10 year Clinical Observation of Dyna Magnetic Precision Attachments Case Report

CLINICAL CASE Dent. Med. Probl. 2007, 44, 1, 87 91 ISSN 1644 387X Copyright by Silesian Piasts University of Medicine in Wrocław and Polish Stomatological Association SŁAWOMIR MAKACEWICZ, HALINA PANEK 10 year Clinical Observation of Dyna Magnetic Precision Attachments Case Report 10 letnie obserwacje kliniczne zaczepów magnetycznych Dyna opis przypadku Department of Prosthodontics, Silesian Piasts University of Medicine in Wrocław, Poland Abstract In the paper, the authors present a clinical evaluation of magnetic precision attachments Dyna used for retaining the partial overdentures. During 10 year observations performed in one of the first treated patients, the authors revealed that Dyna attachments showed high technical quality without any damage or need for their replacement. Moreover, the authors observed minimal harmful influence of the magnet attachments on periodontium of abut ment teeth in comparison to that associated with the use of conventional mechanical attachments in such long peri od of wearing (Dent. Med. Probl. 2007, 44, 1, 87 91). Key words: magnetic precision attachments, clinical evaluation. Streszczenie W pracy autorzy przedstawili wyniki klinicznej oceny zaczepów magnetycznych Dyna stosowanych do retencji protez pokrywających typu overdentures. Na podstawie 10 letniej obserwacji jednej z pierwszych pacjentek leczo nych protetycznie z zastosowaniem zaczepów Dyna autorzy stwierdzili, że zaczepy te wykazują się wysokim stop niem niezawodności technicznej, która wyrażała się brakiem konieczności ich naprawy lub wymiany. Długoletnie stosowanie zaczepów magnetycznych Dyna wywołuje minimalny wpływ uszkadzający w obrębie aparatu zawie szeniowego zębów filarowych w porównaniu ze stwierdzanym w obecności konwencjonalnych zaczepów mecha nicznych (Dent. Med. Probl. 2007, 44, 1, 87 91). Słowa kluczowe: zaczepy protetyczne magnetyczne, obserwacje kliniczne. First trials to use magnets for the purpose of enhancing retention of removable dentures con sisted in their implantation in the bone. Such a pro cedure was dictated by necessity to use large mag nets due to inadequate attractive force of early magnetic materials. They were mainly based on Al Ni Co, and next Co Pl alloys. However, the implanted magnets were observed to migrate with in the bone until their complete exposure in the oral cavity [1, 2]. In late 60s of the last century, trials were made to use magnets containing alloys of rare earth ele ments, such as neodymium iron boron (Nd Fe B), as well as samarium and cobalt (Sm Co). The materials revealed stronger magnetic potentials, which enabled reduction of the size of the attach ments to be inserted into the dental roots [2 8]. The most recommended attachment systems man ufactured from rare earth metals include: Dyna (Dyna Dental Engineering, Bergen, Netherlands), Steco (Steco System Technik, GmbH & Co, Hamburg, Germany). Dyna magnetic attachments were first used in the Department of Prosthodontics, Medical University in Wrocław in 1996 [8]. They are most commonly used for retaining overdentures which were performed in patients with residual or reduced dentition often in connection with peri odontal disease and unfavourable prognosis con cerning the abutment teeth. In such cases, conven tional mechanical attachments may, in a short time, lead to loosening of the abutment teeth due to improperly applied tangent forces in relation to the efficiency of the tooth support system [6,

88 S. MAKACEWICZ, H. PANEK 9 10]. For this reason, a procedure of shortening of the anatomical crown was performed in the abutment teeth with unfavourable proportion of the supra alveolar portion in relation to the portion embedded in the bone of the alveolar process. Thus, a more favourable proportion of the tooth parts was obtained and next Dyna intraradical attachments were attached to them. In 2006, first two patients obtained 10 year follow up period of using overdentures retained by means of magnetic attachments. They constitute 5% of all the patients treated with this method in years 1996 1998. The applied magnets had retention force of 300 G. In years 1999 2002, 500 G magnets were introduced to various kinds of overdentures. The aim of the paper was to present clinical evaluation of Dyna magnetic attachments after 10 year follow up in one of the first patients treated at the Department of Prosthodontics in Wrocław [11]. Such a long survival of magnetic attachments in the oral cavity has not been described in Polish literature so far. Fig. 2. Intraoral view after cementation of dowels and cores with caps Ryc. 2. Zdjęcie wewnątrzustne pacjenta po zacemen towaniu wkładów korzeniowych z kopułą koronową Case Report First Dyna attachments were used at our Clinic in 1996 in a 40 year old patient E.K., Case Record No. 599/96, who was seen for prosthetic treatment due to partial loss of dentition. The clinical exam ination revealed class II loss of teeth in the maxil la and class IV in the mandible according to Galasińska Landsbergerowa [12]. Moreover, the patient revealed a generalized periodontopathy manifested by I pathological mobility of teeth according to Entin of 13, 11, 21, 23, 33, 32, 31, 41, 42 and 43 teeth and grade III mobility of 18, 17, 15, 14, 24, 27, 28, 35, 34 and 47 teeth [12]. Analysis of radiological pictures of the teeth revealed extensive loss of bone of the alveolar process in the maxilla and the mandible (Fig. 1). The following treatment plan was established: Fig. 3. Magnet attachments Dyna before installation in partial lower overdenture Ryc. 3. Zaczepy magnetyczne Dyna przed zamonto waniem w dolnej protezie pokrywającej Fig. 4. The lower partial overdenture with magnet at tachments in 1996 Ryc. 4. Dolna proteza częściowa pokrywająca z zacze pami magnetycznymi w 1996 r. Fig. 1. The panoramic radiogram of patient dentition before treatment in 1996 Ryc. 1. Panoramiczne zdjęcie rentgenowskie uzębienia pacjenta przed leczeniem w 1996 r. 1) extraction of all the teeth with grade III mobility; 2) endodontic treatment of the remaining four upper teeth and lower canines and next their shortening to the level of about 2 mm above the free gingival margin; 3) performance of root dowels with caps for the teeth after endodontic treatment as abutment elements for a full overdenture in the maxilla and partial overdenture in the mandible (Fig. 2). Dyna magnetic attachments were selected as a method of retention of the lower denture, due

Dyna Magnetic Precision Attachments 89 Fig. 5. The panoramic radiogram of dentition in 2002 Ryc. 5. Panoramiczne zdjęcie rentgenowskie uzębienia w 2002 r. Fig. 6. X ray of tooth 43 in 2003 Ryc. 6. Zdjęcie rentgenowskie zęba 43 w 2003 r. Fig. 7. X ray of tooth 33 in 2003 Ryc. 7. Zdjęcie rentgenowskie zęba 33 w 2003 r. Fig. 8. The panoramic radiograph of the patient denti tion in 2006 Ryc. 8. Panoramiczne zdjęcie rentgenowskie uzębienia pacjenta w 2006 r. to unfavourable biological factor (Figs. 3 4). On completion of the active phase of prosthetic treatment, the patient was advised as to the hygienic measures of the dentures and the oral cavity and she was recommended to come for follow-up visits every year. The control examination carried out one year after the termination of prosthetic treatment revealed maintenance of good functional and esthetic effects. No significant changes were observed within the muco osseous foundation and in the periodontal region of the abutment teeth. The examination did not reveal a decreased reten tion of the lower denture on Dyna attachments. Subsequent follow up examination two years after termination of the prosthetic treatment revealed inflammatory condition in the periodon tium as well as gingival recession on the vestibu lar surfaces in the region of incisors and abutment teeth covered with metal cups. Bacterial plaque was found on all the maintained teeth pointing to insufficient oral hygiene. The dentures, magnets and their clasps were evaluated positively. Capsules of the magnet were not worn out, and the acrylic material was not discoloured in their region. Retention attachment of the lower denture on Dyna attachments did not reveal any changes in relation to the initial condition. The patient was satisfied with the ability of normal phonation, sta bilization and esthetics of the denture, which was very important in her teaching profession. The patient came for the next follow up six years after termination of the prosthodontic treat ment, i.e. in January 2002. The visit was caused by detachment of the magnet s clasp from the root of tooth 43. Clinical examination revealed II mobility according to Entin of the following teeth: 13, 23, 31 and 42 as well as significant hygienic negligence of the oral cavity and the denture. Radiological panoramic examination of the whole dentition revealed progressive atrophy of the alveolar bone, especially evident in the maxilla (Fig. 5). The patient was instructed as to the necessity of maintaining proper oral and denture hygiene. Rinsing mouth with 0.2% chlorhexidine was recommended. Moreover, the patient was reminded about the necessity of follow-up examinations every year. The next follow up examination was per formed in Fabruary 2003, i.e. 7 years after comple tion of prosthodontic treatment. Clinical examina tion did not reveal any significant changes in rela tion to the condition in the year 2002. Panoramic X ray picture of the whole dentition as well as X ray pictures of adjoining teeth 33 and 34 were per formed. The radiological examination did not show any periapical changes in the abutment teeth 33 and 43 (Figs. 6 and 7), which were burdened with mag

90 S. MAKACEWICZ, H. PANEK netic clasps, only widening of the gingival crevice in the coronal part of the root was demonstrated, what might have resulted from many years load to the abutment teeth and their overloading due to progressive settling of the lower denture on distal portions of the alveolar process. Dyna magnetic attachments did not show any traces of corrosion nor decreased retention force. On the last follow up examination in 2006, the panoramic X ray picture of the whole dentition was made (Fig. 8). This examination did not reveal any significant changes in the abutment teeth in comparison to the earlier made X ray pictures. The patient was advised to line her lower denture with acrylic resin due to some settling of the denture on the alveolar ridge, but she refused to do so. Generally, she was very glad with the function and esthetics of her dentures. Discussion Survival time of rare earth metals magnetic attachments is conditioned by numerous factors, but corrosion of the metals in the environment of the oral cavity is the main problem. Sm Co and Nd Fe B proved especially susceptible to corro sion, while Pd Co Pt revealed a little more resis tance to it. Moreover, in vitro investigations have shown that the products of rare earth magnets cor rosion reveal a cytostatic effect [13]. In order to protect magnetic materials from the effects of flu ids in the oral cavity, they were initially covered with a thin layer of polytetrafluoroethylene (PTFE) or burnt graphite. However, the above pro tective materials proved inadequate for a pro longed use in the oral cavity as they do not offer sufficient imperviousness of the magnetic alloy and in consequence enable its corrosion [14]. Currently some of the manufactured magnetic clasps are enclosed in stainless steel or titanium capsules. One of the trials indicated that protective capsules made of stainless steel were undergoing point corrosion and complete damage 18 months after insertion into the oral cavity [10]. In such cases, loss of retention of the prosthesis is observed, and accumulation of corrosive points may cause discoloration of the artificial teeth. On the other hand, polymer materials seals were asso ciated with fluid and ions diffusing under the pro tective film and attacking components of the mag net [13, 14]. Recently, new magnet sealing meth ods have been applied, such as laser sealing in Dyna system. However, as stated by Jackson [1], their clinical usefulness requires further investiga tions. Our observations [8, 11, 15 16] prove that Dyna attachments may survive in the oral cavity as long as 10 years even at significant hygienic neglect of the dentures and oral hygiene and also despite significant load associated with their use in the condition of extensive teeth loss. The authors conclude that Dyna magnetic attachments are characterized by high level of technical quality. Comparative radiological evalu ation ot teeth with inserted magnetic coils revealed lack of a negative effect of the magnetic material on their efficiency. Dyna magnetic attachments are characterized by high reliability, minimization of turning effort acting on abutment teeth, simple clinical and laboratory procedure and they are easy to use by the patients. References [1] JACKSON T.R., HEALEY K.W.: Rare earth magnetic attachments: the state of the art in removable prosthodontics. Quintes. Int. 1987, 18, 41 51. [2] JONKMAN R.E., VAN WAAS M.A., KALK W.: Satisfaction with complete intermediate dentures and complete inter mediate overdentures. A 1 year study. J. Oral. Rehabil. 1995, 22, 791 796. [3] KOKUBO Y., FUKUSHIMA S.: Magnetic attachments for esthetic management of an overdenture. J. Prosthet. Dent. 2002, 88, 354 355. [4] KRYSIŃSKI Z.: Magnesy jako elementy retencyjne protez stomatologicznych. Pozn. Stomat. 1992, 20, 141 146. [5] STENDERA P.: Zastosowanie magnesów w protetyce stomatologicznej część I: Przegląd piśmiennictwa. Prot. Stomat. 1996, 46, 160 165. [6] STENDERA P., SPIECHOWICZ E.: Analiza wczesnych niepowodzeń w leczeniu protetycznym z użyciem uzupełnień typu overdenture. Prot. Stomat. 1998, 48, 313 318. [7] WATANDABE I., TANAKA Y., OHKUBA C., MILLER A.W.: Application of cast magnetic attachments to sectional com plete dentures for a patient with microstomia: A clinical report. J. Prosthet. Dent. 2002, 88, 573 577. [8] MAKACEWICZ S., PŁONKA B.: Umocowanie dolnej protezy pokrywającej na zaczepach magnetycznych. Opis przy padku. Wroc. Stomat. 1997, 69 73. [9] KUBIAK W., GRODECKI P.: Niektóre elementy precyzyjne stosowane w protetyce stomatologicznej przegląd piśmiennictwa część I. Prot. Stomat. 1998, 48, 11 18. [10] RILEY M.A., WALMSLEY A.D., HARRIS I.R.: Magnets in prosthetic dentistry. J. Prosthet. Dent. 2001, 86, 137 142. [11] MAKACEWICZ S., KRAWCZYKOWSKA H., PŁONKA B.: Zastosowanie magnesów metali ziem rzadkich do utrzymania ruchomych protez częściowych. Prot. Stomat. 1997, 47, 298 300. [12] SPIECHOWICZ E.: Protetyka stomatologiczna. PZWL, Warszawa 2004.

Dyna Magnetic Precision Attachments 91 [13] WIRZ I.: Magnetanker in Korrosiontest. Quintes. Int. 1990, 5, 879 886 [14] WILSON M., KPENDEMA H., NOAR J.H., HNT N.P., MORDAN N.J.: Corrosion of intraoral magnets by multi species biofilms in the presence and absence of sucrose. Biomaterials 1997, 18, 53 57. [15] KRAWCZYKOWSKA H., PŁONKA B., MAKACEWICZ S.: Możliwości zastosowania zaczepów protetycznych w pro tezach pokrywających. Prot. Stomat. 1997, 47, 25 28. [16] MAKACEWICZ S., BOHATER P.: Zastosowanie zaczepu magnetycznego do utrzymania dolnej protezy częściowej pokrywającej opis przypadku. Wroc. Stom. 1998, 99, 105 107. Address for correspondence: Sławomir Makacewicz Department of Prosthodontics Silesian Piasts University of Medicine Krakowska 26 50 425 Wrocław Poland Tel.: +48 71 784 02 90 E mail: panek@prostom.am.wroc.pl Received: 16.01.2007 Revised: 1.02.2007 Accepted: 5.02.2007 Praca wpłynęła do Redakcji: 16.01.2007 r. Po recenzji: 1.02.2007 r. Zaakceptowano do druku: 5.02.2007 r.