Dental Implants Therapy - Essay Example

Dental Implants Dental implant therapy is a common therapeutic approach to tooth loss by extraction. Current standards of therapeutic success have expanded previous measures of therapeutic outcome. Although the survival of the implant itself remains an important parameter of outcome assessment, additional measures involving a comprehensive restoration approach to dental health and aesthetics comprise therapeutic assessment standards. There are many anatomical and environmental parameters that play a role in determining optimal dental implantation outcomes. The following is a summary of four research review articles that address clinical research data relevant to this important dental procedure. A 10 year prospective clinical research study by Karoussis et al (2004) evaluated the periodontal and peri-implant conditions in a cohort of 89 edentulous patients (mean age 58.9 years) in order to assess the environmental, physiological and radiographic changes in the dental implants over a long period of time post-implantation. The rationale for this clinical research study involves the need to establish reliable data relevant to the use of dental implants in patients who have had tooth extractions. These types of data are difficult to obtain since they require long term assessments of patients who have received dental implants. These longitudinal single subject studies also require recruitment of large patient cohorts and need to address physiological and environmental factors that affect long-term success rates for dental implant procedures. The study participants were evaluated at one year and again at 10 years post implantation to evaluate the changes periodontal peri-implant conditions in individual patients. This study also incorporated an evaluation of risk factors associated with sub-optimal patient outcome post-implantation. Patients recruited in this study had previously been treated for periodontal disease and also had received prosthetic structures such as fixed partial dentures and crowns. ITI dental implant system was used in all patients enrolled in this study. Within this cohort a total of 179 implants were assessed; the same number of control natural teeth were included as a basis of comparison. In addition, all remaining teeth were examined in these patients. Patient behavioral risk factors, particularly cigarette smoking, were also evaluated in this study. The data parameters assessed in this study included plaque index (PI) for teeth and modified plaque index (MPI) for implants, gingival index (GI) for teeth and modified bleeding index (MBI) for implants. Additional measurements included the distance between implant shoulder and mucosal margin (DIM), the distance between the cement-enamel junction (CEJ) and the gingival margin, the probing pocket depth (PPD), the probing attachment level (PAL), and bleeding on probing (BOP) for teeth and implants. Measurements were in millimeters and were carried out at four sites for each implant or tooth. Radiographic assessments included a measure of the distance between implant shoulder and clear bone to impact contact (DIB). Bothe mesial and distal measurements were made. Comparable measurements of the distance between the CEJ and crestal marginal bone were made in teeth. Bone height changes were also recorded. Statistic analyses utilized the Wilcoxin matched pairs sign rank test. The results of this extended longitudinal research study demonstrated a significant difference between the dental implants and the control teeth based on the radiologic parameters and other clinical assessment tools used in this study. The only parameters that were similar were the plaque index and recession for both dental implants and normal teeth. The data procured in this clinical research study were rigorously evaluated statistically using multiple regression analysis to assess the validity of associations between the observed peri-implant conditions and diagnostic parameters used in this evaluation. Approximately 70% of the original cohort subjects were analyzed over the 10 year study. The mean overall tooth loss during this period was one tooth per patient, with an absolute survival rate for teeth of 95%. Results showed that plaque index was similar for implants and control teeth and that the recession rates were similar for implants and natural teeth. In contrast PPD and PAL changed for the implants over the course of the study. The authors concluded that the data indicated a significant correlation between implant PAL and implant location, full mouth PPD and full mouth PAL on the side of the mouth. They also observed that implants in the maxilla were associated with a greater rate of detachment than implants in the mandible region. Higher rates of detachment were correlated with higher full-mouth PPD and higher full-mouth detachment rates. The authors further suggested that the observed 36% variability in implant survival rates in the study cohort could be largely attributed to these conditions. The PPD values at the implant site also correlated with the above parameters and were cited as responsible for 47% of the observed variability in long-term implant survival. The overriding conclusion was that the overall rate of implant and tooth loss was similar in individual patients. The most important environmental factor cited was smoking, which was associated with significantly greater alveolar bone loss in this group of patients. The results of this study further indicated that the probing attachment level (PAL) ten years post-implantation was correlated with the location of the implant site, the full mouth pocket probing depth (PPD) and the full mouth probing attachment level (PAL). In addition, the probing pocket depth (PPD) was correlated with the location of the implant, full mouth PPD and PAL. The environmental factors most significantly associated with marginal bone level 10 years post-implantation were cigarette smoking and the overall physical health of the subject. Other factors associated with marginal bone level were the site of implantation, full-mouth PAL and PPD changes occurring over the time course of the study. One of the environmental assessed was the relative health and degree of bacterial contamination of the periodontal tissues in comparison with the peri-implant site. Research data suggests that patients with periodentitis are at increased risk for the development of peri-implantitis. Patient risk factors include smoking, diabetes, radiation therapeutic and bacterial infections including periodentitis. The authors of this research study concluded that changes in the tissues at the site of dental implantation have a significant effect on the periodontal and peri-implant conditions. This research study addresses the issue of immediate dental implantation, in which dental implants are inserted immediately after tooth extraction. This procedural protocol may be contrasted with immediate-delayed implantation in which the dental implant is inserted following soft tissue healing over a period ranging from several weeks to several months. In contrast, delayed implants are defined as implants inserted significantly after the extraction site has completely healed. There is some controversy surrounding the optimal time of dental implantation following tooth extraction. It has been argued that immediate implantation may produce a shorter overall healing time and better results with regard to maintenance of bone height; however immediate implantation may also increase the risk of infection and a decreased success rate for implant survival. To address this question XXXXX et al conducted a clinical research study to assess the overall success, complications and patient satisfaction associated with implant procedures utilizing the immediate, immediate-delayed or delayed implantation protocols. This study involved an assessment of two separate randomized controlled clinical trials (RCT) with a study time of one year post-implantation. The first assessed immediate implants that were inserted at sites of periapical infections in comparison to delayed implant insertion in a cohort of 50 patients. The results of this study indicated that there were no significant difference between the groups who received immediate versus delayed implantation surgery in all measured parameters including implant survival, treatment complications including infection, and patient satisfaction. Patient satisfaction was measured using a questionnaire that addressed responses of study subjects to issues of pain, complications, function and aesthetics of dental implants. The second RCT involved an assessment of 46 patients who received either immediate or immediate-delayed dental implant procedures. The study results once again indicated that there was no significant difference between these two groups when assessed for dental implant survival, aesthetics, and medical complications. However, there were differences in patient satisfaction revealed by the results of these two RCTs. Patients in the delayed group felt that there was a very lung time interval; between extraction and dental implantation and were overall less satisfied with the treatment process and results than patients in the immediate–delayed group. In addition, independent assessment indicated that the level of the peri-implant marginal mucosa was superior in the immediate delayed group as compared to the delayed group. The authors concluded that, in the absence of observed increased risk of complications, the immediate and immediate delayed therapeutic implantation protocols may be superior to the delayed implantation procedure, given the higher rates of patient satisfaction, the absence of adverse complication associated with earlier implantation and the potential for better aesthetic results based on alveolar bone preservation. The clinical study by Renouard et al (2006) is a retrospective review designed to address the question of tooth and implant loss based on data collected from longitudinal prospective clinical research studies. The follow-up period was at least 10 years and only studies with less than 30% dropout rates were included for evaluation. A total of 53 studies that included numerous study designs carried out between 1990 and 2005 were included for assessment and involved an assessment of 476 subjects. Inclusion criteria were requirements for relevant data on implant dimensions (width and height). Short implants were defined as those with length of 8 mm or less. Wide implants were defined as those with 4.5mm diameter or greater. Narrow implants were defined as those with a diameter of less than 3.5mm. Other inclusion criteria were accurate documentation of implant survival rates and failure rates, and the requirement implantation was performed only at completely healed sites of tooth extraction. The longevity of dental implants has been the subject of numerous clinical research trials. In general, these constitute prospective longitudinal studies involving at least ten years follow-up. The general consensus of over 35 clinical studies of this type that involved over 3000 subjects was that the incidence of implant loss was between 1 and 18%, while the incidence of tooth loss in this group was between 1.3-3%. The rate of implant loss did not appear to be significantly related to bone density changes at the site of implantation. Clinical studies of the success rate and long-term survival rate for 2917 implants indicated that the standard length implants (13mm length) ranked in the middle between the short diameter implants (13mm diameter). Clinical research studies have attempted to evaluate the risk of implantation failure using short-length implants. These studies involved prospective multicenter studies and some have compared the relative utility of dual acid-etched implants with machine-surfaced implants. The comparative assessments of short to standard length implants utilized similar baseline criteria of location, width and restorative type. The assessment of approximately 3000 implants of DAE composition versus approximately 2500 of machine-surfaced composition demonstrated a 2.2% 5 year CSR difference between the machine –surfaced short versus standard length implants. There was a 7.1% difference in the posterior maxilla and 8.5% difference in the anterior maxilla. In the case of the DAE implants, there was no significant difference between standard and short-length implants (0.7%). In the category of machine-surface implants, a higher failure rate for short implants was reported for most studies with the lowest overall survival rate recorded at 75%. In contrast, survival rates for long length implants were recorded at 90% or greater by several large clinical research trials. However, the was great variation in study findings, such that four main conclusions could be drawn The first was short implants were inferior to long in regard to implant survival; the second was that despite the lower rate, their survival rates were in an acceptable range; the third was that dimension and survival were unrelated; and a set of studies concluded that their use could be optimized to approach the success rate of long dental implants. These variable results may be attributed to difference in implant composition such that machine-surfaced implants were documented to display a lower success rate, although these studies are contradictory as well. The anatomical requirements for short implant insertion may correlate with poorer outcome. Failure rates were also significantly higher using wide diameter implants versus narrow diameter, which also may relate to differences in the insertion site. Other reasons for failure may be the result of operator training deficits. More recent studies have reported significantly higher success rates with short implants. The results of this retrospective analysis suggested that, under optimal conditions for implantation, there is no statistical difference between survival rates of implants with differing dimensions. The authors stressed, however, that differences in sites of implantation may represent a primary cause of implant failure, but that the procedure may be useful even in cases where bone resorption and tissue injury have occurred, since alternative therapeutic protocol may not provide a better outcome. The authors concluded that adaptation of dental implant dimensions to the anatomical components at the site of implantation may represent an appropriate alternative to bone and tissue grafting or other remediation of implantation site. The retrospective study by Ong et al (2008) specifically addressed factors that may contribute to the loss of osteointegration following dental implantation. The purpose of the research study by was to assess the effects of periodintitis on the outcome of dental implantation procedures. This was a retrospective clinical study of research clinical trials (RCTs) that addressed this question with regards to the measured parameters of implant, survival, changes in bone level, and the occurrence of peri-implantitis. Failure may involve complications arising during or shortly after implantation or may occur significantly later due to the failure of the implant to become stably integrated into the oral tissues of the socket. Infections associated with peri-implantitis may complicate the successful integration of the dental implant. Moreover, patients with periodontitis may be at increased risk for the development of peri-implantitis as similar bacterial strains are believed to be responsible for these infections. Because periodontitis is a major cause of tooth loss requiring dental implants, it is of critical importance to assess the link between this disease and the successful outcome of dental implantation procedures. The research question addressed by the authors of this study involved an assessment of success rates of implantation procedures measured by implant survival and bone level changes as well as the occurrence of peri-dentitis in patients treated for periodontitis and patients who did not suffer from this disease based on clinical and radiographic evidence. This retrospective study involved an evaluation of longitudinal CRTs that were randomized and included cohort studies, case-control studies and case series. Only data collected at least 6 months post-implantation were considered. Studies involving complicated patient histories such as diabetes or cancer were excluded from this review; however, patients with all stages of periodontal disease were included in this study. Outcome measurements included implant survival post-implantation. The four assessment criteria were nature of study, population, interventions and outcome. Over 4,000 publications were accessed; of these, nine studies that met all of the inclusion criteria ware included in the retrospective assessment. These included two cohort studies, four case series including control groups and three studies that directly compared outcomes in patients treated for periodontitis and those who did not show signs of this disease. A total of 148 implants from 54 patients were placed in the treatment group and 147 implants from 64 patients were classified as negative for periodontitis. Almost all the studies (one exception) indicated that patients without periodontal disease fared better regarding implant survival, although in most cases differences in implant survival between the two groups were not statistically significant. Survival was generally measured as the viability of the dental implant over the course of the observation period. Bone level changes as measured by radiography indicated less bone loss in the periodontitis–negative group in all but one study. Again, most of the differences were not statistically significant. The results of this study indicated that patients with periodontitis had a less successful outcome than patients who did not suffer from dental disease. However, the assessment was limited due to the fact that the study authors determined a number of experimental flaws and biases that made it difficult to interpret the study findings in general. Some of the problems encountered in this retrospective review were inaccurate reporting of data parameters, limited outcome assessment, failure to address confounders such as cigarette smoking and a failure to distinguish accurately between cases of periodontitis that were or were not medically treated. These findings indicated the necessity for additional CRTs to provide more accurate data to assess this important research question. In addition, the authors concluded that periodontitis represents a complicating factor that may affect major parameters of dental implant success, including implant survival and medical complications. Among the more recent research questions involves whether patients with evidence of periodontal disease should have their natural teeth adjacent to the implant replaced also, as implanted material may have a greater longevity than the teeth that are in proximity to this site. The periodontal disease complications may therefore affect long term clinical outcome. Before engaging in prophylactic approaches of this type, it is necessary to review the relevant research in this area. Longitudinal research studies, however, have not addressed this issue and generally use implant failure and survival rates in outcome assessment rather than the overall incidence of tooth loss subsequent to implantation. Thus, currently, there does not appear to be sufficient clinical data to address this question effectively. . References Esposito M, Koukoulopoulou A, Coulthard P, Worthington HV Interventions for replacing missing teeth: dental implants in fresh extraction sockets (immediate, immediate-delayed and delayed implants) (Review) Copyright © 2009 The Cochrane Collaboration. Published by JohnWiley & Sons, Ltd. Karoussis IK, Muller S, Salvi GE, Heitz-Mayfield LJA, Bra¨gger U, Lang NP. Association between periodontal and peri-implant conditions: a 10-year prospective study. Clin. Oral Impl. Res. 15, 2004; 1–7. Ong CTT, Ivanovski S, Needleman IG, Retzepi M, Moles DR, Tonetti MS, Donos N. Systematic review of implant outcomes in treated periodontitis subjects. J Clin Periodontol 2008; 35: 438–462. doi Renouard F, Nisand D. Impact of implant length and diameter on survival rates. Clin. Oral Imp. Res. 17 (Suppl. 2), 2006; 35–51 . Read More