Resin Ionomer Restoration: A Ray of Hope for Furcation Therapy – Case Report

INTRODUCTION

Furcation involvements are recognized as a challenge to periodontal therapy. Loss of attachment in furcation, is strongly correlated with sub gingival plaque¹. Treatment attempts range from non- surgical therapy, furcation obliteration, surgery to increase access to the furcation, gingivectomy, apical repositioned flaps and certain regenerative techniques using membranes and bone grafts.^2,3

In the past, restorative materials have been used to obliterate furcations.² The goal was to improve plaque control by eliminating the anatomic niches within the furcation where bacteria can accumulate. Klingsberg et al.⁴ advocated the use of polymeric- reinforced zinc oxide-eugenol (IRM). They reported clinical success for up to 5 years, stating the material was physiologically accepted by the gingiva, prevented caries, and simplified the patient's plaque control. Van Swol and coworkers⁵ utilized amalgam restorations to fill Class II furcation invasions. They presented 2 case reports stating that treatment resulted in a clinically healthy environment, but noted on 1-year radiographic follow- up, radiolucency at the base of the restoration.

Resin ionomer materials possess many properties that allow them to function successfully in subgingival locations and be  well tolerated by the periodontium⁷. Scherer and Dragoo^[6,7]  utilized modified resin- ionomer restorations in subgingival locations. They demonstrated histologic evidence that both epithelium and connective tissue can adhere to the resin ionomer when placed in a subgingival environment. The authors reported that the gingival tissues tolerated the material well and felt that resin ionomers possess biocompatibility with the periodontium.

A case report is presented here, using a subgingival resinionomer restoration as an occlusive barrier in the treatment of a Class II furcated maxillary molar.

CASE REPORT

A female patient aged 34 years reported to the Department of Periodontology, Maratha Mandal's Nathajirao G Halgekar Institute of Dental Sciences and Research Centre, with sensitivity on having cold water in the upper right back teeth. Past dental history revealed that the patient had undergone extraction of 36, 3 months back. An extra oral examination revealed no abnormality. Medical history was non contributory. On intraoral examination maxillary right 1^st molar (16) revealed a Class II furcation involvement on buccal aspect and a Class III (Miller's classification) recession considering the loss of interdental bone on the mesial aspect. (Figure 1 a). A probing depth of 9 mm and 5mm was present on mesiobuccal and midfacial aspect of 16 respectively. On radiologic examination 16 revealed radiolucency at the furcation area and an interproximal bone loss at the mesial aspect of the same tooth (Figure 1 b). Electric pulp test was performed to check the vitality of 16 , and the tooth had a similar response to that of the neighbouring teeth , indicating that the tooth is vital.

Periodontal disease discussion and oral hygiene instructions were provided to the patient during her first visit. Treatment options were discussed. Necessary scaling and root planing was performed and the patient consented to the surgery. Surgery was deemed necessary to access the furcation, scale and plane the surfaces, and place a resin-ionomer restoration to seal the furcation at tooth no. 16.

Surgical technique

Patient was subjected to surgery 4 months after phase 1 therapy. Prior to surgery, the patient rinsed for 60 seconds with 0.2 % chlorhexidine mouth rinse. Surgery was carried out using aseptic precautions. Following local anaesthesia using local infiltration of 2% lidocaine with a concentration of 1:80,000 epinephrine, sulcular incisions were made and a full thickness mucogingival flap was reflected from tooth number 14 to 17, to expose the furcation area.

Debridement was done using standard Gracey curette (Hu Friedy). After debridement a 3mm horizontal component defect was revealed in the furcation area and a 3mm vertical defect combined with a hemiseptal defect on the mesial aspect of 16 (Figure 2 a and b ). A sharp bony margin was seen on the mesial aspect of 16 where osteoplasty was performed by using bone file (Fs3/4s Hu Friedy's Schluger and Sugarman file). (Figure 3)

The furcation area was etched by using 37 % phosphoric acid for 60 seconds followed by a sterile water rinse. The etching solution was applied to remove the smear layer and prepare the root surface. The powder and liquid of the resin ionomer restoration (GC gold label light cured universal restorative material, GC cooperation Tokyo Japan) was mixed at the ratio of 2.9: 1 and was placed in the defect by using plastic filling instrument. It was then light cured for 60 seconds (Figure 4 a and b).

Excess resin was removed; finished using finishing burs and the area was burnished (Figure 5). Flap was replaced and sutured using 3-0 silk suture material (Figure 6). A periodontal dressing (COE PAK) was given. The patient was prescribed Amoxicillin 500mg three times a day, for 5 days and Ibuprofen Paracetamol combination three times a day for 3 days. Post operative instructions were given. Sutures were removed after 7 days. No intraoperative or post operative complications were seen. Healing was uneventful. The patient voiced no complaints of discomfort.

The patient was seen for follow up at approximately every 2 weeks for 1^st one month and then after every 3 months (Figure 7 a). The 9 months post operative clinical finding revealed a completely sealed furcation with respect to 16. (Figure 7 b). The probing depths were reduced to 2 mm on the buccal aspect and 4 mm on the mesiobuccal aspect of 16. A radiograph was taken revealing excellent fill of the furcation with the restorative material (Figure 8).

DISCUSSION

The result of this case points out that the prognosis of the furcated maxillary molar can be improved by using an occlusive barrier, such as a resin-ionomer restoration. Not only does the barrier seal the furcation entrance from epithelial, bacterial, and food debris invasion, but may enable easier home care due to less surface area of the furcation.

Resin-ionomers, since their introduction to dentistry , have increasingly been used in restorations, cements, cavity liners, post-and core build-ups and preventive applications.⁸ it possesses the following characteristics and advantages: 1) insolubility in oral fluids; 2) increased adhesion to tooth structure and other dental substrates; 3) dual-cure capabilities; 4) low cure shrinkage; 5) low coefficient of thermal expansion; 6) radiopacity; 7) fluoride release; and 8)biocompatibility.⁹

Potential advantages of an occlusive barrier such as a resinionomer are: 1) easy to place into a furcation; 2) does not require a suture for stability; 3) elimination of a second stage procedure for retrieval of the membrane since it is permanently bonded; 4) epithelial attachment; 5) does not require complete coverage by the gingival flap; 6) bacteriostatic due to fluoride release; 7) lower cost since it is dispensed in a multi-use tube; and 8) no chance of transmission of viral infection.⁸

Fowler and Breault¹⁰ used a resin ionomer restoration to seal a furcation defect of a molar in a patient with severe periodontitis. Early healing was uneventful, but at 11 weeks, it was noted that suppuration was present in the buccal surface of the molar. The area was treated with local chemotherapeutics, but nine months after surgery, the tooth was extracted. But in our case, even at 9 months post operative, the gingival and periodontal tissues were not adversely affected by the material. The probing depths were reduced to 2 mm on the buccal aspect and 4 mm on the mesiobuccal aspect of 16. Fowler et al study was a case of severe periodontitis with a Class III furcation which was also endodontically involved.

The goal in selecting this mode of therapy was simply to seal the furcation.

This case shows that the resin ionomer restorative material may be safely used to fill furcation defects. More such clinical data to strengthen the scientific evidence of the use this material is suggested.