Evaluation of static fracture resistances and patterns of pulpless tooth restored with poly-ether-ketone-ketone (PEKK) post / 대한치과보철학회지

PURPOSE: The purpose of present study was to investigate fracture strength and mode of failure of endodontically treated teeth restored with metal cast post-core system, prefabricated fiber post system, and newly introduced polyetherketoneketone (PEKK) post-core system. MATERIALS AND METHODS: A total of 21 mandibular premolar were randomly grouped into 3 groups of 7 each according to the post material. Group A was for metal cast post core; Group B for prefabricated glass fiber post and resin core; and Group C for milled PEKK post cores. All specimens were restored with metal crown. The fracture strength of each specimen was measured by applying a static load of 135-degree to the tooth at 2 mm/min crosshead speed using a universal testing machine. After the fracture strength measurement, the mode of failure was observed. The results were analyzed using Kruscal-Wallis test and post hoc Mann-Whitney U test at confidence interval α = .05. RESULTS: Fracture resistance of PEKK post core was lower than those of cast metal post and fiber reinforced post with composite resin core. In the aspect of fracture mode most of the root fracture occurred in the metal post core, whereas the post detachment occurred mainly in the fiber reinforced post. In the case of PEKK post core, teeth and post were fractured together. CONCLUSION: It is necessary to select appropriate materials of post for extensively damaged teeth restoration and clinical application of the PEKK post seems to require more research on improvement of strength.

Effect of surface pre-treatments and adhesive types on the shear bond strength between PEKK and Zirconia / 대한치과재료학회지

In this study, the effects of surface pre-treatment and adhesive type on the shear bond strength between PEKK (polyetherketoneketone) and zirconia were analyzed by means of shear bond test and fracture aspect analysis. RI group (sand blasted with 110 µm Rocatec + silane primer applied + Premier implant cement) showed the highest shear bond strength value (9.01 MPa), followed by AI (7.94 MPa), NI (5.62 MPa), RT (2.71 MPa), AT (2.25 MPa), and NT (non-treated + Hy-bond, 1.96 MPa) groups showed the lowest values. Analysis of shear bond strength according to the type of cement showed that the group using resin cement for implant was higher than the group bonded with polycarboxylate cement regardless of the surface treatment (p < 0.05). As a result of analysis of shear bond strength according to the surface treatment, the silane primer applied to the surface of 110 µm particle size Rocatec showed the highest value (p < 0.05). The fracture patterns of the specimens were analyzed by surface treatment and cement type. Polycarboxylate cement showed better bond strength with zirconia specimen and resin cement showed higher bond strength with PEKK specimen.

Effect of non-thermal plasma on the shear bond strength of resin cements to Polyetherketoneketone (PEKK)

PURPOSE: This study aimed to assess the effect of non-thermal plasma on the shear bond strength of resin cements to polyetherketoneketone (PEKK) in comparison to other surface treatment methods. MATERIALS AND METHODS: Eighty PEKK discs were subjected to different surface treatments: (1) Untreated (UT); (2) Non-thermal plasma (NTP); (3) Sandblasting with 50 µm Al2O3 particles (SB); and (4) Sandblasting + Non-thermal plasma (SB+NTP). After each surface treatment, the contact angle was measured. Surface conditioning with Visio.Link was applied in all groups after pre-treatment. RelyX Unicem resin cement was bonded onto the PEKK specimens. After fabrication of the specimens, half of each group (n=10) was initially tested, while the other half was subjected to thermocycling (5℃ to 55℃ at 10,000 cycles). Shear bond strength (SBS) testing was performed using a universal testing machine, and failure modes were assessed using stereomicroscopy. The SBS results were analyzed statistically using one-way ANOVA followed by Tukey's post hoc test. Independent t-test was used to examine the effect of thermocycling (P < .05). RESULTS: The highest SBS values with or without thermocycling were observed with PEKK specimens that were treated with SB+NTP followed by the SB group. The lowest SBS results were observed in the UT groups. CONCLUSION: The shear bond strength between PEKK and resin cements was improved using non-thermal plasma treatment in combination with sandblasting.

Shear bond strength of composite resin to high performance polymer PEKK according to surface treatments and bonding materials

PURPOSE: The object of the present study was to evaluate the shear bonding strength of composite to PEKK by applying several methods of surface treatment associated with various bonding materials. MATERIALS AND METHODS: One hundred and fifty PEKK specimens were assigned randomly to fifteen groups (n = 10) with the combination of three different surface treatments (95% sulfuric acid etching, airborne abrasion with 50 µm alumina, and airborne abrasion with 110 µm silica-coating alumina) and five different bonding materials (Luxatemp Glaze & Bond, Visio.link, All-Bond Universal, Single Bond Universal, and Monobond Plus with Heliobond). After surface treatment, surface roughness and contact angles were examined. Topography modifications after surface treatment were assessed with scanning electron microscopy. Resin composite was mounted on each specimen and then subjected to shear bond strength (SBS) test. SBS data were analyzed statistically using two-way ANOVA, and post-hoc Tukey's test (P<.05). RESULTS: Regardless of bonding materials, mechanical surface treatment groups yielded significantly higher shear bonding strength values than chemical surface treatment groups. Unlike other adhesives, MDP and silane containing self-etching universal adhesive (Single Bond Universal) showed an effective shear bonding strength regardless of surface treatment method. CONCLUSION: Mechanical surface treatment behaves better in terms of PEKK bonding. In addition, self-etching universal adhesive (Single Bond Universal) can be an alternative bonding material to PEKK irrespective of surface treatment method.

Maxillar implant-retained overdenture using CAD/CAM milled zirconia bar with PEKK sleeve: a case report

The object of this case report is to introduce milled zirconia bar and PEKK female part made by CAD/CAM technology for bar attachment implant supported overdenture in maxillary edentulous patients. For over 2 years, in terms of function and esthetics, satisfactory result was obtained. Esthetically and functionally satisfactory results were obtained in periodic follow up check.