Better Glass-fiber Post Preservation in Teeth with Ferrule When Subjected to Chewing

Abstract

SUMMARY Objectives: To evaluate the influence of ferrule effect and mechanical fatigue aging on glass-fiber post push-out bond strength (PBS) to root-canal dentin at different root thirds of premolars. Methods and Materials: Thirty-two sound maxillary premolar teeth were collected, and randomly assigned to two experimental groups (n=16): ‘Remaining Dentin Ferrule’ (RDF) = coronal crown cut 2.0 mm above the cemento-enamel junction (CEJ); ‘Without Dentin Ferrule’ (WDF) = coronal crown cut at the cemento-enamel junction. Teeth were endodontically treated, post spaces were prepared up to 10.0-mm depth from CEJ, and glass-fiber posts were cemented using a dual-cure self-adhesive composite cement. Standardized cores were built using a light-cure composite, upon which tooth cores were prepared using a 1.5-mm taper ogival-end diamond bur. Crowns were handmade using self-cure acrylic resin and cemented using the aforementioned composite cement. Half of the specimens were subjected to 1,200,000 cycles of mechanical fatigue in a chewing simulator (F = ‘Fatigue’), while the other half were stored in distilled water at 37°C for 1 week (C = ‘Control’). All specimens were horizontally sectioned into 1.0-mm thick slices prior to PBS test; the failure modes were assessed using stereomicroscopy and scanning electron microscopy (SEM). Data were analyzed for each root third using two-way analysis of variance (ANOVA) followed by Tukey HSD post-hoc test; frequency distribution was compared by Chi-square test (α=0.05) and post-hoc comparisons with Bonferroni. Results: The mean PBS in MPa (SD) were = RDF_F = 10.4 (2.9); WDF_F = 6.9 (1.7); RDF_C = 14.5 (2.7); WDF_C = 14.2 (2.9). Similar PBS were found for the root thirds. For all root thirds, significant differences were found for both the factors Dentin Ferrule and Fatigue, and their interaction (p<0.05). The lowest PBS was found for specimens without dentin ferrule subjected to chewing fatigue (p<0.001). Most failures occurred at the composite cement/dentin interface, followed by mixed and composite cement/glass-fiber post interfacial failures. There was a significant increase in mixed failures for the WDF_F group (p<0.001). Conclusion: Absence of 2.0-mm remaining dentin ferrule in premolars resulted in a higher decrease of the glass-fiber posts’ PBS to dentin after mechanical fatigue, irrespective of root third.

Effect of antioxidants after post‐space irrigation on the adhesive interface of glass fiber post cementation

“…17,18 Oxygen species can interact with the oxidative radicals of the resin-based system and negatively interfere in the polymerization reaction as well as occupy the space in the dentin. 1,19 Previous studies have shown that sodium hypochlorite decreases the bond strength of glass fiber posts to dentin. 20,21 Regardless of the third, the bond strength of the SH group was lower than other groups (P < 0.05).…”

“…The sodium hypochlorite solution dissociates into sodium hydroxide and hypochlorous acid, generating singlet oxygen 17,18 . Oxygen species can interact with the oxidative radicals of the resin‐based system and negatively interfere in the polymerization reaction as well as occupy the space in the dentin 1,19 . Previous studies have shown that sodium hypochlorite decreases the bond strength of glass fiber posts to dentin 20,21 .…”

“…Glass fiber posts are indicated to restore teeth with extensive loss of structure. These posts have a coefficient of thermal expansion, modulus of elasticity, flexural and compressive strength very similar to the tooth, in addition to presenting favorable esthetic properties 1 . Prior to post‐cementation, the post‐space must be irrigated with a solution capable of removing the smear layer, clearing dentinal tubules, as well as presenting antimicrobial activity 2,3 to improve the adhesion of the post to the tooth structure.…”

The Effect of Remaining Coronal Tissue Height on the Fracture Strength of Over-Flared Endodontically Treated Central Incisors Restored Using a Multipost Approach

“…After 1 min of silanization (Silano, Angelus, Brazil) and applying 96% ethanol, two prefabricated fiberglass posts, including primary Number #1 fiber with a coronal diameter of 1/4 mm (Exacto, Angelus, Brazil) and one accessory fiber (Reforpin, Angelus, Brazil) with a coronal diameter of 1.3 mm, were simultaneously cemented into the root canal using dual-cure resin cement (duo-LINK Universal; Bisco Inc., Schaumburg, IL, USA) according to the manufacturer's instruction. A light cure device (Bluephase 20i, Ivoclar Vivadent, Schaan, Liechtenstein) with an intensity of 1,200 mW/cm 2 was used for 40 s according to the manufacturer's instructions [ 16 ]. A two-step etch-and-rinse adhesive (Single Bond 2, 3M Oral Care) was used to bond the coronal area.…”

Influência do diâmetro na resistência flexural de pinos de fibra de vidro

“…Não obstante, para ter indicação de pino é necessário observar a oclusão do paciente, posição do dente na arcada, sua função, configuração do canal e a quantidade de estrutura dental remanescente (Feuser et al, 2005;Veeraganta et al, 2020;Gré et al, 2021) .…”