Bond strength of artificial teeth to thermoplastic denture base resin for injection molding

Abstract

This research was conducted to investigate the bond strength between artificial teeth and a thermoplastic denture base resin for injection molding with different surface preparations for use in flexible resin removable partial dentures. Composite resin denture teeth and acrylic denture resin teeth were bonded to three types of thermoplastic denture base resins for injection molding (polyamide, polyester, and polycarbonate) and a conventional heat-polymerized polymethyl methacrylate (PMMA) resin (control). The ridge lap surfaces of the artificial teeth were classified into four groups based on the type of ridge lap surface treatment applied (n=10): no treatment, ethyl acetate, small T-shaped tunnel, and large T-shaped tunnel. The specimens were tested for bond strength. The results showed that the ethyl acetate treatment was ineffective for enhancing the bond strength (p>0.05) between the artificial teeth and thermoplastic denture base resin for injection molding, whereas the T-shaped tunnel was quite effective in this regard (p<0.05).

The influence of the retention feature in artificial teeth on its attachment to the thermoplastic resin denture base

“…One of the most common causes for partial denture wearers to return to the dental office is the tooth dislodgment of the artificial tooth from the denture base. There is little discussion available regarding the thermoplastic polymer vulnerability [3,11] when compared to studies for acrylic resin teeth adhesion to its denture base [6,9,10]. This has been theorized as a consequence of the lack of residual monomer in TR, differently from the acrylic resin base.…”

“…Lateral and Central incisors presented no statistically significant results when comparing GI and GII. It has been reported that the hole diameter of the retentions might influence bond strength of the artificial [3], therefore an analysis with different sizes of burs might be necessary.…”

“…The sight of metal clasps of the removable partial dentures (RPDs) in the patient's smile will be disappointing to him both cosmetically and psychologically [2]. An alternative removable partial denture has been developed that avoid the use of conspicuous clasps [3] by employing thermoplastic polymers (TR) and injection molding which eliminate the need for metal retainers [2]. Polyamide, polyester, polycarbonate and polypropylene are examples of polymers which offer a more pleasing result.…”

“…But perhaps the most troublesome problem with these materials is the frequently observed detachment of the artificial denture teeth from the base [4][5][6][7]. While acrylic resin teeth (ARAT) are chemically bonded to conventional polymethyl methacrylate (PMMA) resins, artificial teeth have no chemical interaction with the thermoplastic polymer denture and, as such, are susceptible to dislodgement [3].…”

Flexible Denture: A Literature Review

“…They divided samples into the following groups based on surface treatment: group 1 (no surface treatment), group 2 (an ethyl acetate treatment), group 3 (a small T- groove-shaped), and group 4 (a large T-shaped tunnel). In the Valplast group, the bond strength value of the large T-shaped tunnel in composite resin denture teeth was the highest [ 25 ]. The researchers examined the differences in bond strength between acrylic teeth and the polyamide denture base with the three surface treatments (sandblasting, T-shaped diatoric holes, or both).…”