Metal-Ceramic and Polyether Ether Ketone–Composite Maxillary Fixed Prosthesis Supported by Four Implants and Opposed by Removable Distal Extension Partial Dentures: A Comparative Study of Clinical and Prosthetic Outcomes

Clinical, Radiographic, and Prosthetic Outcomes of Poly Ether Ether Ketone (PEEK) Versus Poly Ether Ketone Ketone (PEKK) Frameworks in Mandibular Fixed-Detachable Implant-Supported Prosthesis: A Randomized Clinical Trial

“…The implant success and the prosthetic survival rates in the PEEK and PEKK groups were (100%) after one year follow-up. These findings are comparable to other studies' findings 22,46,61 comparing the PEEK to the metal frameworks in fixed-detachable prostheses. These high rates can be attributed to the strict patient selection criteria, appropriate cases diagnosis, forethought treatment plan, meticulous surgical procedures, proper choice of implant system with advanced doublegrip surface enhancing osseointegration, delayed loading of the implants after ensuring successful osseointegration, properly designed and precisely constructed prostheses.…”

“…According to a systematic review, parafunctional habits represent extreme overload on the prosthesis and are considered a crucial reason for prosthetic fracture and failure 74 . The low incidence of prosthetic complications with high performance polymers was reported in other studies 22,46,32 . The higher incidence of prosthetic complications especially abutment screw loosening in the PEEK group compared to the PEKK group may be attributed to the lower elastic modulus of the PEEK compared to PEKK which increases the stresses on the screws 75 .…”

“…The relatively increased plaque accumulation in the PEEK group compared to the PEKK group may have triggered the elevated sGI and mSBI values owing to gingival inflammation and irritation. This relationship between plaque accumulation and gingival inflammation was documented 22,46 . Hence, the results of the sGI and mSBI followed the same pattern as that of the mPI in both groups.…”

“…Accordingly, the successful clinical performance of the PEEK and PEKK as framework materials in implant supported prostheses individually is reported in the current study. This higher success was documented in limited clinical studies 32,22,[40][41][42][43][44][45][46][47][48][49][50] and scarce invitro studies that compared the PEEK to PEKK 12,26,35 . The superior biomechanical properties of both materials encouraged their use in implant screw retained prosthesis.…”

“…Besides, these studies were few; most were case reports, and randomized clinical trials were more scarce. Almost all these randomized clinical trials compared metal alloys to PEEK as a framework material [40][41][42][43][44][45][46] . Despite the versatility in manufacturing PEKK and its rising popularity, rare studies explored the clinical performance of PEKK and most of them were case reports 32,[47][48][49][50] .…”