Radiographic Analysis Of Peri-implant Marginal Bone Level Change And Soft Tissue Change Around Implant

Background: The lack of teeth is a common and frequently-occurring oral diseases. With the development of oral planting implant technology, implant restoration has become one of conventional method to repair teeth missing. As continuously improve of the implant structure, the surface, operation and repair methods, the indications of implant expanded, time of treatment shortened, function and esthetics effect improved. First proposed by Branemark in April 1992,osseointegration theory is the pivotal foundation of oral implant, refers to the direct contact between the implant and the living bone in the light microscope. The extent of bone combination can be strengthened over time. In molecular level, the bone closely stick to implant surface. Animal experiments shows that implant body and alveolar bone may establish direct bone anchor .The destruction of implant - bone interface tissue always begin from ridge top. The factors of bone absorption are multiplicity, such as surgical trauma, the change of blood supply around implant, microorganism and their products, the materials of implant, and the infection between the crevice of implant and base station, etc. The absorption of bone surrounding implant is one of important standards to evaluate the success of oral implant and denture repair, considered sensitive tool to estimate implant clinical effect. Since the gradually absorption of bone aroud implant will lead to the loss of bone support, and may finally cause the failure of implant surgery.Periodontitis is one of the risk factors of implant. For the past few years,sesearch has reported that periodontitis patients may gain the aequales achievement ratio of implant. Oppositely, some scholars discovered that periodontitis patients obtain lower persistence than healthy patients. The present studay contains 11 periodontitis patients of 23 implants contained in this experiment,compared to the healthy patients to the healthy patients.Radiographic examination can provide shape, structure, bone density and other important information, in addition to be used to formulate treatment planning in implant healing process, still can be used for evaluating the therapeutic efficacy of implant after operationNowadays,panoramic and periapical film are the necessary mean-s to the design and estimatione of dental implant. However,other rep-orts discovered that panoramic with momentous practical value could replace periapical film to evaluate the marginal bone around implat, and The contrasting consequence of clinical practice shows that the effectiveness of periapical film is more accurate and distinct. Our experiment uses panoramic to observe the marginal bone around peri- implant.The success criteria of implant include three aspects: stability, functional and aesthetic effect. Successful implant denture should not only restore the lack of tooth district organization and function, but also to recover the form of soft tissue, making it coordinated with adjacent teeth, achieving esthetics and natural effect. The aesthetic and soft tissue aesthetics of implanting restoration is a new hotspot. PES rating system (Pictorial view of pink esthetic) is a new tools to estimate the soft tissue aesthetic outcome around implant compared to normal teeth , comprehensive referencing the color, texture, height, form of the soft tissue around implant, using comprehensive seven variable and 3 points for evaluation, is a relatively complete system.At present, there are a number of researchs correlating to the radiographic analysis of peri-implant marginal bone level change. And the bulk of domestic and foreign scholars applys questionnaire for evaluating aesthetic effect of soft tissue around implant, and assess of the soft tissue around implant effect of a few reports. This study adopts implant patients in department of stomatology of Coal General Hospital, measuring and analyzing the imaging data in the healing process and after implant repairing, observing the changes of peri-implant marginal bone level. And comparation of the periodontitis patients and healthy patients ,to observe the difference between the both. Observing and recording repair the condition of tissue around after implant denture with PES scoring system stateObjective: Using radiographic method to analysis the peri-implant marginal Bone level change and soft tissue change around implant, as well as comparing the difference of periodontitis and healthy. And using Pictorial view of pink esthetic score variables to evaluat soft tissue aesthetic.Methods: All the implant patients were from the department of stomatology of Coal General Hospita from April 2009 to April 2011,including 42 patients with 71 implants , combined with complete clinical data, that has already repaired over 12 months. Observe the panoramic of that day of implants planted , the first 4 months (mandible) or 6 months (maxilla) after implant planted,3 and 6 and 12 months after restoration,measuring and analyzing the change of the peri-implant marginal bone,and comparing periodontitis patients and healthy patients to find the difference. Using PES scoring system to estimate the soft tissue after implant repairedResults: 1. There is about 0.25 mm shadow between the screw of implant and surface of alveolar bone shown on the panoramic. After loading, the shadow has vanished .2. there is a scallops bone resorption around the implant in the first month after surgery. The second month after surgery, the density of the scallops bone resorption around implant increased to some extent,but still distinct. After loading, the density of the scallops bone resorption around implant improved obviously3. The average of the marginal bone resorption in every period: 0.66 mm for 1month after implant planted, 0.78 mm for 4-6 monthes after implant planted(P > 0.05). 1.06 mm after loading 1 month, 0.63mm after loading 3 months, 0.55 mm after loading 6 months, 0.58 mm after loading 12 months. There is statistically significant between the level of the first month and thoes of other three timelines.(P<0.05)4. The difference of the marginal bone resorption between the periodontitis and the healthy has not statistically significance.5. The PES score of 4 periods after the implant fixed restoration: the average score is 8.72 after first month , 10.31 after 3 months fixed restoration, 11.10 after 6 months fixed restoration, 12.71 after 12 months fixed restoration, difference between each other has statistical significance(P<0.05).Conclusion:1. All of the implant has obtained satisfactory osseointegration.2.The marginal bone resorption around the unloaded implants mainly takes place in the first month after operation.3.The majority of the marginal bone resorption around the loaded implants takes place in the first month after the implant restored. The height of the marginal bone could be to increase significantly after load 3 months. 4. The short-time outcomes of implant restoration in chronic periodontitis patient were good only if the inflammation were well controlled.5. The score of the PES increased over time after the implant repaired.