Shimizu et al.

Asian Pac J Dent 2011; 11: 51-53.

Use of a light-activated composite resin to adjust intaglio surfaceof removable prosthesis
Hiroshi Shimizu, DDS, PhD, Tomohiro Kawaguchi, DDS, and Yutaka Takahashi, DDS,PhD
Division of Removable Prosthodontics, Department of Oral Rehabilitation, Fukuoka Dental College,Fukuoka, Japan
This article presents a methodical procedure that facilitates the use of a light-activated composite resin to add
and adjust the intaglio surface of a removable prosthesis to accommodate root copings. A surface preparation
for methyl methacrylate resin was used to ensure the bonding between a light-activated composite resin anddenture base resin. (Asian Pac J Dent 2011; 11: 51-53.)
Key Words: bonding, denture base resin, light-activated composite resin

Introduction
Patients frequently wish to complete the procedure for replacing missing teeth in a short period of time.
Despite, the conventional procedure for an overdenture treatment is time consuming because root copings must
be made and cemented prior to fabrication of a removable prosthesis. Even if the time saving technique1 for thefabrication of root copings is used, additional multiple patient’s visits must be required when compared tofabrication of the ordinary removable prostheses. Therefore, it sometimes can be recommended the fabricationand insertion of a removable prosthesis to restore aesthetics or function in the first place followed by cementingof root copings. Autopolymerizing acrylic repair resin has been generally used in such cases mainly due to its
easy handling. However, there are porosities within the matrix and cracks between the matrix and poly(methylmethacrylate) particles in this material.2,3 This unsound character of autopolymerizing acrylic repair resin may
introduce poor mechanical property,2 discoloration, staining and an accumulation of microorganisms.
A light-activated gingiva-colored composite resin has been used for a portion of an implant infrastructure toprovide shades as seen in the natural gingiva.4 It was assumed that this new resin can be used instead of
autopolymerizing acrylic repair resin using some surface preparation for denture base resin prior to apply. This
article presents a methodical procedure that facilitates the use of a light-activated composite resin to add andadjust the mucosal denture surface of a removable prosthesis to accommodate root copings.

Technique
Fabricate, insert and adjust a new removable partial denture prior to making and cementing of root copings(Fig. 1). Prepare the root surface and post space of the abutment teeth, make combined definitive impressions
with vinyl polysiloxane impression material (Exafine, putty type and injection type; GC Corp, Tokyo, Japan),fabricate the root copings using a silver-palladium-copper-gold alloy (Castwell M.C. 12; GC Corp) byconventional means and cement them to the roots of the abutment teeth (Fig. 2). Make the escape holes from theintaglio surface to the polished denture surface of the lingual region of the removable partial denture (Fig. 3).
Make the intaglio space for root copings with an appropriate rotary instrument and treat the ground surface using
tribochemical silicate coating system (Rocatec adhesive bonding system; 3M ESPE AG Dental Products, Seefeld,Germany) with 110 µm grain-sized alumina (Rocatec Pre; 3M ESPE AG Dental Products), 110 µm grain-sizedalumina coated with silicon dioxide (Rocatec Plus; 3M ESPE AG Dental Products) and silane coupling agent

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Asian Pac J Dent 2011; 11: 51-53.

(Rocatec ESPE-Sil, 3M ESPE AG Dental Products) in accordance with the manufacturer’s specifications (Fig.
4).

Fig. 1. Removable partial denture in patient’s oral cavity.

Fig. 2.

Cemented root copings.

Fig. 3.
Fig. 4.

Escape holes from the intaglio surface to the polished denture surface (left).
Prepared intaglio surface of removable partial denture using tribochemical silicate coating (right).

Fig. 5.
Fig. 6.

Adding of light-activated gingiva-colored composite resin (left).
Pre-polymerization with the light source from the polished denture surface direction (right).

Add light-activated gingiva-colored composite resin (Gradia Gum, GC Corp) to the freshly prepared intaglio
surface of denture base (Fig. 5). Lubricate the root copings with petroleum jelly as a separating agent. Insert
and place the removable partial denture into position. Pre-polymerize with the light source (G-Light; GC Corp)
for 30 s from the polished denture surface direction (Fig. 6). Remove the removable partial denture and thencomplete a final polymerization from the intaglio surface direction in a light- polymerization unit (UniXS II,Heraeus Kulzer, Wehrheim, Germany) for 3 minutes. Polish the polished denture surface around the escapeholes of the removable partial denture and adjust intraorally (Figs. 7 and 8).

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Fig. 7.
Fig. 8.

Asian Pac J Dent 2011; 11: 51-53.

Intaglio view of adjusted removable partial denture (left).
Occlusal view of completed polished denture surface (right).

DiscussionIt is difficult to bond a light-activated composite resin each other5 or to acrylic denture base resin. The reason
for the poor bonding capability of a light-activated composite resin may be the low resin component amounts ofit. It was reported that the tribochemical silica coating method for a light-activated composite resin wereeffective for bonding to denture base resin.6 The tribochemical silica coating method is a procedure that uses
impact energy to apply a silicate coating to a target surface. This system was originally introduced to enhance
the bonding of resin composites to metallic dental materials.7 It appears that the reference 6 was the first toattempt to apply tribochemical silicate coating system in order to prepare surface of a denture base resin. The
combined use of dichloromethane and silane coupling agent6 as well as the application of chemically activated
4-META resin using the brush-dip technique8 for a light-activated composite resin have also effect on bonding toacrylic denture base resin. Long-term clinical check-up should be necessary to evaluate this method as avaluable treatment option.

References
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Ogawa T, Hasegawa A. Effect of curing environment on mechanical properties and polymerizing behavior of methylmethacrylate autopolymerizing resin. J Oral Rehabil 2005; 32: 221-6.
Hagiwara Y, Nakajima K, Tsuge T, McGlumphy EA. The use of customized implant frameworks with gingiva-coloredcomposite resin to restore deficient gingival architecture. J Prosthet Dent 2007; 97: 112-7.
Hisamatsu N, Atsuta M, Matsumura H. Effect of silane primers and unfilled resin bonding agents on repair bond strength of a
prosthodontic microfilled composite. J Oral Rehabil 2002; 29: 644-8.
Shimizu H, Kawaguchi T, Yoshida K, Tsue F, Takahashi Y. Effect of surface preparation on the failure load of a highly filled
composite resin bonded to a denture base resin. J Prosthodont 2009; 18: 684-7.
Matinlinna JP, Vallittu PK. Silane based concepts on bonding resin composite to metals. J Contemp Dent Pract 2007; 8: 1-8.
Shimizu H, Kawaguchi T, Mutobe H, Kiyokuni Y, Takahashi K, Takahashi Y. Bonding of a gingival shade composite to adenture base resin using a chemically activated 4-META resin. Eur J Prosthodont Restor Dent 2011; 19: 7-10.

Correspondence to:Dr. Hiroshi Shimizu
Division of Removable Prosthodontics, Department of Oral Rehabilitation, Fukuoka Dental College
2-15-1, Tamura, Sawara-ku, Fukuoka 814-0193, Japan
Fax: +81-92-801-0513 E-mail: simizuh1@college.fdcnet.ac.jp
Accepted December 8, 2011.
Copyright ©2011 by the Asian Pacific Journal of Dentistry.
Online ISSN 2185-3487, Print ISSN 2185-3479

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