Η επίδραση του περιοδοντικού βιότυπου στη θέση της παρυφής των ελεύθερων ούλων σε δόντια που υπεβλήθησαν σε χειρουργική επιμήκυνση κλινικής μύλης
Creators: name: Μαλαμούδη, Γεωργία Απόστολου
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: χειρουργική επιμήκυνση μύλης
βιότυπος
σταθερότητα αποτελέσματος
surgical crown lengthening
biotype
soft tissue rebound

description: Σκοπός αυτής της προοπτικής μελέτης σειράς περιστατικών είναι να διερευνήσει την επίδραση του βιότυπου στη θέση της παρυφής των ελεύθερων ούλων μετά από χειρουργική επιμήκυνση κλινικής μύλης. Είκοσι έξι ασθενείς που δέχθηκαν χειρουργική επιμήκυνση μύλης, διακρίθηκαν σε δύο ομάδες του λεπτού και του παχύ βιοτύπου με κριτήριο το πάχος των ούλων. Η παρακολούθησή τους πραγματοποιήθηκε με κλινικές, ακτινογραφικές και ανθρωποκεντρικές παραμέτρους και διήρκησε μέχρι και τρεις μήνες μετά την προσθετική αποκατάσταση του δοντιού. Τα αποτελέσματα έδειξαν πως η χειρουργική επιμήκυνση κλινικής μύλης είναι αποτελεσματική στην αποκάλυψη υγιούς οδοντικής ουσίας, ωστόσο το αποτέλεσμα της επέμβασης δεν είναι σταθερό λόγω σταδιακής μυλικής επαναφοράς των μαλακών περιοδοντικών ιστών, η οποία λαμβάνει χώρα κυρίως τις έξι πρώτες μετεγχειρητικές εβδομάδες. Οι μεταβολές που συμβαίνουν στο διάστημα αυτό στην παρυφή των ούλων είναι διαφορετικές μεταξύ των βιοτύπων, με τη μυλική μετατόπιση να είναι μεγαλύτερη για τον παχύ βιότυπο. Η χειρουργική διαδικασία ήταν ανεκτή από τους ασθενείς και η προσθετική αποκατάσταση του θεραπευμένου δοντιού θεωρήθηκε ικανοποιητική τόσο από τους ασθενείς όσο και από τον οδοντίατρο που την πραγματοποίησε
description: The aim of this prospective case series study is to assess the influence of periodontal biotype on gingival margin of teeth that underwent surgical crown lengthening. Thirty-two participants requiring pre-restorative crown lengthening were enrolled in this study and divided into two groups of thick and thin biotype according to their gingival thickness measurement above a maxillary central incisor. Those whose gingival thickness surpassed the threshold of 1 mm were regarded as having thick biotype, otherwise the biotype was considered thin. Clinical parameters were recorded along six surfaces from line angles of treated teeth as well as along the adjacent teeth with adjacent and non-adjacent sites with the aid of an individualized acrylic stent. The following parameters were obtained: relative free gingival margin, probing depth, relative clinical attachment loss, plaque and gingival index. Clinical measurements were repeated preoperatively, post operatively, at six weeks after surgery, at the time of prosthesis delivery and three months after that. Surgical measurements at the above mentioned sites included the distance from stent to alveolar bone both before and after osseous surgery and from stent to flap margin after suturing. Standardized radiographs were also taken with the use of an individualized radiographic stent made of impression material preoperatively, postoperatively, at prosthesis delivery and three months after prosthesis delivery. Interproximal bone level was recorded for treated teeth through digital radiographs while digital subtraction radiography pointed out quality differences between recalls. The Early Wound Healing Index (EHI) was evaluated one and two weeks after surgery. Specially designed questionnaires with VAS scale responses were handed out to the patients, asking them to assess the pain and discomfort they felt during the first days of healing. Also patients were asked to evaluate their satisfaction with regards to the aesthetic and functional result of the final prosthesis. Finally clinicians who performed the prosthetic rehabilitation were asked to express their opinion about the result of the crown lengthening surgery in terms of abutment adequacy. Immediately after surgery the relative gingival margin position was apically displaced by 1,801±0,087 mm at treated, 1,216±0,112 mm at adjacent and 0,319±0,062 at non-adjacent sites. This immediate crown lengthening outcome was however reduced in the long term due to significant soft tissue rebound. Three months after the prosthesis delivery, at treated sites, soft tissue rebound was found to be 0,679±0,087 mm (95%CI: 0,509-0,850) and statistically significant, independent of biotype (p=0,000). Biotype influence on relative gingival margin position was statistically insignificant; however time seems to play a major role in the soft tissue rebound. From post-surgery to six weeks, soft tissue rebound was statistically greater for thick biotype, as compared to thin. Throughout the entire observation time thin biotype presented with an average soft tissue rebound of 0,433±0,140 mm, almost half the value of the rebound for thick biotype (0,833±0,111 mm), however it did not reach statistical significance. For both biotype groups probing depths remained less than 3 mm during the entire study. Three months after prosthesis delivery, average relative attachment loss was 1,367±0,146 mm (95%CI: 0,784-1,23, p=0,000). Relative attachment loss was greater for thin biotype compared to thick with no statistically significant difference between the two groups. The bone resection performed was on average 1,24±0,937 mm at treated sites, without any statistically significant difference among biotypes as well (p=0,595). Plaque and bleeding indexes remained low (PI, BoP≤20%) during the three month observation period, for each site and time interval. Regarding healing, no statistically significant difference was observed between the two groups. Early Wound Healing values ranged between one and three for both groups of biotype. Linear measurements on digital radiographs showed relative stability of the osseous level post-operatively and up to three months from prosthesis delivery. Questionnaire responses revealed positive patient reported outcomes in terms of pain during healing claiming mild, short term discomfort. Patients also perceived the prosthetic outcome as satisfactory. Finally, clinicians reported that the outcome of surgical crown lengthening fulfilled its purpose in terms of crown stability and retention as well as soft tissue retraction without any significant mobility of the treated teeth. Surgical crown lengthening, when indicated, is an effective procedure in gaining sound tooth structure. However, significant soft tissue rebound however takes place during the first three months after the prosthetic rehabilitation of the treated tooth regardless of biotype. This phenomenon is most intense during soft tissue healing, that is six weeks after surgery. During this period soft tissue rebound was found to be significantly different between thick and thin biotype. In total, during the entire observation period, soft tissue rebound for thick biotype was twice the rebound recorded for thin biotype, without reaching statistical significance. Additional prospective clinical trials of similar design but larger samples and longer follow-up, are required in order to obtain more precise clinical directions