STATEMENT OF PROBLEM Polyetheretherketone (PEEK) can be used as a framework material for fixed dental prostheses. However, information about the durable bond to veneering resins is still scarce. PURPOSE The purpose of this study was to investigate the effect of chemical treatments of PEEK on tensile bond strength (TBS) to veneering resins with special emphasis on surface free energy (SFE) and surface roughness (SR). MATERIAL AND METHODS Seven-hundred fifty PEEK specimens were fabricated and divided into the following 3 pretreatment groups (n=250/group): etching with sulfuric acid for 60 seconds, etching with piranha acid for 30 seconds, and an unetched control. After pretreatment, SFE was determined by using contact angle measurements and SR with a profilometer (n=10/group). The topography of pretreated PEEK surfaces was examined with scanning electron microscopy. Remaining specimens (n=240 per group) were conditioned with visio.link or Signum PEEK Bond, or were left untreated as the control group. Half of each group was veneered with Sinfony or VITA VM LC (n=40/group), and TBS was measured after storage in distilled water at 37°C for either 24 hours or 60 days. Data were analyzed by 4-way and 1-way ANOVA followed by the Scheffé post hoc test and chi-square test (=.05). RESULTS PEEK specimens etched with sulfuric acid resulted in higher SFE and SR than specimens without pretreatment or etching with piranha acid. Etching with sulfuric acid or piranha acid led to no general recommendations with respect to TBS. Conditioning with visio.link or Signum PEEK Bond significantly increased the TBS (P<.001). PEEK veneered with Sinfony showed significantly higher TBS values than those veneered with VITA VM LC (P<.001). CONCLUSIONS Sufficient TBS for bonding to veneering resin can only be achieved when additional adhesive materials were applied. ABSTRACTStatement of the problem. Polyetheretherketone (PEEK) can be used to support fixed dental prostheses (FDPs). However, information about the durable bond to veneering resins is still scarce.Purpose. The purpose of this study was to investigate the effect of chemical treatments of PEEK on tensile bond strength (TBS) to veneering resins with special emphasis on surface free energy (SFE) and surface roughness (SR). Materials and methods.Seven-hundred-fifty PEEK specimens were fabricated and divided into the following 3 pretreatment groups (n=250/group): etching with sulfuric acid for 60 seconds, piranha acid for 30 seconds, and an unetched control. After pretreatment, SFE was determined by using contact angle measurements and SR with a profilometer (n=10/group).

This clinical study evaluated posterior three-unit fixed dental prostheses (FDPs) made of zirconia substructures veneered with pressable glass-ceramic. Nineteen patients received 21 FDPs replacing either the second premolar, first molar, or second molar. The FDPs were cemented with glass ionomer. Recall examinations were performed every 12 months. The mean service time of the FDP was 40 months. At 30 months, one maxillary FDP exhibited zirconia framework fracture at a thinned occlusal area of the abutment. Loss of retention led to the removal of one FDP after 38 months. The Kaplan-Meier survival probability was 90.5% after 40 months for all types of failures and 95.2% concerning framework fractures. The overpressing technique appears to be reliable in terms of the veneering material. However, one framework fracture was observed in this study.

The purpose of this in vitro study was to compare the precision of fit of substructures milled from semi-sintered zirconia blocks fabricated with two different computer-assisted design (CAD)/computer-assisted manufacturing (CAM) systems. Three-unit posterior fixed dental prostheses (FDP) were fabricated for standardized dies (n = 10) with the Lava CAD/CAM system (Lava) and the Procera-bridge-zirconia CAD/CAM system (Procera). After cementation to the dies, the FDP were embedded and sectioned. Four cross-sections were made of each abutment tooth, and marginal and internal fit were evaluated under an optical microscope. A one-way analysis of variance was used to compare data (alpha = 0.05). Mean gap dimensions at the marginal opening for Lava and Procera were 15 (+/-7) microm and 9 (+/-5) microm, respectively. Mean marginal openings (P = 0.012) and internal adaptation at two out of three measurement locations were significantly different. Within the limitations of this study, the results suggest that the accuracy of both investigated systems is satisfactory for clinical use.

STATEMENT OF PROBLEM: The mechanical properties of polyetheretherketone (PEEK) make it an ideal material for fixed dental prostheses; however, insufficient information is available about the cementation of these restorations. PURPOSE: The purpose of this study was to evaluate the retention strength of differently pretreated and conditioned PEEK crowns luted to dental abutments. MATERIAL AND METHODS: Human teeth were prepared in a standardized manner, and PEEK crowns were milled (N=160, n=10 per group) and conditioned as follows: airborne-particle abrasion, sulfuric etching, piranha etching, and no conditioning. These groups were divided into adhesive systems: visio.link, Signum PEEK Bond, Ambarino P60, and no adhesive and luted to dentin abutments. After water storage (60 days) and thermocycling (5000 cycles, 5°C/55°C), the retention strength of the crowns was determined with a pull-off test, and failure types were classified. The data were analyzed with the Kruskal-Wallis, 1-way ANOVA, and (2) test (=.05). RESULTS: Crowns that were unconditioned and piranha etched and/or adhesively untreated or pretreated with Ambarino P60 had the lowest retention strength. The highest values were found for the airborne-particle abrasion and sulfuric etched groups and/or crowns adhesively pretreated with Signum PEEK Bond and visio.link. Composite resin cement that remained on dentin was observed more frequently for unconditioned groups in combination with Ambarino P60 and no adhesive pretreatment. Mixed failure types were found more frequently in the airborne-particle abrasion group in combination with visio.link, Signum PEEK Bond, and no adhesive pretreatment, in the sulfuric acid etched group combined with Ambarino P60 and no adhesive pretreatment, and after the piranha acid pretreatment in combination with visio.link or Signum PEEK Bond. CONCLUSIONS: The adhesion of the tested PEEK crowns to dentin was satisfactory after treatment with airborne-particle abrasion or etching with sulfuric acid and/or when additional adhesive systems such as visio.link or Signum PEEK Bond were used. The effect of surface modification on the retention strength of PEEK crowns adhesively bonded to dentin abutments Statement of problem. The mechanical properties of polyetheretherketone (PEEK) make it an ideal material for fixed dental prostheses (FDPs); however, insufficient information is available about the cementation of these restorations.Purpose. The purpose of this study was to evaluate the retention strength of differently pretreated and conditioned PEEK crowns luted to dental abutments. Material and methods.Human teeth were prepared in a standardized manner and PEEK crowns were milled (N=160, n=10 per group) and conditioned as follows: airborne-particle abrasion, sulfuric etching, piranha etching, and no conditioning. These were divided into adhesive systems: visio.link, Signum PEEK Bond, Ambarino P60, and no adhesive and luted to dentin abutments. After water storage (60 days) and thermocycling (5000 cycles, 5°C/55°C), the retent...

OBJECTIVES: The aim of this study is to evaluate the adhesion between PEEK and two selfadhesive resin cements after plasma treatment. METHODS: Eight hundred sixty-four polyetheretherketone (PEEK) disks were cut and polished to silicon carbide (SIC) P4000. One half of the specimens were randomly selected and pretreated with plasma, whereas the remaining 432 specimens remained untreated. Subsequently, specimens were randomly allocated to four groups (n = 108/group): Visio.link (Bredent), Signum PEEK Bond (Heraeus Kulzer), Ambarino P60 (Creamed), and a control group without additional treatment. Half of the specimens of each group (n = 54) were then cemented with either RelyX Unicem Automix 2 (3 M ESPE) or with Clearfil SA (Kuraray). All specimens were stored in water for 24 h (37°C ). Afterwards, specimens were divided into three groups (n = 18) for different aging levels: (1) no aging (baseline measurement), (2) thermal aging for 5,000 cycles (5/55°C), and (3) thermal aging for 10,000 cycles (5/55°C). Thereafter, shear bond strengths (SBS) were measured, and failure types (adhesive, mixed, and cohesive) were assessed. Data were analyzed using descriptive statistics, four-and one-way ANOVA followed by a post hoc Scheffé test (p < 0.05). RESULTS: No adhesion could be established without adhesive pretreatment, irrespectively, whether plasma was applied or not. Also, no bond strength was measured when Ambarino P60 was applied. In contrast, adhesive pretreatment resulted in SBS ranging between 8 and 15 MPa. No significant differences were found between the resin cements used. In general, no cohesive failures were observed. Groups without plasma treatment combined with Visio.link or Signum PEEK Bond showed predominantly mixed failure types. Control groups, plasma treated, or treated using Ambarino P60 groups fractured predominantly adhesively. CONCLUSION: The use of methyl methacrylate (MMA)-based adhesives allows bonding between PEEK and self-adhesive resin cements. Plasma treatment has no impact on bond to resin cements. CLINICAL SIGNIFICANCE: PEEK reconstructions can be cemented using self-adhesive resin cements combined with pretreatment with MMA-based adhesives. Methods: Eight-hundred-and-sixty-four PEEK disks were cut and polished to silicon carbide (SIC) P4000. One half of the specimens was randomly selected and pre-treated with plasma, whereas the remaining 432 specimens remained untreated. Subsequently, specimens were randomly allocated to four groups (n=108/group): Visio.link (Bredent), Signum PEEK Bond (Heraeus Kulzer), Ambarino P60 (Creamed) and a control group without additional treatment. Half of the specimens of each group (n=54) were then cemented with either RelyX Unicem Automix 2 (3M ESPE) or with Clearfil SA (Kuraray).All specimens were storage in water for 24 h (37°C). Afterwards, specimens were divided into three groups (n=18) for different aging levels: i. no aging (baseline measurement), ii.thermal aging for 5000 cycles (5/55°C) and iii. thermal aging for 10000 cycles (5/55°C).Thereafte...