Welcome to Bicon South Africa Professionals' Site

Long term bone level stability on Short Implants: A radiographic follow up study

Caterina Venuleo, Sung-Kiang Chuang, Meghan Weed, Serge Dibart

Abstract: Objectives: Placement of short endosseous implants represents a valid treatment in the setting of limited alveolar bone height. This study’s objectives were: to estimate the 5 year clinical survival of Bicon™ short implant and to evaluate radiographic bone level changes around 6 x 5.7mm implants in comparison with longer non-6 x 5.7mm implants.

Conclusion: Short implants with large diameter (6 x 5.7mm) have a long-term (>5-years) survival rate and crestal bone level maintenance similar to that observed for non - 6 x 5.7mm implants. The results of this radiographic study support the hypothesis that 6 x 5.7mm implants can be successfully used in edentulous maxillary and mandibular areas with limited bone height.

  Download PDF

Sinus Augmentation Procedure Using Beta-Tricalcium-Phosphate:
Histological Analysis of Grafted Bone at Time of Implant Placement

American Academy of Periodontology 94th Annual Meeting & Exhibition | Seattle, WA | September, 2008
Ulrike Schulze-Späte¹, Thomas Dietrich¹, ², Justine Dobeck³, Rayyan Kayal¹, Adrian Time¹, Ziedonis Skobe³, Serge Dibart^1
1Department of Periodontology and Oral Biology, Goldman School of Dental Medicine, Boston University, Boston, MA,
²University of Birmingham, UK
³The Forsyth Institute, Boston, MA

Background: Implant placement in the edentulous maxilla often represents a clinical challenge due to insufficient bone height after crestal bone resorption. Several graft materials have been evaluated for augmenting the maxillary sinus in order to compensate for the lost vertical dimension. Allografts are readily available, there is no risk of disease transmission and they do not require a second site surgery.The aim of this study was to evaluate the development and maturation of augmented bone in the maxillary sinus using beta-tricalcium phosphate.

Material and methods: Patients (n=10, female: 4/male 6, age 30-64) with the need for rehabilitation of their dentition in the posterior maxilla and no present medical contraindications were included in the study. Beta-tricalcium phosphate (SynthoGraft, Bicon, Boston, MA) mixed with the patient’s blood was implanted into the sinus cavity, which was accessed using a lateral window technique. 6-8 month post sinus elevation, bone biopsies were taken and implants were placed simultaneously. All specimens were demineralized and subjected to staining procedures (H&E, Goldner's staining, TRAP). Slides were analyzed using lightmicroscopy for total surface area, the surface area that consisted of bone and the surface area that consisted of graft material (all in mm2 and expressed as % of the total surface.). Osteoclasts were identifiedand counted as number per mm2.

Results: All implants were placed achieving primary stability and restored 4 months after placement. H&E and Goldner's stainings demonstrated the presence of vital woven bone in the grafted area withonly a few remaining graft particles (total bone surface: 31.3%±15.8% at 6 month and 36.4%±5.4% at 8 month, total graft surface:13.9%± 4.7%at 6 month and 9.6%±4.8%). In addition, TRAP staining revealed presence of osteoclasts surrounding those particles (osteoclast number:1.23±0.25 per mm2 at 6 month and 1.4±0.4 per mm2 at 8 month). A lack of inflammatory reaction was noticed with the use of this graft material. During 12 month follow up, no implant failure or complications were observed.

Conclusions: Beta-tricalcium-phosphate has the advantage of exhibiting no risks of disease transmission and can be available in unlimited quantities. It is clinically easy to use, having great handling properties and appears to cause no persistent inflammatory reaction insurrounding bone. Overall this material seems to provide adequate stability at time of implant placement. Therefore, augmentation of the maxillary sinus with beta-tricalciumphosphate represents a viable option for increasing vertical bone height in the posterior maxilla prior to implant placement.

  Download PDF

Crown-Implant Ratios of 6mm Length Implants

Academy of Osseointegration 2008 Annual Meeting | Boston, MA | February, 2008
Hardeep (Bobby) Birdi, DMD • John Schulte, DDS, MSD • Alejandro Rodriguez-Kovacs, DDS • Meghan Weed, RDH • Sung-Kiang Chuang, DMD, MD
University of Minnesota School of Dentistry

Introduction: Unfavorable crown-implant ratios have not yet been established. Still, excessive crown-implant ratios have been cited in the literature as being detrimental to long term implant success. The primary aim of this study was to determine the crown/implant ratios of single implant-supported fixed restorations on 6mm length implants in a clinical practice, and to evaluate the health of these implants via mesial and distal bone levels. Additionally, the relationship between crown-implant ratio and proximal bone levels was to be evaluated.

Material and methods: In this retrospective cohort study the cohort was composed of 314 patients possessing at least one single 6mm length plateau design implant supported fixed restoration which had been surgically placed between Feb 1997 and Dec 2005. A chart review was performed to acquire radiographs in which both the entire crown and implant were visible. The length of the crown and implant were measured directly from the radiographs using consistent magnification to calculate the crown-implant ratio. Also, the mesial and distal bone levels were measured using 3 times magnification and mathematically corrected for distortion. The last available radiograph was used to measure bone levels. Follow-up time was calculated from the day of implant placement, to the last available radiograph. Statistical analyses using analysis of variance mixed models were used.

Results: Data from 534 single implant supported fixed restorations were tabulated and included in the study. The mean (SD) follow-up time was 15.8 (19.2) months, with a range of 0.01 to 99.2 months. The mean crown length (SD) was 13.3 (2.7) mm, with a range of 2.4 to 21.7 mm. The mean (SD) crown-implant ratio was 1.97 (0.4) and ranged from 0.36 to 3.2. The average mesial and distal bone levels (SD) measured from the final radiographs were -0.2 (0.7) mm and -0.2 (0.9) mm respectively. There was no statistically significant relationship between increasing crown-implant ratios and decreasing mesial and distal crestal bone levels around the implant with p-values of 0.94 and 0.57 respectively.

Conclusions: The results of this study suggest crown-implant ratios do not affect long term success of 6mm length implants. Also, there are no associations between crown-implant ratio and crestal bone levels.

  Download PDF

Preliminary Results of the Survival of 5 x 6 mm Implants

Academy of Osseointegration 2008 Annual Meeting | Boston, MA | February, 2008
Augusto Saldarriaga, DDS • Michael R. Markiewicz, BS • John Schulte, DDS, MDS • Meghan Weed, RDH • Sung-Kiang Chuang, DMD, MD
University of Minnesota School of Dentistry

Introduction: Manufacturers of dental implants have introduced short implants for use in areas of vertical alveolar bone deficiency. The literature regarding the survival of short implants is mixed. Recent modifications in the geometric shape and surface treatments of short implants may contribute to a rate of survival comparable to their longer counterparts. The objective of this study was to determine the short term survival of a 5 x 6 mm plateau designed dental implant.

Methods: A retrospective cohort study design was used. The cohort consisted of patients who received one or more 5 x 6 mm plateau designed implant inserted between January 2005 and August 2006 at a private practice clinic. A chart review was conducted to acquire data on patient demographics, implant location, bone density, length of time in function and/or implant failure. The primary outcome variable was implant failure. Survival time was defined as the time between the date of implant placement and last appointment or the date of implant removal for any reason. Descriptive statistics are reported.

Results: The sample included 542 implants placed in 324 patients (52.8% female). Mean patient age was 56.6 + 13.1 years. All 5 x 6 mm plateau designed implants were placed using a two stage technique. 301 (56%) implants were placed in bone density three and 151 (28%) implants in bone density four. 226 (41%) were placed in the posterior maxilla and 265 (49%) in the posterior mandible. The average follow-up time the implants were in function was 13.3 + 8.4 months, range 0.1 to 30.4 months. 35 failures were recorded for a survival rate of 92.1%. 20 (57%) of the failed implants were placed in type three bone density and 13 (37%) in type four density bone. 17 (49%) of the failures were in the posterior maxilla and 11 (31%) in the posterior mandible.

Conclusion: The short term survival of the 5 x 6 mm plateau designed implant is encouraging. Additional observation time is necessary to establish long term survival rates.

  Download PDF

Crestal Bone Level and its Association With Varying Densities of Bone

Academy of Osseointegration 2008 Annual Meeting | Boston, MA | February, 2008
Sujey Rodriguez-Lozano, DDS • John Schulte, DDS, MDS • Meghan Weed, RDH • Sung-Kiang Chuang, DMD, MD
Graduate Prosthodontics, University of Minnesota School of Dentistry

Introduction: Crestal bone levels associated with dental implants are an indication of the health or status of the implant.

Purpose: The purpose of this study was to evaluate crestal bone levels on plateau designed implants in various densities of bone.

Methods: A case series study design was used. The sample was composed of patients who had single tooth implant supported restorations placed between February 1997 and August 2006 with densities of bone information available in the charts. Bone levels on the mesial and distal surfaces of the implants were established by direct measurement from the top of the implant to the radiographic position of the bone on the implant surface. Radiographs were mathematically corrected for distortion. Bone density was determined objectively by examination of the bone which collected on the flute of the reamer during preparation of the osteotomy. Type I bone was characterized by bone which had minimal blood content, type II bone by blood wetted bone in the reamer, type III bone by a partially filled reamer of blood wetted bone and type IV bone as a reamer devoid of bone. Descriptive statistics were computed and data was analyzed with analysis of variance mixed models.

Results: The sample consisted of 214 patients (50.0% females), Average age of the patients was 56.6 years. 264 plateau designed implants were included in this study. 50 implants were placed in type II bone density, 117 implants were placed in type III bone density and 97 were placed in type bone IV bone density. The mean age of implants was 2.3 ± .8 years. Mesial and distal bone levels in each of the 4 types of densities was reported as: For density type II: mesial -.9 ± .6 mm and distal -.9 ± .6 mm. For density type III: mesial -.8 ± .7 mm and distal -.8 ± .9 mm. For density type IV: mesial -.8 ± .6 mm and distal -.8 ± .5 mm. Statistical testing reveals no statistically significant differences in mesial bone levels (P=0.38) and distal bone levels (P=0.79) between the three groups of bone densities.

Conclusions: This study suggests that the crestal bone loss associated with the plateau designed implant is well within guidelines established in the literature. Secondly, there is no statistically significant difference in the crestal bone levels when comparing various densities of bone. The results of the study are relevant only to the plateau design implant.

  Download PDF

In Vivo Evaluation of Implant Length and Surface Physico/Chemistry Characteristics in Biomechanical Anchorage in Plateau Root Form Implants. An Experimental Study in Beagle Dogs.

Academy of Osseointegration 2008 Annual Meeting | Boston, MA | February, 2008
Granato R, Marin C, Suzuki M, Gil JN, Coelho PG

Introduction: Since the implant surface is the first part of the implant that interacts with the host, significant attention has been devoted towards increasing the biocompatibility and osseoconductivity of implant surfaces. Surface modification approaches have been successful in increasing the host response to surgical implants, resulting in higher bone-to-implant contact (BIC) and higher bone mechanical properties at early implantation times. Among surface chemistry modifications, the incorporation of Ca- and P-based bioceramic onto the implant surfaces through various manufacturing processes has been investigated throughout the last two decades. These basic and clinical investigations have shown that bioceramic coated implants presented higher degrees of osseoconductivity and attained higher degrees of biomechanical fixation at earlier implantation times compared to uncoated implants. The objective of this study was to determine the influence of implant length and surface chemistry (Alumina-blasted/acid-etched (AB/AE) vs. Nanotite (Na) bioceramic deposition) on the biomechanical fixation of plateu root form implants in a beagle dog tibia model.

Methods: 4.5x11 mm (L) and 4.5x6 mm (S) plateau root form implants of AB/AE and Na surfaces were placed bilaterally along the proximal tibia of 6 beagle dogs and remained for 2 and 4 weeks in vivo (n=9 per implant length, surface, and time in vivo).(Fig. 1 and 2) Following euthanization, the implants were torqued to interface failure at ~0.445 radians/sec.(Fig. 3 and 4) ANOVA was utilized to determine the effects of implant length, surface, and time in vivo as (independent variables) on torque to interface failure (dependent variable). One-wayANOVAwas utilized for direct comparison between groups.A95% level of significance was used.

Results: trans-surgical bone preparation showed that L implants engaged two bone corticals whereas S implants engaged one cortical. ANOVA showed that all independent variables presented a significant effect in torque to interface (Ncm) failure: Implant length (P<0.0005, S=43.75±11.02 , L=72.02±10.54 ), implant surface (P<0.0000, AB/AE=34.93±10.85 , Na=80.84±10.7 ), and time in vivo (P<0.002, 2W= 45.51±10.7 , 4W=70.27±10.85 ). One-way ANOVA showed significant differences between groups (P<0.0000, see Table 01).

Conclusions: According to the results obtained, the Nanothickness bioceramic surface coating played a significant role on biomechanical fixation of L and S implants at both times in vivo. While ANOVA showed a significant effect of implant length on biomechanical fixation, direct comparison between groups showed that this difference was larger for Nanotite coated implants, and not significantly different for uncoated implants.

  Download PDF

A Comparison of Crestal Bone Levels in Immediate Versus Delayed Loaded Implants

Academy of Osseointegration 2008 Annual Meeting | Boston, MA | February, 2008
Cary D. McNeil, DDS • John K. Schulte, DDS, MSD • Meghan Weed, RDH • Sung-Kiang Chuang, DMD, MD
University of Minnesota School of Dentistry

Introduction: The results of implant survival studies as they relate to immediate versus delayed loading are inconclusive. Some report greater failure rates with immediate loading and others show no difference between the two procedures. Implant failure is often associated with excessive bone loss over time. As a result, bone loss over time may be a critical measurement of implant health. The objective of this study was to determine if there were differences in crestal bone levels over time with immediately loaded plateau design implants compared with delayed loaded plateau design implants.

Methods: A retrospective cohort study was used. The cohort consisted of patients who received a single tooth plateau designed implant, immediate or delayed loading, between January 1997 and July 2005. Digital radiographs were retrieved from patient records. Mesial and distal bone levels were measured directly on the radiographs using 3x magnification and mathematically corrected for distortion. Changes in bone levels over time were calculated by comparing levels at post-integration with the last available film. Analysis of variance mixed models adjusted for clustered effects was used to test for statistical significance between the two groups.

Results: A total of 483 implants were included in this study. The initial radiographic measurement of bone levels was set at 10 months after implant placement and was followed with a mean follow-up time of 19.3 months. The mean patient age was 55.3 years and 48.9% were female. There were 204 implants which were immediately loaded and 278 implants which were delayed loaded. Mean changes in mesial and distal bone levels for the immediately loaded implants were 0.19mm ± 0.7mm and 0.27mm ± 0.7mm respectively. For the delayed loaded implants, the mean mesial and distal bone levels were 0.14mm ± 0.7mm and 0.09mm ± 0.6mm respectively. No statistically significant differences were found in crestal bone levels over time in the immediately loaded implants compared with the delayed loaded implants (mesial changes in bone levels p=0.70, distal changes in bone levels p=0.12).

Conclusions: Using bone level changes over time as a criterion to measure implant health, there was no statistically significant difference between immediate and delayed loaded plateau design implants. An increase in bone levels was recorded for both groups.

  Download PDF

Immediate- Versus Delayed-Implant Placement Following Tooth Extraction: Survival Analyses and Factors Associated With Survival

J Oral Maxillofac Surg | March, 2007
Michael R. Markiewicz, BS, 71 Bory Dr, Depew, NY,14043 (Markiewicz MR; Chuang SK; Weed M; Dodson TB)

Statement of the Problem: Conventional implant practice dictates a delay between tooth extraction and implant placement. Some investigators advocate inserting implants immediately after the tooth is extracted. Advantages of immediate over delayed implant placement following extraction include shorter treatment time, fewer visits, and a diminished time period of functional and esthetic deficiency. Offsetting the advantages of immediate implant placement may be an increased risk for implant failure.

Purpose: The purpose of this study was to answer the following clinical question: “Among implants inserted, do those placed immediately after tooth extraction, when compared to those placed at some time after tooth extraction, have a decreased likelihood of survival one-year after insertion?” A secondary purpose was to identify prognostic factors associated with one-year implant survival.

Materials and Methods: Using a retrospective cohort design, the investigators enrolled a sample of subjects having at least one implant inserted between 7/1/01-8/31/05 at the Implant Dentistry Centre, Boston, MA. The primary predictor variable was the timing of implant placement following extraction (immediate vs delayed). An immediate implant was defined as an implant inserted immediately following the extraction. A delayed implant was defined as an implant inserted at any time after the day of tooth extraction. The outcome variable was implant survival at one-year after insertion. Secondary explanatory variables were categorized as demographic, health status (e.g. ASA status, tobacco use), implant-specific (diameter, length, coating), anatomic (location), and perioperative variables (e.g. staging, dentoalveolar reconstructive procedures, antibiotic use, implant stability at stage 2). Descriptive statistics, Kaplan- Meir survival analysis, as well as univariate and multivariate Cox proportional hazards regression analyses were completed using SAS (version 9, SAS Institute Inc, Cary, NC). Level of statistical significance was set apriori at a = 0.05.

Results: The study sample was composed of 161 patients having 963 implants inserted (412 immediate-placed vs. 551 delayed-placed). The mean duration of clinical follow-up amongst the study sample was 26.2 months. The one-year unadjusted Kaplan-Meier survival rates for immediate- and delayed-placed implants were 87.5% and 92.8%, respectively (p_0.06). Multivariate analysis revealed no statistically significant difference in overall follow-up survival time between immediate- and delayed-placed implants (p_0.4) (Hazard Ratio _ 0.7, 95%CI: 0.3, 1.6). After adjusting for potential confounders, factors significantly associated with implant survival (p_0.05) were implant length, bone quality at the implant site, coated implants, two-stage implant placement (insertion and subsequent uncovering at a future visit), and implant stability at the uncovering stage of treatment.

Conclusions: Implant survival at one year was not statistically statistically different between implants placed immediately after tooth extraction and those placed in a delayed manner in the unadjusted or adjusted analyses. The data support the hypothesis that there is no significant difference in survival between implants immediately or delayed placed following tooth extraction. After adjusting for potential confounders, the investigators found implant staging, implant length, bone quality at the implant site, and coated implants were associated with an increased likelihood of implant survival at five years post-insertion.

References: Casap N, Zeltser C, Wexler A, Tarazi E, Zeltser R. Immediate placement of dental implants into debrided infected dentoalveolar sockets. J Oral Maxillofac Surg. 2007 Mar; 65(3):384-92 Lindeboom JA, Tjiook Y, Kroon FH. Immediate placement of implants in periapical infected sites: a prospective randomized study in 50 patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006 Jun;101(6):705-10

  Download PDF

Histomorphometry of Explanted Dental Implants

IADR | New Orleans, LA | March, 2007
J. Lemons, M. Anabtawi, P. Beck, and V. Morgan
Department of Prosthodontics, School of Dentistry University of Alabama at Birmingham

Objective: The significant success (%) and longevities of root form dental implants affords opportunities to evaluate and classify device-to-bone interfaces. These opportunities are based on a small percentage that come to revision. Histomorphometric analyses of human explants permits multiple comparisons including in vitro and laboratory in vivo study outcomes.

Methods: A clinical group (headed by VM) have removed root form implants, where indicated clinically, by Magnitudes of osseous integration from three time periods (about 2, 5 and 10 years) are shown in Figure 2 (A-C) trephine osteotomy. The implant body and bone remain in bloc and specimens were immediately fixed in 10% buffered formalin and transferred with selected records for analysis. Specimens were: macrophotographed, evaluated stereomicroscopically; oriented, embedded; prepared by Exakt® sectioning; stained; and evaluated along longitudinal mid-line thin (20-50 micrometer) sections by Bioquant® imaging for bone quality, quantity, and specific anatomical characteristics.

Results: Eighty* plateau-type design received from one source over the past 3 years. Specimens evaluated by staff and students resulted in: (1) adequate bone for 41 longitudinal section histomorphometric analyses; (2) percent bone integration from 5 to 95% that was not significantly correlated (p>0.05) with in vivo factors other than anatomical location; and (3) interfacial bone structures of a mature and osteonal-type anatomy reported previously1. These results support that dental implant-to-bone interfaces can be stable over time and function with bone remodeling leading to a functional anatomy that is characteristic of the implant design. Comparative analyses with screw-type designs of the same biomaterial are scheduled.

Conclusions: (1) en bloc explants from in vivo functional periods from 3 to 126 months showed osseointegration percentages from 5 to 95%; and (2) the bone anatomy was a mature osteonal type structure, characteristic of plateau type implant designs.

Partial student support from Bicon, Boston, MA is acknowledged.
Lemons, J, J Oral Imp, 2004 and in Davies, J. Ed., Bone Engineering, 2000.

  Download PDF

Histological Analysis for forty one retrieved dental implants

IADR | New Orleans, LA | March, 2007
Muna Anabtawi, Preston Beck, Al Bartolucci, Vincent Morgan, Jack Lemons
Department of Prosthodontics, School of Dentistry University of Alabama at Birmingham

Objectives: To analyze the anatomy and osseous integration status of the hard tissue interfaces for retrieved implants, and to interpret the clinical status of this specific implant patient population through correlating bone integration status and demographical data.

Methods: Eighty dental implants removed for clinical reasons were retrieved from patients over a 3 year period. Forty one explants were selected for histological analysis because they had adequate bone for longitudinal section analyses. Specimens were processed, embedded in plastic, and thin (20-30 micrometer) ground sections were made along the long axis of the implants. Specimens were stained with Sandersons’ Bone Stain. Blinded histomorphometric analysis was performed to measure the percentage of bone area between the plateaus and the bone/implant contact (BIC). Patient records (gender, date of birth, smoking status, time in vivo, type of implant surface, presence of augmentation, and position of the implants in the jaw) were collected and incorporated into the histomorphometric data; and statistical analysis was performed.

Results: There were no strong associations between any of the clinical, patient and implant variables and the bone area percentage and (BIC). In a multiple regression analysis adjusting for the available data, the anterior position was marginally significantly associated with higher percentage of bone and (BIC) (p=0.067). Performing a simple pair wise correlation, females had higher percentage of bone than males (p=0.0898).

Conclusions: The findings support that the success and failure can be caused by a combination of factors not associated with bone integration status. Revision procedures represent a small percentage of dental implants treatment and this study demonstrates that larger numbers of specimens will be required for statistical significance amongst the variables considered.

  Download PDF

Assessment of Periodontal Health Around Integrated Abutment Crowns

AAP Annual Meeting, San Diego, CA, September 2006.
Cheng, K.K., Chuang, S.K., Weed, M., Dibart, S.,

Background: The Integrated Abutment Crown™ (IAC) (Bicon, Boston MA) is a cementless, screwless implant-supported crown made from a polyceramic material, which is 80% glass and 20% PEX resin. Unlike the porcelain fused to metal crown (PFM), the IAC restoration is fused to the abutment thus eliminating the presence of a crown/abutment microgap. The purpose of the present investigation was to compare various periodontal parameters in patients with IAC, natural teeth (NT), NT restored with PFMs, and implants restored with PFMs.

Materials & Methods: A retrospective cohort study was conducted on patients evaluated from January, 2003 to April, 2005 at the Implant Dentistry Centre – Faulkner Hospital (IDC-FH), Boston, MA. Natural teeth/implants of these patients were separated into 4 groups: Group 1 (NT), Group 2 (NT/PFMs), Group 3 (implants/PFMs) and Group 4 (implants/IACs). Periodontal parameters including modified plaque index (MPI), sulcus bleeding index (SBI), gingival index (GI), and the average of 6 probing depths (PD) from each tooth or implant (MF, F, DF, ML, L, and DL) were recorded at initial and final examinations. Linear mixed-effects models were used to evaluate the associations between the four groups (the main predictor) and clinical periodontal parameters over the follow-up time. A p-value < 0.05 was considered statistically significant.

Results: The sample included 50 patients (22 males, 28 females) with a mean age of 64.2 years (range = 31.65 - 95.16 years) that were observed over a mean follow-up period of 23.07 months (range of 9.99 -26.28 months). A total number of 375 teeth/implants were divided into: Group 1 (105 NT), Group 2 (63 NT/PFMs), Group 3 (68 implants/PFMs) and Group 4 (139 implants/IACs). The mean changes in clinical periodontal parameters of each group were compared to a reference group (Group 1). Gingival index: Group 3 > 2 > 1 > 4. Average probing depth: Group 1 > 2 > 4 (p < 0.05) = 3 (p < 0.05). (Difference between group 3 and 4 was not statistically significant.) Sulcus bleeding index: Group 4 > 2 > 1 > 3. Modified plaque index: Group 4 (p < 0.05) > 2 > 1 > 3.

Conclusion: Group 4 had the most significant decrease in GI compared to the other groups and performed similarly to Group 3 in terms of probing depths. There were no statistical differences with respect to mean change of SBI among the four groups. Group 4 was found to have a significantly higher MPI score compared to Group 1. Further studies evaluating the plaque composition will be necessary in the near future to explain these findings.

An Innovative Immediate Stabilization Technique For Dental Implants

FDI World Dental Congress | Shenzhen, China | September, 2006
Drauseo Speratti, DDS; Meghan Weed, RDH; S.K. Chuang, DMD

Introduction: Several techniques for the immediate stabilization and functioning of dental implants have been used and described over the years. This study demonstrates how effective this procedure can be done, showing the ease with which quality aesthetic results can be achieved without any additional comprehensive laboratory procedures for the provisional phase. A screwless implant/abutment connection improves the efficiency and effectiveness of the procedures. Regular restorative procedures provide the final restoration.

Materials & Methods: The sample was compose of 505 patients who had a total of 1086 implants placed. We used a retrospective cohort study design including patients who had one or more implants placed using the technique of Immediate Stabilization or Loading between November 1999 and January 2006.

Results: The overall lifetime proportional rate was 91.61%. Conclusion: This study demonstrates how this technique can be efficient and cost effective, allowing patients to function without the need for removable appliances during healing period, significantly reducing operative time.

Radiographic Bone Levels on 6x5.7 mm Implants: A 5-Year Follow-up Study

AAP Annual Meeting | San Diego, CA | September, 2006
Caterina Venuleo, D.D.S., Boston University, Goldman School of Dental Medicine, Department of Periodontology; Sung-Kiang Chuang, Harvard University, School of Dental Medicine; Meghan Weed; Rainier Urdaneta, Harvard University; Serge Dibart, Boston University, Goldman School of Dental Medicine, Dept. Periodontology. This study was supported by Educational Grant Bicon LLC (Boston, MA).

Background: Placement of short endosseous implants represents a valid tratment alternative to more complex surgical techniques such as ridge augmentation/sinus lift implant-associated procedures, in the setting of limited alveolar bone height. This study's objectives were: 1) to estimate the 5-year clinical survival of Bicon 6x5.7mm implant 2) to evaluate radiographic bone level changes around 6x5.7mm implants in comparison with Bicon longer non-6x5.7mm implants.

Methods: A retrospective cohort study design was used. The cohort was composed of patients who had at least one 6x5.7mm implant placed for 5 years, at least one non-6x5.7mm implant, and who were willing to return to the dental office for radiographic evaluation. A total of 141 implants, 32 6x5.7mm (test group) and 109 non-6x5.7mm (control group), were placed in 20 patients (12 males and 8 females) with a mean age of 59.2 +/- 11.8 years. Mean length of non-6x5.7mm implants was 9.7 mm, (range: 8 mm to 14 mm, mean diameter was 4.39 mm (range: 3.5 mm to 5 mm). Bone loss, defined as the vertical difference in crestal bone level measurements from the baseline (day of implant placement) to 5 years follow-up, was digitally determined on periapical radiographs. Generalized linear mixed models were used for the statistical analysis.

Results: Five-years survival rates for test and control groups were 90.3 % and 97.7% respectively, but this difference was not statistically significant (p>0.05). There was no significant difference between the two groups with regard to mean changes of radiographic bone levels.

Conclusion: Short implants with large diameter (6x5.7mm) have a long-term (>5 years) survival rate and crestal bone level maintenance similar to that observed for non-6x5.7mm implants. The results of this radiographic study support the hypothesis that 6x5.7mm implants can be successfully used in edentulous maxillary and mandibular areas with limited bone height.