Effect of phosphoric acid and sodium hydroxide on cleaning and bonding of saliva-contaminated feldspar porcelain

Abstract

Hydrofluoric acid has been used to remove salivary contamination in dental glass-ceramics before bonding treatment. However, alternative methods are required because hydrofluoric acid is harmful. This study examined the cleaning effects of phosphoric acid and sodium hydroxide on glass-ceramics for bonding pre-treatment. Methods: Feldspar porcelain was divided into four groups: (C) cleaned porcelain without any contamination, (S) porcelain contaminated with saliva, (SPA) porcelain cleaned with 37% phosphoric acid after saliva contamination, and (SSH) porcelain cleaned with 10% sodium hydroxide after saliva contamination. Each sample was bonded to the resin cement using a silane-containing primer. They were then subjected to a shear bond strength (SBS) test. Each surface was analyzed by scanning electron microscopy (SEM), contact angle measurements, and Fourier transform infrared spectroscopy (FT-IR). Results: The SBS of group SSH was comparable to that of group C but significantly higher than that of groups S and SPA. SEM observations showed that saliva-like structures remained on the samples of groups S and SPA, but not on the SSH group. The contact angles of groups C and SSH were comparable and significantly smaller than those of groups S and SPA, respectively. FT-IR analysis also revealed saliva in groups S and SPA, which was absent in the SSH group. Conclusion:The saliva remained on the porcelain even after cleaning with phosphoric acid, and SBS was not restored to the same level as before the contamination. In contrast, sodium hydroxide eliminated saliva and restored SBS to the same level as before contamination.

Clinical Survival Rate and Laboratory Failure of Dental Veneers: A Narrative Literature Review

“…Debonding is another important complication documented in the literature; the causes of debonding are summarized in Table 2 [8,13,16,17,[28][29][30][31][32][33][34][35][36][37][38][39][40][41]. Debonding is related to the poor bond strength between the internal surface of the veneer and the resin cement, between the prepared tooth and the resin cement layer, or within the resin cement.…”

“…Debonding is related to the poor bond strength between the internal surface of the veneer and the resin cement, between the prepared tooth and the resin cement layer, or within the resin cement. Adhesive failure between the tooth and resin cement is related to dentin exposure (>50%) [42], the presence of large composite restorations [28], poor surface treatment of the tooth, and contamination [40].…”

“…Saliva can be controlled with lip retractors. Bleeding can be controlled by astringents (aluminum chloride) [40].…”

“…The adhesive failure between the ceramic and resin cement is caused by poor surface treatment of the veneer internal surface and contamination [40]. Zirconia veneers fail mainly due to debonding [11]; this occurs when the adhesive between the zirconia and resin cement fails because the zirconia is purely polycrystalline, with no glass.…”

Influence of the thickening agent contained in a phosphoric acid etchant on bonding between feldspar porcelain and resin cement with a silane coupling agent

“…For instance, they remove salivary contaminants from the glass-ceramic surface, restoring the bonding strength between the glass-ceramic and resin cement [12][13][14] . Although the ability of PA etchants to remove saliva is inferior to that of alkaline solutions 15) , they can be potentially used as cleaning agents. Thus, a PA etchant was utilized as a surface conditioner to increase the bonding strength between glass-ceramics and resin cement [16][17][18] .…”