Journal of Oral Rehabilitation, 1990, Volume 17, pages 257-268

Clinical evaluation of two posterior composite resins: two-year results 1. S T A N G E L and R . Y . B A R O L E T * McGill University Faculty of Dentistry, Montreal and ^University Laval j^cole de Medicine Dentaire, Ste. Foy, Quebec, Canada


Two composite resins were evaluated for clinical acceptability as restorative materials in Class I and II cavities over a 2-year period. In addition, dispersed phase alloy was evaluated for comparison. All restorations were assessed for anatomical form, marginal integrity and marginal leakage using modified United States Pubhc Health Service (USPHS) criteria. At the 2-year recall, 96% of the composites and 100% of the amalgams were rated 'alpha' or 'bravo', using the parameters of assessment defined in this study. However, a significant number of shifts from the baseline, within the level of acceptability, had occurred. The two composites showed the greatest number of shifts for anatomical form and marginal leakage, while there were no differences between the composites and the amalgam for shifts in marginal integrity. Although a very high level of acceptability was determined for all of the materials, the frequency of rating change within categories for the composites was a cause of concern with regard to their long-term clinical use. Introduction

Consideration given to the restoration of posterior teeth with composite resin began shortly after its introduction in the 1960s. However, early composites, which showed rapid, generalized loss of material, were found to be unsatisfactory for restoring occlusal cavities (McCune, Cvar & Ryge, 1969; PhilHps et al., 1973; Eriksen, 1974; Leinfelder et al., 1975). The subsequent development of microfilled resins, modified fillers and photopolymerization led to improved performance of composites in the posterior dentition (Jorgensen & Asmussen, 1978; Lutz et al., 1979; Moffa & Jenkins, 1979; Wilder, May & Leinfelder, 1983). More recently, composite resins with varied particle size and distribution have been developed for use in occlusal cavities. A reasonable probability of success for these composites has been reported in studies of 3-5 years duration (Lutz et al., 1984; Wilson, Smith & Wilson, 1986; Tonn & Ryge, 1986; Timmons e^ a/., 1988). Although laboratory testing has been investigated as a method of predicting the clinical performance of posterior composite resins, randomized clinical trials still represent the best method for their overall evaluation. The purpose of this study was to determine the acceptability of two visible-light cured posterior composite resins for clinical use in Class I and II restorations. The two composites differed from each other with regard to particle type, size and loading. The parameters used for determination of acceptability were occlusal wear, marginal breakdown and interfacial leakage. Correspondence: Dr I. Stangel, McGill University Faculty of Dentistry, 740 Dr. Penfield, Montreal, P Q. H3A 1A4, Canada.



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Materials and methods The materials selected for use in this study were Heliomolar* and Fulfilt. A dispersed phase alloy, Dispersalloy,:}: was used to compare the clinical performance of the two composites with that of amalgam. The resin matrix for both composites consists of an adduct of urethane dimethacrylate and BIS-GMA. The filler particle in Heliomolar is agglomerated fumed silica measuring 0-04 [xm in diameter and loaded to 70% (by weight). In addition to approximately 1% fumed silica. Fulfil contains variably sized barium glass filler particles loaded to 78% (by weight). The mean diameter of the barium glass is 3 fxm, with a maximum value of 10 ^im. An almost equal distribution of Class I and Class II cavities was prepared in HI teeth, using 32 patients. Cavities were prepared for both amalgam and composite resin according to standard principles of modern operative dentistry consistent with conservation of tooth structure. Cavosurfaces of teeth to be restored with composite were neither bevelled nor modified specifically to accommodate the material. All restorations were randomly placed, although an attempt was made to match all materials within each patient by cavity classification and location within the arch. Forty-two Heliomolar, 38 Fulfil and 31 Dispersalloy restorations were placed by a single operator using rubber dam. Cavities restored with composite resins were lined with calcium hydroxide §. All enamel cavosurf aces were etched for 60s prior to restoration with the composite resin. After the placement of an intermediary resin, both composite materials were inserted into the cavity preparations and condensed. Surface layers were manipulated with a fine conical burnisher in order to draw the composite over the cavosurfaces as well as to develop a degree of anatomical form. After final polymerization, multifluted carbide burs were used for finishing. Patients were recalled 30 days postinsertion, at which time restorations were re-finished and baseline records obtained. A standardized questionnaire was completed by all patients in order to investigate retrospectively the nature of a high incidence of post-operative discomfort in teeth in which composite restorations had been placed. As the results of the questionnaire have not been reported previously, they are included in this paper. Assessment of all materials was made at baseline, and after 6, 12 and 24 months. Two dentists clinically evaluated all restorations by consensus using a modified USPHS system (Ryge 1980) (Table 1). Restorations were graded for anatomical form, marginal integrity and marginal leakage. No examination was made for colour match as this was not considered to be a significant attribute in assessment of the acceptability of a posterior composite resin. At the recall periods, each restoration was photographed. Impressions were taken using polyvinylsiloxane, and a double pour was made for documentation purposes and laboratory investigation by scanning electron microscopy (SEM). In this paper, the behaviour of a material is reported as a frequency of rating shift within a category rather than as numbers of restorations for each rating point. For the materials, descriptive statistics were used for each of the parameters assessed, and statistical significance was determined by Fisher's exact test. Significance for the * Vivadent AG, Schaan, Lichtenstein. 1L.D. Caulk, Milford, Delaware, U.S.A. IJohnson and Johnson, Brunswick, New Jersey, U.S.A. §Life-Kerr, Romulus, Michigan U.S.A.

Two posterior composite resins


Table 1. Modified USPHS criteria (Ryge, 1980) Category/rating

Wear Alpha









Restoration is continuous with existing anatomical form



Restoration is discontinuous with existing anatomical form, with no dentine or base being exposed


Sufficient material has been lost to expose dentine or base or to compromise restoration

Delta Marginal Integrity Alpha

Bravo Charlie Marginal discoloration Alpha

Restoration has fractured (bulk) or been lost Restoration appears closely adapted to tooth. No crevice is visible although explorer may detect minor unidirectional or single point two-direction catch Explorer catches in two directions and there is visible evidence of crevice. Dentine or base is not exposed Explorer penetrates crevice whose depth exposes dentine or base No marginal discoloration


Discoloration is present but has not penetrated in a pulpal direction


Discoloration has penetrated in a pulpal direction



patient questionnaire on post-operative sequelae was determined by the Chi-square test. Results

Analysis of the patient questionnaire indicated that 29% (32 of 111) of the teeth presented with some degree of sequelae after placement of the restorations. These were all restored with composites and were distributed between 19 individuals. Symptoms could be divided into three groups: those suggestive of (a) pulpal involvement, (b) occlusal dicrepancies, and (c) those for which a cross-over of symptoms masked a clear source of the sequelae. The results of these groupings by material are presented in Table 2. Statistical analysis of the data (total number of cases by material) indicated that the higher incidence of post-operative involvement for Heliomolar was significant at P=0-0152. It should be noted that intra-class correlations were not made for this analysis, as the level of significance was high. Most symptoms subsided spontaneously or by occlusal adjustments of the restoration. However, one tooth in two individual patients, each restored with Heliomolar, continued to present with persistent sensitivity associated with occlusal loading over a 10-week period, despite careful occlusal adjustment. Consequently, one restoration was completely replaced and the second was partially replaced with reinforced zinc oxide and eugenol in the centric contact area. Relief of symptoms was immediate in both cases. Eighty-five per cent of restorations were available for examination at the 2-year


/. Stangel and R. Y. Barolet

Table 2. Distribution of post-operative sequelae by symptoms Material Heliomolar Fulfil






41 39

9 5

1 1

12 4

22* 10*

•Differences significant at P = 0-0152. Table 3. Distribution of restorations at 2-year-recall Material


Heliomolar Fulfil Dispersalloy

37 32

recall, with the balance being lost to patient attrition. The distribution remained proportional to the number of restorations placed at baseline (Table 3). It is of interest that, despite the high rate of post-operative involvement at the time of insertion, no pain or sensitivity was present in any teeth containing composites at this time, as determined by standardized questioning of patients. This was consistent with the results from previous recall periods. After 2 years, 97-3% of Heliomolar, 93-8% of Fulfil and 100% of amalgam restorations were in the acceptable (alpha or bravo) category (Fig. 1). Analysis for significance revealed no differences in percentage acceptability between materials. However, a number of shifts had occurred for each of the materials within individual categories. The frequency of shift from alpha to bravo in one or more criteria per 150 135 o






Bravo Alpha 97 3









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30 15 0 Heliomolar




Fig. 1. Percentage of acceptable restorations after 2 years for each of the composites and amalgan. Alpha to bravo shifts within materials are indicated.

Two posterior composite resins


tooth was 48-6% for Heliomolar (18 of 37 teeth). One restoration (2-7% ) shifted to the Charlie category. For Fulfil, the frequency of alpha to bravo shifts was 25% (8 of 32 teeth), with one restoration shifting to char lie and one to delta (3-1% each). Dispersalloy demonstrated a frequency of alpha to bravo shift in 16% of restorations (4 of 25 teeth).

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The analyses of rating shifts by individual category for all three materials are shown in Fig. 2. The frequency of alpha to bravo shift for wear was 27% (9 of 37) for Heliomolar, and 21-9% (7 of 32) for Fulfil, while no perceptible wear was detected for Dispersalloy. One Fulfil restoration (3-1%) was rated charlie for excessive wear. When examined for significance, there were no differences in the rate of wear between the two composites. However, when comparing each of the posterior composites with amalgam, significant differences in wear were evident at F

Clinical evaluation of two posterior composite resins: two-year results.

Two composite resins were evaluated for clinical acceptability as restorative materials in Class I and II cavities over a 2-year-period. In addition, ...
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