Repair bond strength of composite: Effect of surface treatment and type of composite

Abstract

BackgroundBy an increase in use of composite restorations, some defects are also seen in these restorations, which need to be repaired. Since complete replacement of an old restoration may compromise the tooth structure, repair of defect is a more practical approach if there is no caries recurrence. Risk of pulp injury also decreases as such. One major challenge in restoration repair is to obtain a durable bond between the new and old composite. Laser irradiation has been suggested for surface preparation of old composite. This study aimed to assess the effect of composite surface preparation with Er,Cr:YSGG laser on microtensile bond strength to new composite.Material and MethodsA total of 18 blocks were fabricated in three groups of nanohybrid, microhybrid and Beautiful II giomer measuring 4x7x7 mm and subjected to 10,000 thermal cycles between 5-55°C with 30 seconds of dwell time. The samples were randomly assigned to no surface treatment (etching and bonding) or laser plus etching and bonding groups. Composite cylinders measuring 4x7x7 mm were fabricated of Beautiful, nanohybrid and microhybrid composites on old composite surfaces and subjected to 500 thermal cycles for 50 seconds between 5-55°C with 30 seconds of dwell time. Each block was sectioned into 10 samples and they were subjected to microtensile bond strength test. Data were analyzed using ANOVA and Tukey’s test.ResultsIn all composites, the mean bond strength in laser subgroups was higher than that in control subgroups except for giomer, which showed lower bond strength in laser subgroup. The lowest mean bond strength was noted in repair of Z350XT with Z350XT when the surface of old composite was etched (10.92 MPa). The highest mean bond strength was noted in repair of Z250 with giomer when the old composite surface was irradiated with laser (30.55 MPa).ConclusionsEr,Cr:YSGG laser plus etching increased the bond strength in all groups except for giomer group, which showed a reduction in bond strength. Key words:Composite resins, surface treatment, tensile bond strength, laser, er,cr:ysgg, giomer.

Bond strength repair of a bulk-fill composite using different adhesive systems and resin composites

“…An important step for success of repair procedure is the surface asperization, that has the function of increasing the surface roughness and consequently increasing the bond strength by mechanical adhesion (Brunton et al, 2017). Some (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v10i5.14951 methods have been evaluated for this purpose, such as aluminum oxide blasting, diamond tip asperization, laser pretreatment, hydrofluoric and phosphoric acid application, among others (Duran et al, 2015;Brunton et al, 2017;De Jesus et al, 2017;Fornazari et al, 2017;Ghavam et al, 2018;Ayar et al, 2019). Microporosities creation using diamond-tip in high rotation propitiates the micro-retention of resin-based materials, showing effectiveness in adhesion increase of way practical and accessible for clinicians (De Jesus et al, 2017;Ghavam et al, 2018), thus this method was selected in the present study for roughening of aged composite.…”

Repair bond strength and surface topography of resin‐ceramic and ceramic restorative blocks treated by laser and conventional surface treatments

“…No clear information about the minimum threshold bonding strength that can be accepted for restoration repair is available (Ghavam, Naeemi, Hashemikamangar, Ebrahimi, & Kharazifard, 2018).…”

“…The minimum repair bond strength required in the repair of restorations can be considered as a minimum of 15 MPa as mentioned in previous studies (Ghavam et al, 2018;Kiomarsi et al, 2017;Oglakci & Arhun, 2019). Thus, it is important to apply the appropriate surface treatment to restoration material while undertaking a repairing procedure.…”

Evaluation of Surface Preparations Combined With Different Generations of Bonding on the Bond Strength of Resin Composite Repair: An Original Article

“…Chemical and mechanical damages can destroy composite restorations during their service period. Clinical studies revealed 5%-45% failure rate during a 5-year period in this regard (1)(2)(3). It has been demonstrated in a clinically simulated study that more than twice as much tooth structure is lost when removing composite restorations than comparable amalgam restorations (4).…”

“…Previous studies showed that the bond will be so weak if the adhesive is not applied after surface preparation (16,25). Despite many studies, there is still no agreement on the best composite repair protocol (2,11,26,27). Therefore, a combination of mechanical/chemical preparation and bonding agents has been used in this regard (28,29).…”