UAB School of Dentistry

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1 Wear of a Calcium, Phosphate and Fluoride Releasing Restorative Material Final report -- August 18, 2014 UAB School of Dentistry John Burgess, D.D.S., M.S. Assistant Dean for Clinical Research University of Alabama in Birmingham SDB 602, rd Ave S Birmingham, AL Telephone FAX JBurgess@UAB.edu

2 Title of Project: Wear of a calcium, phosphate and fluoride releasing restorative material Objective: The aim of this study is to measure and compare the in vitro wear of a calcium, phosphate and fluoride releasing restorative material using the Alabama wear tester and 3D optical scanning to other clinically successful dental restorative materials. Introduction and Review of Literature: Dental composites have widely replaced amalgam as the choice of restorative material for posterior regions. 1 Posterior resin composite has been used and investigated as one of the most promising substitutes as a direct restorative system. 2 Various types of posterior resin composites have been developed and are commercially available. 3 These composites show improved clinical performances including wear resistance as reported by various clinical studies. 4-8 Table 1 -- Annual Failure Rates of Posterior Composite Restorations Author, year Evaluation Years Materials Tested Restorative Type Annual Failure Rate Failure Pallesen and Qvist, 2003 [25] 11 years Composite Medium to large Class II AFR 1.25% Tooth type Turkun et al., 2003 [76], 7 years Composite Class I and II AFR: 0.82% None van Nieuwenhuysen et al., 2003 [ yrs Amalgam, Composite, Crown Post -large Survival time: 7.8 yrs Tooth type, extension, vitality base, pt. age Busato et al., 2001 [109] 6 yrs Composite Class I and II AFR 2.5% Gaengler et al., 2001 [31] 10 years Composite + GI Class I and II AFR 2.6% _

3 Kohler et al., 2000 [51] 5 years Composite Class II AFR 5.5% Caries Risk van Dijken, 2000 [110] 11 Years Composite + Inlay Class II ARF 2.5 %direct Tooth type Wassel et al., 2000 [111] 5 years, P Composite Dir & Inlay Class I & II AFR 1.5% N/A Lundin and Koch, 1999 [112] 5 & 10 yrs Composite Class I & II AFR 2% & 2.1% N/A Raskin et al., 1999 [41] 10 yrs Composite Class I & II AFR 8.6% N/A Wilder et al., 1999 [113] 17 yrs Composite Class I & II AFR 1.4% N/A Collins et al., 1998 [73] 8 yrs Composite vs. Amalgam Class I & II AFR 1.7% N/A Mair, 1998 (74) 10 yrs Composite Class II 100% success N/A

4 While the wear resistance of dental composite restoratives is no longer considered to be a major concern for most restorations, the relatively limited information available suggests that it may still be a concern for very large restorations in direct occlusal contact, or for those patients with bruxing and clenching behavior Also, it is directly correlated with other mechanical properties which are the main reasons for intraoral fracture and failure of composites, such as fracture toughness, fatigue resistance, flexural strength and hardness Thus, the assessment of wear in clinical studies, the prediction of wear for new materials based on in vitro test methods, and the refinement of methods for quantitating wear remain as important concerns for dental researchers. The properties of dental composites depend on the type of resins used, filler content, particle size and distribution of the filler, and the degree of cure and ageing Under clinical conditions wear of the restorations is often classified into two types: contact wear caused by the contact of tooth to the restoration and non-contact wear due to food particles caught in between occlusal surfaces. 13 Condon and Ferracane noted that antagonistic enamel wear was the greatest for the composites containing the largest filler particle sizes. 14 Another study showed that harder filler particles (e.g. quartz) produced greater wear on the antagonist enamel compared to composites with softer filler particles (e.g. Ba-silicate). 15 The American Dental Association (ADA) has developed a guideline for acceptable wear rates for posterior resin composites. According to the current ADA criterion, the wear rate of posterior resin composites should be < 50 um by means of a specific simulated 3-year wear test. 18 Bulk placed and cured composites require fewer placement steps than incrementally placed composites. Compared to flowable bulk filled composites, the filler load with high viscosity composite is higher to improve their mechanical properties. 19 The aim of this study is to wear test a calcium, fluoride and phosphate releasing restorative material and compare it with two clinically successful composites, and one glass ionomer restorative material against an enamel antagonist. Null Hypothesis: The Activa restorative material has the same contact wear as the other three commercially available resins against enamel antagonist.

5 Materials: Table 2. Name and Type of Material Manufacturer Name and Address Shade Lot No. Expiration Date Curing Time ACTIVA Bioactive- Restorative Pulpdent Corporation 80 Oakland Street Watertown, MA A / sec Glass ionomer restorative material Fuji IX, GC America Inc.,3737 W 127th St, Alsip, IL A / sec Filtek Supreme Ultra Universal 3M ESPE 3M Center, Building SE-03 St. Paul, MN A2 N / sec Tetric Evo Ceram Ivoclar Vivadent Inc.,175 Pineview Dr, Amherst, NY A2 T / sec

6 Methods: Eight flat discoid specimens (Diameter = 15 mm, Height = 3 mm) were prepared for each resin, using a flexible elastomeric mold (Fig 1). The material was placed in one increment and cured through a glass slide placed on the composite to create a flat surface. The curing time recommended by each manufacturer (20 sec) was applied using an Elipar S10 (3M ESPE). After fabrication the specimens were stored in distilled water at 37ºC in an incubator for 24hours. The composite specimens were mounted in brass holders (d=15mm) using self-curing acrylic material (Flash Acrylic by Yates and Bird) (Fig 3). The specimens were wet ground to a flat surface with a series of SiC abrasive paper (320-, 600-, 1200-grit) and water spray for 1 minute each using a rotational polishing device (No: , Buehler Ltd, Evanston, IL, USA). A final finish with 0.05µ alumina slurry and a polishing cloth was applied (Fig 4). After polishing, the specimens were sonicated for 5 minutes (Branson 1200) to remove polishing debris. Figure 1. Composite Build-up Figure 2. Light Curing composite specimen through a glass matrix Figure 3. Specimen secured in brass holder Figure 4. Polishing

7 Enamel Styli Preparation: Cusp shape on freshly extracted mandibular premolars was standardized using a cone shaped diamond bur (Brasseler, USA) in a straight handpiece (Fig 5, NSK, Japan). The enamel cusp tip was unaltered (Fig 6), which allowed the fluoride rich enamel layer of the tooth to remain. This maintained the maximum tooth hardness. The standardized cusp was used as the antagonist for wearing the opposing restorative material by mounting the teeth onto a metal styli and stabilizing them with self -cure acrylic. The complete enamel cusp was scanned using the Proscan 2000 before and after wear testing (Fig 7). Figure 5: Standardization of the enamel cusp Figure 6: Occlusal View of standardized cusp Figure 7: Proform View WEAR TESTING: The specimens were placed in the modified UAB wear testing machine. (Fig 8). The fluid circulated was a 1:3 mixture of glycerol and water with the same viscosity as natural saliva. The solution was stirred and pumped through the wear machine so that each specimen was constantly covered with the mixture. A 20 N load was applied by the enamel styli to the flat restorative surfaces positioned on a 2mm horizontal sliding platform which provided a lateral

8 sliding wear motion similar to teeth functioning in the oral cavity. These enamel styli contacted the lower flat specimens with a frequency of 50cycles/min for 100,000 cycles. Figure 8. Modified UAB Wear Testing Device SCANNING: The composite and the enamel styli were scanned using a non-contact 3D surface measurement instrument PROSCAN 2000 (Scantron Industrial Products Ltd. Taunton, England). (Fig 9) The volumetric wear and wear depth of each material was determined with ProForm software (Scantron Industrial Products Ltd.Taunton, England). Fig 9.Proscan 2000 Non-Contact Surface Profilometer

9 Figure 10. Wear of Four Restorative Materials mm3 1,2 1 0,8 0,6 0,4 0,2 0 Fuji IX Activa Tetric Filtek Supreme Results: Data is show in tables 3, 4, and 5. Table 3: Wear of a RMGI restorative and ACTIVIA Materials Glass Ionomer Restorative ACTIVA Restorative Specimen Wear Enamel Wear Specimen Wear Enamel Wear S. No Mean±SD 1.05 ± ± ± ± 0.3

10 Table 4: Wear of two clinically successful composites and the opposing enamel stylus. Materials Tetric Evo Ceram Filtek Supreme Ultra Specimen Wear Enamel Wear Specimen Wear Enamel Wear S. No Mean±SD 0.05 ± ± ± ± 0.2 The enamel to enamel data in table 5 is used as a control to show the enamel tooth wear when enamel functions against enamel with the same number of wear cycles. When the enamel to enamel wear is compared to enamel wear produced by the restorative materials the enamel to enamel wear is significantly greater than that produced by the restorative material to enamel. So enamel to enamel wear has a mean volume loss of 1.06mm 3 while the maximum volume wear produced by the restorative material to enamel is 0.7mm 3. Discussion: All data is shown (Table 3 and 4) however we repeated a number of specimens due to porosity especially in the glass ionomer restorative material specimens. Generally, wear volume loss is the more accurate value and is what we normally report for journal submission. All the data was sent to you to be complete. As you can see (Table 5), the wear volume of ACTIVA against enamel is very good comparing favorably with clinically successful dental restorative composite resins.

11 Table 5: Wear Produced by Cycling an Enamel Cusp Tip Against a Flat Enamel Disk. Materials Enamel Control Enamel Wear S. No Mean±SD 1.06 ± 0.2 Data Analysis: ANOVA and Tukey tests were used to determine intergroup differences (p=.05). Fuji IX, a glass ionomer restorative material produced significantly great volume wear than all other dental restorative materials (p<.05). No significant difference in wear volume was produced with any of the dental composite resin restorative materials (p>.05).activa had wear volume loss that was statistically similar to clinically successful dental restorative materials. In addition, ACTIVA produced little wear on the opposing enamel- it did not wear more than other successful restorative dental composite resins. As a control, the wear produced by the restorative material on the opposing enamel is compared to enamel to enamel wear. As you can see (table 3), three dental restorative materials (ACTIVA, Filtek Supreme Ultra and Tetric EvoCeram) wore less than the enamel to enamel control, and one (Fuji IX glass ionomer restorative material) wore the same as the enamel to enamel control. The enamel to enamel control gives an idea of the wear of natural tooth vs natural tooth wear. Conclusions: 1. The Fuji IX glass ionomer restorative materials produced significantly greater wear than all other materials (p<.05). 2. Activa, Filtek Supreme Ultra and Tertric EvoCeram produced wear that was statistically the same (p>.05). 3. The ACTIVA restorative material should be wear resistant enough to be placed in occlusal load bearing areas successfully.

12 References: 1. Shiro Suzuki, DDS, PHD, Does the Wear Resistance of Packable Composite Equal that of Dental Amalgam?. ( J Esthet Restor Dent 16: , 2004) 2. Leinfelder KF. A conservative approach to placing posterior composite resin restorations. J Am Dent Assoc 1996; 127: Fortin D, Vargas MA. The spectrum ofcomposites: new techniques and materials. J Am Dent Assoc 2000; 131: Heymann HO, Leonard RH, Wilder AD, Sturdevant JR, Leinfelder KF. Five-year clinical study of composite resins in posterior teeth. J Dent Res 1987; 66:166. (Abstr) 5. Lundin SA, Andersson B, Koch G, Rasmusson CG. Class II composite resin restorations: a three-year clinical study of six different posterior composites. Swed Dent J 1990; 14: Perry RD, Kugel G, Habib CM, McGarry P, Settembrini L. A two-year clinical evaluation of TPH for restoration of Class II carious lesions in permanent teeth. Gen Dent 1997; 45: Gaengler P, Hoyer I, Montag R. Clinical evaluation of posterior composite restorations: the 10-year report. J Adhes Dent 2001; 3: Busato AL, Loguercio AD, Reis A, de Oliveira Carrilho MR. Clinical evaluation of posterior composite restorations: 6-year results. Am J Dent 2001; 14: J.W.V. Van Dijken (2000) Direct resin composite inlays/onlays: an 11 year follow-up. Journal of Dentistry, 28 pp K.J. Soderholm, P. Lambrechts, D. Sarrett, Y. Abe, M.C. Yang, R. Labella et al. (2001) Clinical wear performance of eight experimental dental composites over three years determined by two measuring methods European Journal of Oral Sciences, 109 pp Condon JR, Ferracane JL. In vitro wear of composite with varied cure, filler level, and filler treatment. J Dent Res 1997;76: Indrani DJ, Cook WD, Televantos F, Tyas MJ, Harcourt JK. Fracture toughness of wateraged resin composite restorative materials. Dent Mater 1995;11: Bloem TJ, McDowell GC, Lang BR, Powers JM. In vivo wear. Part II: Wear and abrasion of composite restorative materials. J Prosthet Dent 1988;60: Condon JR, Ferracane JL. Evaluation of composite wear with a new multi-mode oral wear simulator. Dent Mater 1996;12: Suzuki S, Suzuki SH, Cox CF. Evaluating the antagonistic wear of restorative materials when placed against human enamel. J Am Dent Assoc 1996;127: A. Peutzfeldt, E. Asmussen (1992) Modulus of resilience as predictor for clinical wear of restorative resins Dental Materials, 8 pp J.L. Ferracane, J.R. Condon, J.C. Mitchem (1997) Correlating abrasive wear to mechanical properties of experimental dental composites Transactions of the Academy of Dental Materials A ADA Council on Scientific Affairs. Acceptance program guidelines for resin based composites for posterior restorations. Chicago: ADA Publishing, Phillips RW (1996) Phillip s Science of Dental Materials, 10th edition, Philadelphia, PA: W.B Saunders Co. p 274.