Presentation on theme: "M. MARINCOLA* 1, S. DIBART 2, M.L. WARBINGTON 2, Z. SKOBE 3, R. URDANETA 4, and S.-K. CHUANG 5 1 University of Cartagena, Rome, Italy, 2 Boston University,"— Presentation transcript:
M. MARINCOLA* 1, S. DIBART 2, M.L. WARBINGTON 2, Z. SKOBE 3, R. URDANETA 4, and S.-K. CHUANG 5 1 University of Cartagena, Rome, Italy, 2 Boston University, Boston MA, 3 Forsyth Institute, Boston, MA, 4 Concord Dental Associates, Concord, MA and Harvard School of Dental Medicine Boston, MA, 5 Harvard School of Public Health, Boston, MA INTRODUCTION CONCLUSIONS Bacterial Adhesion on Integrated Abutment Crowns TM. In Vivo Study (II) RESULTS The trauma surrounding the partial or total loss of the natural dentition to periodontal diseases or caries has been alleviated in the last decades by the introduction of the concept of predictable osseointegration to the dental profession. Successfully osseointegrated dental implants have revolutionized the practice of late 20 th century dentistry. They provided patients with the ability to have fixed restorations instead of removable devices, and help avoid the mutilation of adjacent natural teeth when a 3 unit fixed partial restoration was envisioned. As with all prosthetic restorations in the oral cavity, they are subject to factors impacting esthetics, function, and periodontal health. Periodontal health or peri-implant health is the most critical aspect of this trilogy, since compromising it could mean potentially disastrous effects on esthetics and function. The tissues supporting dental implants are susceptible to disease (peri-implantitis), which in turn could lead to bone loss and implant failure. The disease process is initiated by microorganisms that are present in the periodontal plaque. These bacteria and their by- products (enzymes, toxins, metabolic products), in the susceptible host, will start a whole cascade of events that will lead to periodontal tissue damage. bacteria need to adhere to a solid surface (i.e. prosthetic or natural crown, soft tissue etc.) in their primary phase of colonization before causing the disease. A restoration material that would repel or cause bacteria to adhere minimally would be a plus in preventing disease. In June 2001, Bicon Inc. (Boston, MA) introduced the Integrated Abutment Crown (IAC). This is a new concept where the implant abutment and the crown material are one integral unit (Fig.1). A poly-ceramic material such as Diamond Crown (DRM Research Labs Inc., Branford, CT) is fused onto the coronal post of a titanium alloy abutment. The IAC is then placed directly into the well of the implant, there is no need for cementation or screw retention. The goal of the present investigation was to determine if the Diamond Crown material used to make Bicons IAC is less susceptible to harbor/attract bacterial plaque than All Ceramic (AC) or Porcelain Fused to Metal (PFM) crowns METHODS # A ABSTRACT. Objectives: The purpose of this study was to compare the subgingival microbiota present on implant supported Integrated Abutment Crowns (IAC) and natural teeth in vivo. Material and Methods: A cross-sectional study design was utilized with patients selected from the patient pool at the implant dentistry center at Faulkner Hospital (Boston, MA). Thirty-one patients (13 males and 18 females) were selected, mean age years (range to years) of which 4 were smokers. Selection requirements were: Patients had IAC crowns placed at least 6 months ago and had not taken antibiotics 3 months prior evaluation. Gingival index (GI), modified bleeding index (MBI), subgingival plaque samples and clinical photographs were taken on at least 1 IAC and the natural contralateral tooth on each patient. The subgingival plaque samples were taken from the mesial side of the IAC or natural teeth and put in an Eppendorf tube containing ml Tris-EDTA. The samples were then hybridized with 12 whole chromosomal probes to Tannerella forsythensis, Prevotella intermedia, Campylobacter rectus, Fusobacterium nucleatum, Actinomyes odontolyticus, A. naeslundii, Streptococcus sanguis, S. intermedius, Actinobacillus actinomycetemcomitans serotype b, Streptococcus oralis, Porphyromonas gingivalis and Prevotella intermedi, using the checkerboard DNA-DNA hybridization method. The descriptive statistics and generalized linear mixed models (GLMM) accounted for intra-cluster correlation within the same patient were utilized using SAS-PC (version 8.2, 2001) Results: IAC were noted to have less GI and MBI compared with natural teeth but were not statistically significant (p>0.05). There were no statistical differences (p>0.05) in all the various colonies count between IAC and the natural teeth. Conclusions: The IAC showed striking similarities with the natural tooth in terms of subgingival bacteria plaque count and composition. The IAC also showed lower GI and MBI indices. Supported by a research grant from Bicon, Inc.(MM, SD), OMSF Foundation Fellowship in Clinical Investigation (SKC) The results of this in vitro and in vivo study seem to show that bacterial presence is inevitable on any type of prosthetic restoration. However the IAC design seems to go toward reducing this eventuality by eliminating the gap between implant abutment and crown, and providing a smooth cervical interface. Figure 2. Integrated abutment crown (tooth #9) being inserted into the implant fixture, in a clinical setting. Figure 3. Integrated abutment crown after insertion. Notice the quality of the gingival margin surrounding the crown. After approval by the Institutional Review Board of the Faulkner Hospital (Boston, MA), a cross-sectional study design was utilized with patients selected from the patient pool at the Implant Dentistry Center at Faulkner hospital. 31 patients (13 males, 18 females) were selected, mean age years (range to years). The selection requirements were: patients had to be in good general and periodontal health, had IAC crowns placed at least 6 months prior to bacterial sampling, and had not taken antibiotics 3 months prior evaluation. Using a split mouth design, gingival index (GI), sulcus bleeding index (SBI), pocket depths, subgingival plaque samples and clinical photographs were taken on at least 1 IAC and the natural contralateral tooth on each patient. All measurements were carried out by the same clinician. Bacterial plaque collection and microbiological assessment: Using the protocol described by Socransky et al., 6 after isolating the IAC (s) and contralateral natural teeth with cotton rolls, supragingival plaque was discarded. The subgingival plaque samples were then collected with a sterile Gracey curette from the mesial side of the tested teeth and placed in separate Eppendorf tube containing 0.15 ml TE. Then 0.15 ml of 0.5 M NaOH was added to each sample and boiled in a water bath for 5 min. The neutralized and denatured DNA samples as well as the known amount of bacterial DNA corresponding to 10 5 and 10 6 cells for the DNA probes to be used were placed into a Minislot and fixed onto a nylon membrane by exposure to ultraviolet light followed by baking at 120˚C for 20 min. The membranes with fixed DNA were placed in a Miniblotter 45 and incubated with 10 whole chromosomal DNA probes to the same 10 bacterial species used in the in vitro experiment: Tannerella forsythensis, Prevotella intermedia, Campylobacter rectus, Fusobacterium nucleatum, Actinomyces odontolyticus, A. naeslundii, Streptococcus intermedius, S. oralis Actinobacillus actinomycetemcomitans serotype b, Porphyromonas gingivalis. Digoxin labeled, whole chromosomal probes were prepared using a random primer technique. Signals were detected by chemiluminescence. The sensitivity of this assay was adjusted to permit detection of 10 4 cells of a given species. Signals were evaluated visually by comparison with the standards for the test species. This is the scale that was used to record the data: 0, No signal detected; cells. Statistical analysis. A database was created using Excel (Microsoft 2000, Seattle, WA) with the appropriate checks to identify errors. Descriptive statistics were computed for all of the study variables. Assessing correlated outcome measurements with various variables: gingival index (GI), sulcus bleeding indices (SBI), and probing depth (PROBE)) were utilized using generalized linear mixed models (GLMM) approach (PROC MIXED) with exchangeable correlation matrices adjusted for clustered observations within the same patient. Statistical computing analyses utilized the SAS (Version 8.2, Cary, North Carolina, 2001) programming environment in the PC-DOS operating system. Statistical analysis. A database was created using Excel (Microsoft 2000, Seattle, WA) with the appropriate checks to identify errors. Descriptive statistics were computed for all of the study variables. Assessing correlated outcome measurements with various variables: gingival index (GI), sulcus bleeding indices (SBI), and probing depth (PROBE)) were utilized using generalized linear mixed models (GLMM) approach (PROC MIXED) with exchangeable correlation matrices adjusted for clustered observations within the same patient. Statistical computing analyses utilized the SAS (Version 8.2, Cary, North Carolina, 2001) programming environment in the PC-DOS operating system. Figure 1. Clinical photograph of a Bicon Integrated Abutment Crown. The porcelain is fused to the abutment, there is no cementation. PARAMETERSNatural TeethIAC(s)TOTAL GI = 020 (60.0%)45 (72.6%)65 GI = 112 (35.2%)16 (25.8%)28 GI = 22 (5.8%)1 (1.6%)3 GI = 3000 TOTAL Table 1. Frequency Distribution of Gingival Index (GI), inflammation severity for Natural Teeth and IAC(s). 0= No inflammation, 1= Mild, 2=Moderate, 3=Severe. PARAMETERSNatural TeethIAC(s)TOTAL SBI = 026 (76.5%)53 (83.9%)78 SBI = 17 (20.5%)9 (14%16 SBI = 21 (3%)1 (1.6%)2 SBI = 3000 TOTAL Table 2. Frequency Distribution of Sulcus Bleeding Index (SBI) severity for Natural Teeth and IAC(s). 0= No bleeding after probing, 1= Isolated bleeding spots visible, 2= Blood forms a confluent red line on margin, 3= Heavy or profuse bleeding Thirty one patients (13 males and 18 females) were selected, mean age years (range to years) of which 4 were smokers. A total of 96 observations (34 natural teeth and 62 IAC) were recorded. IAC(s) were noted to have statistically significant less GI scores compared to natural teeth (Table 1) (p=0.02). The bleeding indices on the facial aspect of the IAC compared with natural teeth tended to be slightly less but were not statistically significant (Table 2) (p=0.39). The probing depth of the IAC on the facial aspect compared to the natural teeth tended to have statistically significant higher probing depth (p 0.05). Comparing the IAC to the natural tooth in vivo, the IAC were noted to have less GI and SBI scores compared to the natural teeth; but this was not statistically significant (p>0.05). With regards to the subgingival microbiota, there were striking similarities between IAC and natural teeth. Prevotella intermedia, Fusobacterium nucleatum, Streptococcus sanguis and streptococcus oralis were encountered in lower numbers when compared to the natural teeth. However this was not statistically significant.