A castor oil-containing dental luting agent: effects of cyclic loading and storage time on flexural strength

Abstract

Favorable results in the use of castor oil polyurethane (COP) as pulp capping, membrane material, sealer, mouthwash and in bone repair, associated with the fact that Ricinus communis is not derived from petroleum and it is abundant in Brazil, encourage researches in the development of luting agents. Objectives This study compared the flexural strength (FS) of a castor oil-containing dental luting agent with a weight percentage of 10% (wt%) of calcium carbonate (COP10) with RelyX ARC (RX) after mechanical cycling (MC) and distilled water storage.Material and Methods Sixty-four specimens (25x2x2 mm) were fabricated and divided into two groups, COP10 and RX (control). Each group was divided into 4 subgroups (n=8) according to the storage time, 24 hours (24 h) or 60 days (60 d), and the performance (MC+FS) or not (only FS) of the mechanical cycling test. The FS (10 kN; 0.5 mm/min) and MC tests (10,000 cycles, 5 Hz, 0.5 mm/min) were carried out using an MTS-810 machine. The data were analyzed using ANOVA (α=0.05).Results The obtained FS (MPa) values were: COP10 24h- 19.04±2.41; COP10 60d- 17.92±3.54; RX 24h- 75.19±3.43; RX 60d- 88.77±6.89. All the RX specimens submitted to MC fractured, while the values for COP10 after MC were as follows: COP10 24h- 17.90±1.87 and COP10 60d- 18.60±1.60.Conclusions A castor oil-containing dental luting agent with a weight percentage of 10% (wt%) of calcium carbonate is resistant to mechanical cycling without decreases in flexural strength. However, mean COP10 showed only about 25% of the RelyX ARC mean flexural strength.

Update on Dental Luting Materials

“…As castor oil polyurethane has good biocompatibility properties, osteo-inductive properties and antimicrobial abilities, it has great potential to be developed as a versatile dental material. Some studies have tested its use as a luting cement [ 141 , 142 , 143 ]. The luting material was presented as a two-part system with calcium carbonate fillers [ 142 ].…”

“…The luting material was presented as a two-part system with calcium carbonate fillers [ 142 ]. Although the flexural strength of castor oil polyurethane was only 25% of that of adhesive resin cement, it is comparable to the conventional cements such as zinc phosphate and GIC [ 143 ]. Modifications of castor oil polyurethane with the addition of different fillers to enhance its mechanical strength could be the direction of its future development.…”

Polyurethane derived from Ricinus Communis as graft for bone defect treatments

“…There are many polymers used in dentistry, such as silicone, polyurethane and methyl methacrylate. The vegetable polyurethane, which combines the versatility of polymer formulation with the global concern of new biomaterials production with sustainable resources, has become one of the most studied biomaterials [1,2] .…”

Behavior study of the doped castor bean polymer rod with bioactive glass and hidroxyapatite in mice femur medullary canal

“…In this way, the search for lighter, more resistant, low cost and biocompatible materials has grown 2 for more biological solutions and replacing artifacts such as wire rods and metal plates by bioreabsorbable polymers in the fractures treatment 3 . Among these polymers, polyurethane derived from castor oil has been outstanding because it is a low cost material developed in Brazil that has excellent structural properties, which has been shown to be biocompatible 4 , and for combining the versatility of the polymer formulation while addressing the global concern in the production of new biomaterial resources becoming one of the most studied 5 . Bioactive glasses have unique binding properties to the bone surface, their main characteristic being the ability to promote chemical bonding with hydroxyapatite and to act as a framework for bone growth 6 .…”