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Investigation of the effectiveness of surface treatments that promote a strong bond strength of resin cements to metals can contribute significantly to the longevity of metal-ceramic restorations. This study evaluated the effect of surface treatments on the shear bond strength (SBS) of a resin cement to commercially pure titanium (CP Ti). Ninety cast CP Ti discs were divided into 3 groups (n=30), which received one of the following airborne-particle abrasion conditions: (1) 50 microm Al(2)O(3) particles; (2) 30 microm silica-modified Al(2)O(3) particles (Cojet Sand); (3) 110 microm silica-modified Al(2)O(3) particles (Rocatec). For each airborne-particle abrasion condition, the following post-airborne-particle abrasion treatments were used (n=10): (1) none; (2) adhesive Adper Single Bond 2; (3) silane RelyX Ceramic Primer. RelyX ARC resin cement was bonded to CP Ti surfaces. All specimens were thermally cycled before being tested in shear mode. Failure mode was determined. The best association was Rocatec plus silane. All groups showed 100% adhesive failure. There were combinations that promote higher SBS than the protocol recommended by the manufacturer of RelyX ARC.

Among the repair systems evaluated, those which use the tribochemical silica-coating procedure can be considered good options for repairing exposed titanium surfaces. Furthermore, the Cojet system's failure mode and stable behavior after water storage seems to indicate its use for a titanium surface repair technique. SUMMARYThis study evaluated the shear bond strength (SBS) and stability of commercially pure titanium (CP Ti)/repair material interfaces promoted by different repair systems. One hundred CP Ti cast discs were divided into five repair system groups: 1) Epricord (EP); 2) Bistite II DC (BT); 3) Cojet (CJ); 4) Scotchbond Multi-Purpose Plus (SB) (control group); and 5) Cojet Sand plus Scotchbond Multi-Purpose Plus (CJSB). The specimens were stored in distilled water for 24 hours at 378C, thermal cycled (5000 cycles, 58-558C) and stored under the same conditions for either 24 hours or six months (n=10). SBS was tested and the data were analyzed by two-way analysis of variance (ANOVA) and Tukey test (a=.05). Failure mode was determined with a stereomicroscope (203). The repair system, storage time, and their interaction significantly affected the SBS (p,0.001). At 24 hours, CJSB exhibited the highest SBS value, followed by CJ. At six months, these two groups had similar mean SBS (p.0.05) and higher means in comparison to the other groups. For both storage times, BT , 2012, 37-3, 253-262 presented the lowest SBS, while the EP and SB groups did not differ significantly from one another (p.0.05). There were no significant differences in SBS between the storage times for the groups EP and CJ (p.0.05). The groups BT, SB, and CJSB showed 100% adhesive failure, irrespective of storage time. The CJSB group showed the highest SBS at both storage times. At six months, the CJ group exhibited a similar SBS mean value when compared to the CJSB group. Water storage adversely affected the groups BT, SB (control group), and CJSB.Considering SBS values, stability, and the failure mode simultaneously, the CJ group showed the best CP Ti repair performance.

Repairing fractured metal-ceramic prosthesis is a treatment alternative that can increase the restoration longevity, preserve dental structure, and/or the integrity of implant components, besides being a simple, low-cost technique. However, clinicians often see restoration repair as a challenge because of the many doubts regarding the procedures required to obtain satisfactory results. Therefore, the motivation to write this article is the need to provide instructions for clinicians dealing with a situation involving fractured porcelain, presenting an intraoral repair technique that can be used in cases of a fractured ceramic veneer of a fixed partial prosthesis. The technique consisted in treating the remaining ceramic surface and applying a microhybrid composite resin following the steps of a protocol that, according to scientific evidence, has promoted high bond strength to porcelain, in addition to being cost effective.