[Show abstract][Hide abstract] ABSTRACT: Clinical studies show promising outcomes with implants inserted at the time of extraction. However, this often results in an initial bone defect at the marginal region which preferably should heal for an optimal function. Therefore, monitoring of these implants is vital.
The aims of this study were to determine the initial stability of implants placed into fresh extraction sockets, and to explore the correlations between the peri-implant bone levels and implant stability parameters.
Six human cadaver mandibles including all natural teeth were selected for this study. All natural teeth were gently extracted, and 84 implants were immediately placed into fresh extraction sockets with five different implant depths. The maximum insertion torque values were recorded, and primary implant stability measurements were performed by means of resonance frequency analysis (RFA). The vertical distance between implant/abutment junction and the first bone-implant contact was recorded using a periodontal probe.
It was found that the insertion torque and RFA were 28.9 +/- 7 Ncm and 65.6 +/- 9 implant stability quotient (ISQ), respectively, for 420 measurements from all 84 implants. Statistically significant correlation was found between insertion torque and ISQ values (r = 0.86; p < .001) for all implants. Both insertion torque and ISQ values dramatically decreased when the amount of peri-implant vertical bone defect increased.
The results of this study demonstrated a linear relationship between peri-implant vertical bone defect depth and RFA value. It is proposed that the RFA method is sensitive to detect changes of the marginal bone level and may be used to monitor healing of peri-implant bone defects.
Full-text · Article · May 2008 · Clinical Implant Dentistry and Related Research
[Show abstract][Hide abstract] ABSTRACT: Recent studies have showed that immediate/early loading of dental implants is a clinically feasible concept with results similar to those for standard two-stage procedures, especially in the mandible. However, there are only a few studies regarding the immediate/early loading of maxillary implants supporting single-tooth crowns.
The aim of this study was to compare the clinical and radiological outcomes of early- and delayed-loaded dental implants supporting single-tooth crowns in the maxilla.
Twenty-nine patients were consecutively treated between 2000 and 2002 with 59 Brånemark System MK III TiUnite implants (Nobel Biocare AB, Göteborg, Sweden) in the maxilla. Two groups were formed according to the loading protocols. In the test group, definitive implant-supported single crowns were delivered to 19 patients 6 weeks after the implant placement. In the control group, definitive implant-supported single crowns were delivered to 10 patients 6 months after the implant placement. Clinical and radiographic parameters were recorded at baseline, 1 to 4 years. Implant stability measurements have only been performed at 4-year follow-up recall.
Overall, three implants were lost during the study period. Two implants were lost in the test group including 36 implants, which indicated a survival rate of 94.4%. One of the lost implants was replaced and then osseointegrated successfully. One implant was lost in the control group during the healing period, which indicated a survival rate of 95.7%. The average marginal bone loss was 1.11 mm for 56 implants after 4 years. There were no significant differences in marginal bone levels, insertion torque, and resonance frequency values between the two groups.
The results of this study indicate that 6 weeks of early loading period for TiUnite-surface titanium implants in the maxilla is reliable and predictable for this patient population and may offer an alternative to the standard loading protocol.
No preview · Article · Jan 2008 · Clinical Implant Dentistry and Related Research
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to determine the relationship between bone density, insertion torque, and implant stability at implant placement.
One-hundred and eight patients were treated with 230 Brånemark System implants. A computerized tomography (CT) machine was used for pre-operative evaluation of the jaw bone for each patient. The maximum insertion torque values were recorded with the OsseoCare equipment. Implant stability measurements were performed with the Osstell machine for only 142 implants.
The mean bone density and insertion torque values were 721+/-254 Hounsfield unit (HU) and 39.1+/-7 N cm for 230 implants, and the correlation was significant (r=0.664, p<0.001). The mean bone density, insertion torque, and resonance frequency analysis values were 751+/-257 HU, 39.4+/-7 Nc m, and 70.5+/-7 implant stability quotient (ISQ), respectively, for 142 implants. Statistically significant correlations were found between bone density and insertion torque values (p<0.001); bone density and ISQ values (p<0.001); and insertion torque and ISQ values (p<0.001).
The bone density values from pre-operative CT examination may provide an objective assessment of bone quality, and significant correlations between bone density and implant stability parameters may help clinicians to predict primary stability before implant insertion.
No preview · Article · Aug 2007 · Journal Of Clinical Periodontology
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to determine the bone density in the designated implant sites using computerized tomography (CT), the fastening torque values of dental implants, and the implant stability values using resonance frequency analysis. Further aim was to evaluate a possible correlation between bone density, fastening torque and implant stability. Eighty-five patients were treated with 158 Brånemark System implants. CT machine was used for preoperative evaluation of the jawbone for each patient, and bone densities were recorded in Hounsfield units (HU). The fastening torque values of all implants were recorded with the OsseoCare equipment. Implant stability measurements were performed with the Osstell machine. The average bone density and fastening torque values were 751.4 +/- 256 HU and 39.7 +/- 7 Ncm for 158 implants. The average primary implant stability was 73.2 +/- 6 ISQ for seventy implants. Strong correlations were observed between the bone density, fastening torque and implant stability values of Brånemark System TiUnite MKIII implants at implant placement (P < 0.001). These results strengthen the hypothesis that it may be possible to predict and quantify initial implant stability and bone quality from pre-surgical CT diagnosis.
No preview · Article · Jan 2007 · Journal of Oral Rehabilitation
[Show abstract][Hide abstract] ABSTRACT: The original Brånemark protocol for dental implant treatment was based on submerged healing prior to loading. In recent years, immediate/early functional loading has been reported to be possible with high success for various indications including two splinted mandibular implants supporting an overdenture. However, there are a limited number of studies regarding the early loading protocol for two unsplinted mandibular implants supporting an overdenture.
A total of 26 edentulous patients were treated with two unsplinted dental implants supporting mandibular overdentures. All implants were placed in the canine regions of each mandible according to the one-stage surgery. For the test group, overdentures were connected 1 week after surgery, and for the control group, overdentures were connected 3 months after surgery. Peri-implant parameters were recorded 1, 6, 12, 18, and 24 months after surgery. Marginal bone levels were evaluated at implant placement and after 6, 12, 18, and 24 months. Clinical stability measurements were performed at surgery, and after 3, 6, 12, 18, and 24 months.
No implant from either group was lost during 2 years. Clinical peri-implant parameters, clinical implant stability measurements, and marginal bone resorptions showed no statistically significant differences between the two groups during 24 months.
The results of this clinical trial suggest that the early loading approach of two dental implants supporting a mandibular overdenture does not jeopardize peri-implant soft tissue health, marginal bone resorption, and implant stability.
No preview · Article · Jan 2007 · Journal of Periodontology