implant - supported overdenture prostheses can be divided into bar overdentures and single attachment overdentures .
single attachment elements for overdentures include single retentive anchors , single magnet anchors , and individually cast telescopic copings.1 among these , telescopic copings have the benefit of implant splinting found in bar overdentures and the retrievability of single attachment overdentures
. however , this method is typically fabricated using gold materials , so it is not an economical treatment option .
also , if an inner crown will be worn , it is difficult to maintain appropriate retentive forces . in this case report
, a telescopic implant - supported overdenture prosthesis was made using a new material , polyaryletherketone ( paek ) based polymer ( pekkton ivory , cendres + mtaux sa , biel / bienne , switzerland ) .
it shares benefits of typical telescopic coping , in additional to being highly economical , wear resistant , and light in weight compared to conventional implant overdenture prostheses .
1 ) presented to the department of prosthodontics at chonnam national university dental hospital . after clinical and radiographic examinations
after maxillary teeth extractions and use of provisional maxillary complete denture for six months , six small diameter implant fixtures ( 3.0  10.0 mm usii , osstem implant co. ltd . , seoul , korea )
the definitive prosthesis was planned as a telescopic overdenture using paek based polymer . after a making definitive impression by polyvinylsiloxane ( honigum , dmg , hamburg , germany ) , a polymer telescopic abutment and an outer overdenture frame were fabricated with consideration of the patient 's vertical dimension ( fig .
telescopic abutment and framework design were laid out by cad software ( exocad dental cad , exocad gmbh , darmstadt , germany ) . the milling machine
( s1 , vhf camfacture ag , ammerbuch , germany ) made the final framework and abutment according to the design .
polymer abutment and titanium link were sandblasted by 110 um grit aluminum oxide , and bonded with primer ( sr link , ivoclar vivadent , schaan , liechtenstein ) and bonding agent ( multilink n , ivoclar vivadent , schaan , leichtenstein ) .
after that , the definitive prosthesis was made by autopolymerized pour - type resin ( press lt , retec , rosbach , germany ) ( fig .
4 ) ; the design and weight of the prosthesis were adjusted to achieve acceptable esthetics and phonetics . after 6 months , there were no problems with alveolar bone around the implant fixtures and retention of the overdenture prosthesis .
however , no treatment modality meets all criteria for successful treatment , and conventional overdenture material can sometimes be limited by economic , functional , and technical considerations .
now , many new prosthetic materials are available to overcome these limitations , and as in this case , a new polymer can be used to make telescopic crowns and frameworks to obtain satisfactory results .
paek based polymer , pekkton ivory , as used in this case , is a member of the high performance semi - crystalline thermoplastic resin group , recognized for its keto and ether group ratio .
paek has good dimensional stability at high temperature , high chemical and mechanical resistance against wear , and high tensile , fatigue and flexural strength , making it an attractive material with expanded uses in medicine and dentistry.3 however , peek ( polyetheretherketone ) , a conventional paek - based polymer , can not be used as a permanent material due to its relatively weak physical properties . a new material , pekkton , is mainly composed of pekk ( polyetherketoneketone ) ; its molecular structure has an added ketone to the structure of peek with and has a wide range of uses due to its amorphous and crystalline structure .
pekk reveals up to 80% greater compressive strengths than peek , so this polymer may be used in permanent prostheses according to the manufacturer.4 thus , this new polymer can be considered to have greater strength than peek and have greater esthetics titanium , higher resin bond strength than zirconia , and a lighter weight ( 1.4 g / cm ) than metal .
therefore , this material is found to be mechanically suitable for fpd frameworks , milled overdenture bars , clasps , telescopic crowns , and other applications . despite the reportedly good bond strength ,
bonding between the titanium link and the telescopic abutment is still very sensitive , with the risk of fracture of the thin abutment wall due to connecting titanium link ; hence more studies are needed on such cases .
she reported satisfaction with its strength and esthetics , and no negative symptoms . due to the lack of evidence on the long term retentive capabilities of this material ,
due to its functional and economic advantages , paek based polymer is a good alternative material to conventional materials and methods in the fabrication of implant overdenture .
 although many prosthetic materials exist for fabrication of implant - supported telescopic overdentures , available materials have not been thoroughly evaluated from a functional standpoint . 
 this case report describes the use of polyaryletherketone ( paek ) based polymer for an implant - supported telescopic overdenture , a seldom used material in dentistry . this material is lighter than traditional materials , 
 can accommodate changes in retentive forces , and is an easily retrievable by cad / cam fabrication . 
 this case highlights the possibility of using new polymer materials for implant - supported telescopic overdentures . 