95% CI 1.19; 5.34). The impact of implant surface roughness was significant in the maxilla with higher incidence of early failures with turned implants, OR 3.51 (95% CI 2.27; 5.42). There was a significant interaction between implant surface and jaw type on early failures (p = 0.034). Older age was associated with lower risk for early implant failures, OR 0.9 (95%CI 0.82; 0.99). In total, 63% of the jaws with failure could proceed with the prosthetic treatment without further implant insertions. Twenty-six percent of the early failures occurred after prosthesis insertion and 59% of those could maintain the same prosthesis after implant loss with or without adjustments. CONCLUSIONS: Changing the implant surface from turned to moderately rough decreased the incidence of early implant failures significantly in the maxilla, but not in the mandible. Older age at implant insertion was associated with lower risk for early implant failures in edentulous patients.

Inflammatory cytokine release from human peripheral blood mononuclear cells exposed to polyetheretherketone and titanium-6 aluminum-4 vanadium in vitro.

Objective To investigate the cytokine expression profiles of blood cells exposed to polyetheretherketone and titanium-6 aluminum-4 vanadium materials in vitro. Materials and methods Coin-shaped samples composed of titanium-6 aluminum-4 vanadium, polyetheretherketone, and blasted polyetheretherketone were manufactured. The surfaces of the coins were characterized using optical interferometry, scanning electron microscopy, and contact angle measurements. Peripheral blood mononuclear cells collected from 10 blood donors were cultured for one, three, and six days in the presence or absence of the coins, and then assayed for cytokine production. Quantification of the peripheral blood mononuclear cells attached to the coins was performed using confocal microscopy after immunofluorescence staining. Results The machined titanium-6 aluminum-4 vanadium coins had a smoother surface topography compared to the machined polyetheretherketone and blasted polyetheretherketone. The highest mean contact angle was noted for the blasted polyetheretherketone, followed by the machined polyetheretherketone and titanium-6 aluminum-4 vanadium. The peripheral blood mononuclear cells produced significantly more proinflammatory cytokines when exposed to the polyetheretherketone surface compared to the titanium-6 aluminum-4 vanadium surface, while the blasted polyetheretherketone induced the highest level of proinflammatory cytokine release from the peripheral blood mononuclear cells. Significantly more cells attached to both polyetheretherketone surfaces, as compared to the titanium-6 aluminum-4 vanadium surface. Conclusion Polyetheretherketone induces a stronger inflammatory response from peripheral blood mononuclear cells than does titanium-6 aluminum-4 vanadium. Surface topography has an impact on cytokine release from peripheral blood mononuclear cells.

Associations Between Early Implant Failure, Patient Age, and Patient Mortality: A 15-Year Follow-Up Study on 2,566 Patients Treated with Implant-Supported Prostheses in the Edentulous Jaw.

PURPOSE: The aim of this study was to report the distribution of patients with early implant failures after implant treatment in the edentulous jaw with regard to age at surgery and association with patient mortality over a 15-year period. MATERIALS AND METHODS: All consecutively treated patients treated in the edentulous jaw at a single specialist clinic from 1986 to 1997 were included and followed up for 1 year for implant failures and for 15 years with regard to patient mortality. Patients were arranged into age groups, and life tables for patients and reference groups of patients with comparable age (based on national population data) were calculated. Log rank test was used to test differences in patient survival between those with reported early implant failures and those with no early failures. Mantel-Haenszel chi-square test was used to test association between proportions of implant failures and age groups. RESULTS: A total of 55 patients were excluded because they were not living in Sweden (nonresidents/emigrated). Altogether, 2,566 patients were included, with a mean age of 65 years (SD: 11). Of these, 988 patients were deceased during the 15 years of follow-up (38%), and 291 presented an early implant failure (11.3%), most of them before prosthesis placement (72%). Patients with early implant failures presented higher mortality rates than patients with no failures (P < .05), and failure rates decreased consistently from younger to higher age groups (P < .05). CONCLUSION: Patients in the younger age groups showed an increased mortality compared with the reference group (P < .05) and a higher prevalence of early failures compared with older patients (P < .05). Older patients showed an opposing pattern of lower mortality compared with reference groups of comparable age (P < .05), but both younger and older patients with early failures showed a higher mortality compared to patients with no failures (P < .05).

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.

Patterns of Mortality in Patients Treated with Dental Implants: A Comparison of Patient Age Groups and Corresponding Reference Populations.

PURPOSE: Little is known about the relationship between implant patient mortality compared to reference populations. The aim of this study was to report the mortality pattern in patients treated with dental implants up to a 15-year period, and to compare this to mortality in reference populations with regard to age at surgery, sex, and degree of tooth loss. MATERIALS AND METHODS: Patient cumulative survival rate (CSR) was calculated for a total of 4,231 treated implant patients from a single clinic. Information was based on surgical registers in the clinic and the National Population Register in Sweden. Patients were arranged into age groups of 10 years, and CSR was compared to that of the reference population of comparable age and reported in relation to age at surgery, sex, and type of jaw/dentition. RESULTS: A similar, consistent, general relationship between CSR of different age groups of implant patients and reference populations could be observed for all parameters studied. Completely edentulous patients presented higher mortality than partially edentulous patients (P < .05). Furthermore, implant patients in younger age groups showed mortality similar to or higher than reference populations, while older patient age groups showed increasingly lower mortality than comparable reference populations for edentulous and partially edentulous patients (P < .05). CONCLUSION: A consistent pattern of mortality in different age groups of patients compared to reference populations was observed, indicating higher patient mortality in younger age groups and lower in older groups. The reported pattern is not assumed to be related to implant treatment per se, but is assumed to reflect the variation in general health of a selected subgroup of treated implant patients compared to the reference population in different age groups.

Incidence of First Implant Failure: A Retroprospective Study of 27 Years of Implant Operations at One Specialist Clinic.

BACKGROUND: Even though there are many studies available reporting on implant failures, there are few studies that follow implant failures over time in large populations. PURPOSE: The purpose of this article is to present an overview of the annual incidence of reported implant failures for patients and operations over a 28-year period. MATERIALS AND METHODS: A total of 8,528 patients were consecutively provided with 39,077 implants in 10,719 implant operations during a 27-year period (1986-2012) at one specialist clinic. All patients with reported failures of implants during a 28-year routine follow-up period (1986-2013) were included, and data from the patients' files were retrieved and reported. RESULTS: Altogether, 857 patients (882 jaws/operations) were identified with one or more failures (10.0% of patients/8.5% of operations). Mean annual incidence of first failure showed obvious variations between years, even between seemingly clinically similar situations. However, incidence of first implant failure was higher for upper than lower jaws (p < .05), within 1 year of surgery (69%) than after 1 year (p < .05), and for implants with a turned surface compared with implants with a moderately rough surface (p < .05). CONCLUSIONS: With regard to annual failure incidence in relation to total number of operations over time, obvious variations in failure rate can be observed between seemingly similar clinical situations, as well as significant differences in incidence of first implant failure between the first year after surgery and later time points, between upper and lower jaws using implants with turned surfaces, and between operations to install implants with turned surfaces and those to install implants with moderately rough surfaces.

Mortality patterns in partially edentulous and edentulous elderly patients treated with dental implants.

UNLABELLED: An association between oral health, number of teeth, and mortality has been reported in the literature, but limited knowledge is available on mortality in elderly partially edentulous and edentulous patients treated with implants. PURPOSE: The aim of this retrospective study was to compare the mortality pattern in elderly patients (80 years or older) who were provided with implants and were partially or completely edentulous. MATERIALS AND METHODS: Between 1986 and 2003, a total of 266 elderly patients with a mean age of 83.0 years at the time of implant placement were included. The patients were provided with 1,384 Brånemark System implants (Nobel Biocare) in 285 arches. The sample was divided into two subgroups: 108 edentulous patients and 158 partially edentulous patients. Information was collected for each individual regarding expected remaining lifetime at the time of implant surgery. Cumulative survival rate (CSR) was calculated and compared for the two subgroups covering 10 years and was also compared to expected CSR data for normal populations of comparable distribution. RESULTS: Mortality was significantly decreased (P < .05) for partially edentulous compared with edentulous patients (-10.4%) after 10 years of follow-up. CSR for the elderly groups showed a significant decrease in mortality compared with comparable groups of normal populations (P < .05). There was no significant difference in morality between healthy/nonhealthy patients at first surgery or patients with reported/unreported implant failures (P > .05). CONCLUSIONS: Elderly partially edentulous patients had significantly lower mortality compared with edentulous patients over a 10-year period of follow-up. Both subgroups also showed significantly lower mortality compared with normal populations of comparable sex and age at the time of implant surgery. The observation is interpreted as that these patients are healthier and more motivated to replace their lost teeth with implants than the normal population rather than that implant treatment per se reduces mortality.

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.

Onlay and inlay bone grafts with platelet-rich plasma: histologic evaluations from human biopsies.

PURPOSE: The aim of the present study was to histomorphometrically evaluate biopsies from 1) sinus inlay bone grafts prepared with or without platelet-rich plasma (PRP) and 2) onlay bone grafts in the anterior maxilla with particulate bone and PRP or block bone without PRP after 3 months. MATERIALS AND METHODS: Biopsies were retrieved with a trephine drill, and samples were processed in laboratories to result in nondecalcified cut and ground sections. Light microscopic measurements of total bone area, new bone, number of vessels, and vessel area were performed at 3 regions in each sample. Calculations of ratios of new bone to total bone and vessel area to total area were performed. RESULTS: There was a tendency toward higher mean values for total bone area percentage and area of newly formed bone in the PRP-treated inlay biopsies. However, there was no measurable effect on vessel formation in the PRP-treated inlay samples compared with untreated inlay samples. Particulate and PRP-treated onlay bone biopsies showed higher mean values in all measured parameters compared with block bone samples; however, no differences were statistically significant. CONCLUSION: PRP treatment may favor bone formation in grafted bone, and further research is needed to describe the outcome of PRP treatment and grafting techniques in the maxilla.

Bone reaction to nano hydroxyapatite modified titanium implants placed in a gap-healing model.

Nanohydroxyapatite materials show similar chemistry to the bone apatite and depending on the underlying topography and the method of preparation, the nanohydroxyapatite may simulate the specific arrangement of the crystals in bone. Hydroxyapatite (HA) and other CaP materials have been indicated in cases in which the optimal surgical fit is not achievable during surgery, and the HA surface properties may enhance bone filling of the defect area. In this study, very smooth electropolished titanium implants were used as substrata for nano-HA surface modification and as control. One of each implant (control and nano HA) was placed in the rabbit tibia in a surgical site 0.7 mm wider than the implant diameter, resulting in a gap of 0.35 mm on each implant side. Implant stability was ensured by a fixating plate fastened with two side screws. Topographical evaluation performed with an optical interferometer revealed the absence of microstructures on both implants and higher resolution evaluation with AFM showed similar nanoroughness parameters. Surface pores detected on the AFM measurements had similar diameter, depth, and surface porosity (%). Histological evaluation demonstrated similar bone formation for the nano HA and electropolished implants after 4 weeks of healing. These results do not support that nano-HA chemistry and nanotopography will enhance bone formation when placed in a gap-healing model. The very smooth surface may have prevented optimal activity of the material and future studies may evaluate the synergic effects of the surface chemistry, micro, and nanotopography, establishing the optimal parameters for each of them.

Bone graft and implants in a patient with systemic mastocytosis.

BACKGROUND: Systemic mastocytosis (mast-cell proliferation in various organs, including the skeleton) is a rare disease. Reports on mastocytosis that affects facial bones are few. The bone lesions may be osteolytic or sclerotic. PURPOSE: To describe (for the first time) bone grafting followed by dental implant treatment yielding a good result in a patient with systemic mastocytosis. MATERIALS AND METHODS: A bone graft was performed on a 60-year-old woman with systemic mastocytosis. Dental implant treatment was performed 13 weeks after sclerotic bone of the iliac crest was grafted to the maxillary sinus bilaterally. A microimplant was installed simultaneously with the dental implants and was removed 6 months later for histomorphometric evaluation. Bone biopsy specimens from the donor site of the sclerotic iliac crest and later from the remodeled maxillary bone graft were histologically analyzed. A clinical examination of the patient with regard to her mastocytosis was performed by a dermatologist. The patient was followed up after 3 years. RESULTS: Bone grafting and dental implant treatment were successful, and the patient's clinical and radiologic situation was stable after 3 years. Histologic examination of the bone grafted from the iliac crest showed sclerotic lesions in the bone and a dense infiltration of mast cells. The bone graft seemed to remodel initially in a normal way in the maxillary sinus. However, computed tomography 3 years later showed regions of sclerosis in the remodeled maxillary bone. These lesions now had a pattern similar to the adjacent facial bone. Both the microimplant and the dental implants integrated well. Bone-implant contact measured on the microimplants was 20% higher in this actual case, compared to that of patients previously treated and grafted with the same technique. CONCLUSIONS: There are many clinical implications to be considered when treating this group of patients. Bone grafting, remodeling of the bone, and dental implant installation were successful in this patient with systemic mastocytosis and signs of osteosclerosis. Installation of microimplants in patients with pathologic bone conditions may allow successful dental implant treatment.

FGF-4 and titanium implants: a pilot study in rabbit bone.

AIM: To evaluate the effect of a local single injection of amino-terminally truncated recombinant human fibroblast growth factor-4 (rhFGF-4s) on titanium implant incorporation in a rabbit bone. MATERIAL AND METHODS: Thirty-six threaded titanium implants were inserted into the femur and tibia of six rabbits. Three weeks prior to implant insertion 10 microg of FGF-4 in an altelocollagen carrier or the carrier alone was injected into the intended implant sites. Biomechanical evaluation by (i) resonance frequency analysis and (ii) peak removal torque measurements was performed after 6 weeks. The implants with surrounding tissue were processed to undecalcified ground sections followed by light-microscopic quantifications of the bone in threaded area and the apical parts of the implants. RESULTS: A general trend, however not statistically significant, with higher mean values obtained in the above-mentioned tests was found. The FGF-4-treated implants revealed a significantly increased bone area in the apical part of the implants compared to the corresponding control implants. CONCLUSION: A local single injection of rhFGF-4 may stimulate bone formation around titanium implants in bone. However, further research is required to confirm these results, understand the mechanisms of FGF, and establish optimal dose and delivery methods.

Failure to induce supracrestal bone growth between and around partially inserted titanium implants using bone morphogenetic protein (BMP): an experimental study in dogs.

The effect of bone morphogenetic protein on supracrestal bone growth around partially inserted implants in a dog model is described. The lower premolar teeth (P1, P2, P3 and P4) were extracted on both sides of the mandible in six dogs. At a surgical exposure 12 weeks later, two 10-mm turned titanium implants were partially inserted, approximately 15 mm apart, in the areas of the P1 and P3 in each side of the mandible, allowing five threads to protrude from the bone crest. A titanium mesh was fastened to the coronal aspect of the two fixtures and the space beneath the mesh was filled with bone morphogenetic protein (S300 BMP) in combination with an insoluble bone matrix carrier, or with the carrier alone. The mesh was covered with an ePTFE membrane. Thus, a space for potential bone formation was created between the two implants. The surgical flaps were coronally positioned and secured with vertical mattress sutures. After 16 weeks of healing, biopsy specimens were retrieved and examined histologically. Bone was not formed around the protruding implants or in the created space between the implants in any case. The carrier was incompletely resorbed. We conclude that supracrestal bone growth beyond the crestal limit with or without BMP in such a large space as in this experimental design may not be possible.

Dog model for study of supracrestal bone apposition around partially inserted implants.

A dog model for study of supracrestal bone growth around partially inserted implants is described. The mandibular premolar teeth (P1, P2, P3 and P4) were extracted on both sides of the mandible in four dogs. At a surgical exposure 12 weeks later, two 10 mm titanium implants were partially inserted on each side, 15 mm apart, in the areas of the P1 and the P3 so that five threads protruded from the bone crest. A titanium mesh was fastened to the coronal aspect of the two fixtures and covered with an ePTFE membrane. Thus, a space for potential bone formation was created between the two implants. The surgical flaps were coronally positioned and secured with vertical mattress sutures. After 12 weeks of healing, biopsy specimens were retrieved and examined histologically. In three of the four dogs under study, the partially inserted implants had integrated and the intended large wound spaces had been created around the noninserted parts of the implants. However, bone was not formed around the protruding implants. Accordingly, this experimental model may prove useful for future studies on the use of various procedures that hypothetically may enhance bone formation.

Recent outcomes and perspectives of the application of bone morphogenetic proteins in implant dentistry.

BACKGROUND: Since the discovery of bone morphogenetic proteins (BMPs), the number of related studies has increased substantially, and more recent outcomes have cast encouraging perspectives on their use in reconstructive surgery. PURPOSE: The aim of the present review was to summarize the present knowledge about the use of BMPs in conjunction with dental implants based on the literature. MATERIALS AND METHODS: Scientific articles dealing with the use of growth factors and bone healing with or without dental implants were searched for on MEDLINE and critically scrutinized. RESULTS: Thirty-nine scientific reports formed the base for the present review. Whereas the osteoinductive capability of BMPs is well documented, studies on their effects in implant dentistry are still incipient. Preclinical and clinical studies did not show outstandingly good outcomes of the application of BMPs compared with conventional treatments or controls. CONCLUSIONS: The number of studies in the field of dental implantology in which BMPs have been used is still too small for establishing clinical protocols of their use in order to improve a recipient bone bed prior to implant placement or to enhance the integration process of an implant.