Fogorvosi szemle, 2006 (99. évfolyam, 1-6. szám)
2006-12-01 / 6. szám
257 FOGORVOSI SZEMLE ■ 99. évf. 6. sz. 2006. Schlieren, Switzerland; 3Semmelweis University, Budapest / DentalCoop Centre of Stomatology and Operative Dentistry, Budapest, Hungary Introduction: After tooth extraction, the healing of the extraction wound unavoidably goes hand in hand with various rate of resorption of the alveolar bone (1,2). In case of atrophied ridge we can’t achieve functional and aesthetic results supplying all requests neither with conventional fixed prosthesis, nor with implantation (3). In most of the cases satisfactory results can be achieved only after a complex Guided Bone Regeneration procedure (GBR) (3, 4). Prevention of the resorption of the alveolar process is a goal tried to be achieved for a long time, and several solutions have been tried (5). In our execution we present the development and our preliminary experiences of a new alveolar preservation technique [RootReplica® (6, 7, 8)]. Material and methods: In the course of the method we make an impression of the extracted root and we mould the copy of it. The replica is made out of PGLA coated, porous, spherical ß-TCP granules. These are fused together by heating, while it takes the shape of the root. Then we insert the copy into the inflammationfree extraction socket to prevent alveolar loss (8). Results: Regarding our experiences up to now, it can be determined that the system can be applied easily and fast, on the average a replica was ready in ten minutes. According to former researches the full bony remodelling takes 6-12 months in case of ß-tricalciumphosphate (9), in case of the RootReplica® the biomaterial was resorbed completely from the extra-cellular matrix after 60 weeks (8). With this all in view we report the occurrences and our experiences coming up to the day of the presentation. Discussion: The chairside prepared root replica can present several advantages according to the previously used procedures for preserving the alveolar ridge. The tissue dehiscence caused by post-extraction bone remodelling is usually treated with soft tissue and bone augmentation during a second operation. In case of the long lasting success of the presented method, this would mean a change in view as the tissue dehiscence can be omitted with a preventive method, instead of subsequent restoration. This offers a simpler and cheaper choice. Contrary to other alveolar preservation techniques, the macroporous biomaterial allows a blood coagulum to form in its cavities, while its granules stuck close together forms an individually preformed, well adaptable, solid unit. References: 1. Atwood DA, Coy WA: Clinical cephalometric and densitométrie study of reduction of residual ridges. J Prosthet Deni 1971 ; 26: 280-295. 2. Jahangiri L, Delvin H, Ting K, Nishimura I: Current perspectives in residual ridge remodelling and its clinical implications. J Prosthet Dent 1998; 80: 224-237. 3. Buser D, Dula K, Hirt HP, Schenk RK: Lateral ridge augmentation using autographs and barrier membranes: A clinical study with 40 partially edentulous patients. J Oral Maxillofac Surg 1996; 54: 420-432. 4. Esposito M, Grusovin MG, Worthington HV, Coulthard P: Interventions for replacing missing teeth: bone augmentation techniques for dental implant treatment. Cochrane Database Syst Rev 2006 Jan 25;(1): CD 003607. 5. Schmidlin PR, Jung RE, Schug J: Prevention of alveolar ridge resorption after tooth extraction - a review. Schweitz Monatsschr Zahnmed2004:114(4): 328-336. 6. Suhonen JT, Meyer BJA: Polylactic acid (PLA) root replica in ridge maintenance after loss of vertically fractured incisor. Endod Dent Traumatol 1996; 12: 155- 160. 7. Nair Pn PR, Schug J: Observations on healing of human tooth extraction sockets implanted with bioabsorbable polylactic-polyglycolic acids (PLGA) copolymer root replicas: a clinical, radiographic, and histologic follow-up report of 8 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004; 97(5): 559-569. 8. Nair PN, Luder HU, Maspero FA, Fischer JH, Schug J: Biocompatibility of Beta-tricalcium phosphate root replicas in porcine tooth extraction sockets - a correlative histological, ultrastructural, and x-ray microanalytical pilot study. J Biomater Appl 2006; 20(4): 307-324. Epub 2006 Jan 27. 9. Palti A, Hoch T: A concept for the treatment of various dental bone defects. Implant Dent 2002; 11(1): 73-78. RADIOLOGICAL EXAMINATION OF BONE MUTATION BY TEETH AND IMPLANTS SUPPORTED FIXED BRIDGES SZÖLLŐSI, K. Private dental practitioner, Budapest, Hungary Introduction: Application of Ankylos implants were launched in 1998 in Budapest. In the first three years a lot of fixed partial dentures were inserted connecting natural teeth and implants. All of the implants were two-phase implants with a healing period of 3-6 months. Recently less bridgeworks with mixed support are used according to the international standards: only missing teeth in the arch are replaced by implants if possible - leaving natural teeth untouched. According to the numerous earlier treated cases we considered comparing the radiological findings at the time of the implant insertion and the 5 years control radiographs and analyzing the changes of the bone around the different abutments that occurred during function. Methods: Examinations were carried out on digitalized panoramic X-rays: vertical and horizontal bone-changes were measured at the abutments. The number of