Fracture Strength & Color Stability of Direct Composite Veneers Using Different Materials PDF

Fracture strength and color stability of … Vol.:18 No.1: 15/10/2022 MDJ Fracture strength and color stability of direct composite veneer using different materials ―Mohammed Hamoudi Alsunboli B.D.S HDD M.SC ― Assistant lecture...

Fracture strength and color stability of … Vol.:18 No.1: 15/10/2022 MDJ Fracture strength and color stability of direct composite veneer using different materials ―Mohammed Hamoudi Alsunboli B.D.S HDD M.SC ― Assistant lecture at College of Dentistry, AL-BAYAN University, Baghdad, Iraq , conservative department E-mail: [email protected] phone: 07901641590 ―Haider Hasan Jasim M.Sc ‖ Assistant professor at college of dentistry , Al.Mustansiria University , Baghdad, Iraq, conservative department E-mail : [email protected] phone: 07709613641 Abstract Aim: The purpose of this study was to compare the fracture resistance and color stability of three different restoration materials: Nano composite, flowable composite, and Nanohybid composite. Materials and Methods: 45 removed human maxillary premolar teeth for orthodontic treatment were chosen. The teeth were divided into three experimental groups, each consisting of fifteen teeth: Direct composite veneers constructed of Nano - composites were employed to fix the teeth in Group A. (Z350 XT, 3M, USA). Group B: Flowable composite was used to directly veneer teeth (G-aenial Universal flo GC, Japan). Group C: Direct composite veneers made of Nanohybid composite were used to reconstruct teeth (G-aenial GC, Japan). Each tooth in groups A, B, and C had a copyplast template made prior to preparation using a 1 mm thick vacuum-pressed polyethylene plastic template. Standard preparations (intra enamel) were made for all teeth in experimental groups using ceramic veneer set burs. By injecting flowable composite via a hole formed in a copyplast template, Group B is restored. In Groups A and C, the buccal third (Bucco-palatally) of the template was filled with restorative material using a plastic tool before being positioned on the tooth and squeezed until it made contact with the unprepared tooth surface. All specimens' baseline colors were assessed using a spectrophotometer (Vita Easyshade, Ivoclar VivadentAG, Schaan, Liechtenstin). After baseline color measurement, each group of laminate veneers were subjected to immersion solutions (Tea bags, Lipton). Each specimen's color values were once again measured with the same spectrophotometer, 135 MDJ Fracture strength and color stability of …. Vol.:18 No.1:15/10/ 2022 and the color change values (ΔE) were computed. Using a universal testing equipment, the fracture strength was evaluated. Results: The ANOVA test showed significant differences in color stability between the test groups (p 0.001). LSD demonstrated a substantial difference between Groups C and A. Likewise, there was a significant difference between Groups C and B (p0.001), but not between Groups A and B (p>0.05). When it came to the mechanical testing, the ANOVA test showed a significant difference in the groups' fracture strengths (p 0.001). The LSD test found a non-significant difference between Group B and C (p>0.05), but a significant difference between Group A and C, Group B and C, and Group C and Group B (p0.001). Conclusion: All types of composite materials used for veneers in the premolar region for patients with typical biting force may be regarded as safe. Nano-hybrid composite, which was used to rebuild teeth, has the best characteristics in terms of color stability and fracture strength, followed by flowable composite. Key words: Direct veneer and composite veneer. Color stability, fracture resistance INTRODUCTION laminates. Direct composite laminate veneers for the treatment of both anterior and posterior A composite veneer is one of the techniques teeth offer exceptional esthetic potential and for reestablishing the bio-aesthetic adequate lifespan at a significantly lower cost relationship. Fracture or de-bonding is the than analogous ceramic restorations. They may most frequent failure mode connected with be applied in a single session and are less laminated veneers in terms of inadequacy. expensive than indirect solutions. (59) Fractures accounted for 67% of all repair Ceramics are still the preferred esthetic failures after fifteen years of clinical alternative for many physicians, but they still performance. Additionally, it has been shown have a limited lifespan due to their that factors such as laminate veneer material, susceptibility to staining, wear, and preparation design, mechanical thermal surrounding cracks, which reduces the cycling, and tooth position affect how quickly esthetical outcome over time. (23) laminate veneers break, even if its long-term Composite restorations have increasingly performance is mostly controlled by the being used in dentistry for both anterior and amount and direction of the load. (5) There posterior restorative treatment, therefore, was no evidence to support the claim that dental composite materials should have many indirect laminates are superior to direct 136 MDJ Fracture strength and color stability of …. Vol.:18 No.1:15/10/ 2022 requirements that meet the clinical setting. Additionally, it has been demonstrated that the Anterior composite restorations must have the brand and color of the restorative material, same optical qualities as natural teeth, exposure time, the intensity of various food including color, metamerism, opalescence, and consumption, and finishing processes all affect fluorescence, in order to satisfy both the color stability. (52) dentist and the patient's aesthetic needs. (20) Colorimeters and spectrophotometers have Several studies have been conducted to become commonplace for detecting color evaluate the color stability of composite changes because color stability was one of the restorations because composite resins might requirements for aesthetic materials. change color over time. (51) When exposed to (47)Several research revealed that tea has the different media, such as tea, coffee, coca-cola, highest rate of color stability alterations (`17) chlorohexidine, or bleaching agent, Various studies have shown that coffee has the discoloration may develop over time.. There biggest influence on color changes. (18) are both intrinsic and extrinsic causes that The aim is to compare the fracture resistance might cause composite restorations to stain. and colour stability of direct veneer restored Extrinsic aspects entail adsorption or with three different composite materials, absorption of stains from the mouth cavity, Nanofill composite (Z350 XT, 3M, USA), whereas intrinsic factors include differences Nanohybrid composite (G-aenial anterior, GC, within the substance itself. One of the issues Japan), and flowable composite (G-anial that affects extrinsic staining is the universal Flo GC , Japan). restoration's softness on the surface. (51) MATERIALS AND METHODS teeth then placed in 0.1% thymol solution for 48 hour (30). The teeth were mounted into A total of 45 healthy human first premolars customized rubber mold (25 mm height × 20 from the maxilla that had been removed for mm × 20 mm) using cold cure acrylic (Vertex, orthodontic treatment were chosen. These Netherlands). The long axis of the tooth is set teeth had normal occlusal anatomy without to be parallel to the center of the mold with the attrition, comparable crown dimensions, (7-8 aid of the analyzing rod of the dental surveyor mm; mesio-distally and 8.5-10 mm occluso- (Jelenko Dental Surveyor, Dentarium, cervically). All teeth were visually inspected Germany). Three experimental groups were with blue light transillumination to make sure randomly assigned to three sets of teeth. (n=15 the enamel was free of cracks, and those that sample each) to receive direct composite did not were not included in the study. The 137 MDJ Fracture strength and color stability of …. Vol.:18 No.1:15/10/ 2022 veneer using one of the following materials: to paint the preparation's outline (Fig.3). Group A: were Nano composite (Z350 XT, Utilizing veneer system preparation burs, 3M, USA). Group B: flowable composite (G- uniform preparations (partial wrap) were made aenial Universal flo GC, Japan). Group C: for all the teeth (CVS for porcelain veneers, Nanohybrid Composite (G-aenial GC, Japan). Komet, Germany). In comparison to the middle and occlusal thirds, the cervical third of In all test groups, a clear copyplastic 1 mm the face shrank by 0.4 mm and 0.5 mm, template was created for each tooth respectively. (12) The preparation was independently utilizing a vacuum forming completed 1 mm occlusal to the junction of the machine (code 132, Biostar, Germany) and a 1 cement and enamel (24). 1.5 mm Bucco- mm thick vacuum pressed polyethylene plastic palatally and 1.5 mm occlusion-cervically template. The template was then taken out, and were removed from the buccal cusp. (53) Final the extra plastic was cut using a medical blade veneer preparation shown in (Fig.4). The and pair of scissors to create a coping for the preparation checked with previously made buccal and occlusal surfaces of each tooth. silicon index to determine amount of tooth (40). The cutting in Groups A and C adheres to reduction (Fig.5). However, Some dentin was the veneer design by 1 mm, which was painted frequently exposed, especially in the cervical before being used as a stopper during the tooth region. After testing the copyplast insertion of the composite. The template is template on the teeth, fluoride-free pumice then placed into the tooth, and the template's was used to polish the prepared tooth. edge is painted blue to serve as a guide while In Byaccordance with the manufacturer's placing the composite (Fig.2). In group B, a recommendations, the prepared tooth surface hole was cut in the template occlusally at the was then etched for 15 seconds using 35% cusp tip to enable the extrusion of extra phosphoric acid (ScotchbondTM Etchant, 3M composite materials (Fig. 1) (40) Before each ESPE, USA), rinsed for 10 seconds, and gently tooth was prepared, a sectional index was air dried for 5 seconds. A fully saturated brush made using a putty polyvinylsiloxane was used to apply two successive coats of substance (Prontosil, Italy) to assess the adhesive (AdperTM ScotchbondTM 1 XT, 3M consistency of tooth reduction. This sectional ESPE, USA) after drying. The adhesive was index may be formed over the original tooth. gently air-thinned for five seconds to allow for Using a surgical blade, the index was divided evaporation before being light-cured for ten from the Bucco-palatal direction for use in seconds using an LED curing light (D-LIGHT preparatory steps later on 28). Before DUO, Switzerland), as directed by the beginning, a waterproof color marker was used manufacturer. (1) In both B and C groups, 138 MDJ Fracture strength and color stability of …. Vol.:18 No.1:15/10/ 2022 following the checking of the copyplast stored in a distilled water for 24 hours in an template on the tooth, The customized incubator (Future Tech. Digital incubator, template was then placed on the tooth and f120, China) at 37˚C.. The baseline forced down until it made contact with the measurement of veneer color was done in the unprepared tooth surface in the buccal third same lightening conditions using the (Bucco-palatally) using a plastic instrument. spectrophotometer (Vita Easyshade, Ivoclar (Fig.6,7) The margin of the template should fit VivadentAG, Schaan, Liechtenstin) (38). The to blue line that was previously traced. This central region of the laminate veneer, which is would give an indication that the template was determined by the meeting point of four marks set in the correct position. In Group (B), after traced, was selected for the Vita Easy shade checking each copyplast template on the tooth, probe tip placement. (Fig.10). This was to put the flowable composite was first injected into tip in the same center position before and after the prepared tooth through a tiny aperture on aging during the measuring procedure. top of each template. Until the flowable composite was completely used up in the The spectrophotometer was recalibrated after template, this process was repeated. (Fig.8) color data collection of each sample. Each set The clear resin matrix was used to cure the of laminate veneers was subjected to tea resin composite for 40 seconds before the immersion solutions, which were created by template was removed. (Fig,9) The extra soaking a tea bag (Lipton, UAE) in 200 ml of polymerized resin composite was then boiling distilled water for one minute. The eliminated using blade number 12 and a probe tip of the calibration part was firmly diamond finishing burs. A 30-fluted tapered inserted into it, and it was kept there until a finishing bur was used to remove the incisal beep signaled that calibration was complete. composite sprue, and a tapered finishing The immersions were carried out twice daily diamond was used to smooth up the tooth- for ten minutes at room temperature for thirty resin composite interface. A tapered finishing days. After each immersion process, the diamond and finishing strips were used to veneers were washed with distilled water and smooth the proximal surfaces and curves. In then stored in artificial saliva at room group B, the surplus composite that had been temperature in the intervals between the extruded from the hole was removed, and the cycles. The immersion solutions were renewed composite was then light-cured for 20 seconds after each application. The samples then were using an LED curing lamp. Close to the tooth rinsed with distilled water for five minutes and on both the buccal and occlusal sides was the blotted dry with absorbent tissue paper before curative device. (1) All the specimens were the final color measurements. The same 139 MDJ Fracture strength and color stability of …. Vol.:18 No.1:15/10/ 2022 spectrophotometer was used to measure the A universal testing instrument (LARYEE color values of each specimen again, and the universal testing machine, China) was used to color change values (E) were calculated using conduct the fracture strength test. The the equation below. (49): crosshead speed for the load application was 0.5 mm/min. (3) with a specialized plunger (a ΔE= [(ΔL*)2+(Δa*)2+(Δb*)2]1/2. L steel rod with a flat end and 3.6 mm diameter) Lightness is denoted by *, and green-red by attached to the machine's upper moveable a*. and b* for blue-yellow. ΔL*, Δa*, Δb* compartment (28) and positioned at the occlusal portion of the laminate veneer (23). compare to the variations between the before- To the tooth's long axis, the load was applied and after-immersion cycles. For each at a 45-degree angle (8). Using a mounting jig specimen, each color measurement was made that was expressly created and made in the three times, and the average of the three area, this orientation stayed constant. readings was computed. The same operator Computer software automatically recorded the performed each color measurement technique. maximum force required to cause fracture for (49) in order to simulate the oral cavity each sample in Newtons (N). environment (artificial aging), thermal cycles were applied to all samples. These thermal RESULTS cycles could cause changes in the micro spaces 1. Fracture strength test between the tooth and the veneer due to the There were recorded 45 fracture strength presence of contraction and expansion stresses measures across all groups. For each group, caused by the different coefficients of thermal the computed minimum and maximum values expansion between the tooth structure and for the averages and standard deviations of restorative material.(22) An automatic fracture strength are shown in (Table 1-1). The thermocycling equipment was used to do the findings of this investigation showed that thermocycling. Two external water reservoirs Group C (189.53 N) had the highest mean connected to the cold and hot internal fracture strength, followed by Group B (1 8 2 reservoirs of a modified water coolant were N), and Group A had the lowest mean fracture part of the thermocycling system. The digital strength (162.67 N). thermostats on the heater and compressor help Further analyses of the mean difference in to regulate the temperature between 5° and 55° failure between every two groups were C. The device had a third water tank for conducted using the least significant test. The storing samples. (6). fracture strength of Group A was statistically 140 MDJ Fracture strength and color stability of …. Vol.:18 No.1:15/10/ 2022 significantly different from Groups B and C (p to within 1mm of its outline. To allow the 0.05) according to the LSD test results, extrusion of extra composite materials in although there was no difference between groups A and C as well as the injection of Group B and Group C. (table 1-2) flowable composite in group B, prepare an 2.Color stability test occlusal hole in the copyplast template's cusp A total of 45 measurements of color stability tip position. (40) for all groups were recorded. For each group, To achieve precise tooth reduction, several the estimated means and standard deviations of number of approaches have been planned, color change with lowest and maximum values such as Silicone matrices and depth-limiting are shown in (Table 1-3). According to the burs. (13) All teeth had uniform buccal study's findings, group A had the largest mean reduction utilizing cutter depth burs (Ceramic color change (10.10), followed by group B Veneer Set, Komet, Germany). Equal (9.20), and group C(5.73). had the lowest preparations of approximately 0.4 mm and 0.5 mean color change value (0.02). mm in depth were done in the cervical region According to the results of the LSD test, and the occlusal two-thirds, respectively, to Group C's color stability differed significantly make sure that the preparation was only (p 0.05) from Groups A and B while Groups A performed on enamel. (21) The and B exhibited no significant variation. cuspal reduction was occasionally used in the (Table 1-4). preparation. Comparing laminate veneers to teeth without cuspal reduction, it has been DISCUSSION found that these two dimensions—1.5 mm Only human maxillary premolars were used in occluso-cervical and 1.5 mm from the tip of this study in order to reduce size variation, and the cusp palatally—display improved teeth that experienced size changes were not mechanical performance (lower stress included. In order to apply a copyplast concentration) (8). template to all of the experimental teeth, a In this study, the fracture resistance test was primary imprint and primary model were used because it is one of the main reasons made, and they were afterwards removed. veneers fail. The mean fracture load for Group After surgically removing the extra material, a C (restored with nanohybrid composite) was plastic coping was then made for each tooth's the greatest. This was associated with the labial and occlusal surfaces. The veneer increased mechanical qualities since filler pattern, which was painted to act as a stopper weight and volume percentages were high during the insertion of the composite, was cut (76% and 72%, respectively) (11) , Additionally, the mixture of nano- and micro- 141 MDJ Fracture strength and color stability of …. Vol.:18 No.1:15/10/ 2022 hybrid particles may be another factor in group groups B and C in terms of fracture resistance. C's increased fracture resistance. Large, Test for color stability: A key aesthetic factor agglomerated nanoclusters supporting tiny, for tooth-colored restorations is color stability. tightly packed nanoparticles in this form of (4) Numerous research has given a lot of the composite increased its compressive attention to veneers' susceptibility to strength, fracture resistance, wear resistance, discoloration (39). It has become standard and surface hardness. (45) Group B (which practice to assess such discoloration using was restored with flowable composite) had the colorimeters and spectrophotometers, such as second-highest mean fracture strength. This Advance simple shade (58). Tea was chosen form of composite has the most adaptation to for the study's immersion solutions because it the tooth structure and poses the least risk of was thought to be a popular beverage. pulling back, hence reducing voids at the Comparing the certified materials' stain- edges. (7) In addition, compared to group A, resistance after 30 cycles of tea soaking was which was restored with nano the research's secondary purpose. The filled composite, the presence of 200-nm immersion cycles were made to last 10 strontium glass fillers that were distributed minutes twice day for 30 days in an effort to uniformly may be associated with an increase mimic the momentary contact of laminate in flexural strength and wear resistance. The veneers with tea before being washed away by composite's enhanced fluidity assures quick saliva. Between immersion cycles, the samples insertion with less stress, forming continuity were preserved in fake saliva to mimic the between tooth surfaces, adhesive, and neutralizing effect of saliva. (49) The Group C restorative material, allowing the resin to restorations with direct nanohybrid composite penetrate enamel even with minute defects, veneers displayed the best color stability. This and forming a single body between the might be because the ratio of filler to resin restoration and tooth structure(44). Group A, matrix changed from 55.6% to 44.4% in group which had its fracture resistance reduced to the A to 62% to 38% in group C. As a result, lowest level, was repaired using a nano-filled Group C, which is in charge of fluid composite; this could be related to the absorption leading to hydrolysis of the composition and microstructure of the interface between resin and filler, had a lower materials. Additionally, the composite resin percentage. The latter procedure may included poorly performing mono-dispersed cause the fillers, which significantly nanoparticles that are exclusively found in contributed to the color shift, to separate. ( 31) nanometric particles. There may not have been Another factor could be the different types of a statistically significant difference between resin. A hydrophobic monomer, UDMA, was 142 MDJ Fracture strength and color stability of …. Vol.:18 No.1:15/10/ 2022 thought to be more stain-resistant, whereas nanohybrid composite demonstrated higher TGDMA exhibits some water absorption, mean fracture resistance with a statistically allowing the entrance of a hydrophilic colorant significant difference compared to direct into the resin matrix and resulting in increased nanofiller composite veneers and a non- discoloration (50). The poorest stain-resistant significant difference compared to direct monomer according to BIS-GMA verification veneer with flowable composite. 3. In terms of (36). This was consistent with the study's fracture strength, flowable composite and findings, which revealed that group A, which direct veneer with nanohybrid are the best contains BIS-GMA, displayed the least veneering techniques 4. Direct veneer with amount of color stability among the C and B flowable composite showed significant groups. As both groups C and B contain the difference in fracture resistance in comparison same type of resin, being BIS-GMA free, this to direct nanofill composite veneers. 5. Direct hypothesis might also help to explain the fact veneer with nanohybrid composite that there was a difference in color stability demonstrated a greater mean color stability between the two groups. Because group C with a difference that is statistically different contains more resin (50%) than group B from nanofill composite and flowable (38%), the increase in color stability there may composite 6. Direct veneer with nanohybrid is be a result of this. (2). This is consistent with the veneering method that offers the best color Bagher's finding that raising the TEGDMA stability. fraction from 0% to 1% enhanced the water absorption of BIS-GMA-based based resin by References 3-6%. (9) In Group C, which had the lowest (1)bdul Khaliq, A. G., and I. I. Al-Rawi. color stability value, we, therefore, anticipate a Fracture strength of laminate veneers using rise in the amount of BIS-GMA. different restorative materials and techniques (A comparative in vitro stuy) (2014).. Journal Conclusions of Baghdad College of Dentistry. 26:1-8 The following results were reached within the (2)Acar O, Yilmaz B, Altintas SH, Chandrasekaran constraints of this in vitro study: 1. All of the I, Johnston W. Color stability of CAD/CAM and veneer types used in this study are suitable as a nanocomposite resin materials. (2016) J Prosthet maxillary premolar treatment for patients with Dent; 115: 71-75. normal biting force. The use of laminate (3)Akoglu, B., and D. Gemalmaz.. Fracture veneer in patient with parafunction should be resistance of ceramic veneers with different carefully evaluated. 2. Direct veneer with preparation designs. Journal of prosthodontics 143 MDJ Fracture strength and color stability of …. 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Minimum Maximum Mean Std. Deviation Group A 15 132 188 162.67 17.58 (Nanofill composite veneer) Group B 15 146 213 182.00 19.18 (flowable composite veneer) Group C 15 156 217 189.53 19.48 (Nanohybrid composite veneer) 45 178.07 21.61 Table (1-2): LSD Multiple Comparisons (least significant test) (I)Group (J) Group Mean Difference (I-J) Error Std. Sig. GroupA GroupB -19.3333-* 6.8520 0.007 GroupC -26.8667-* 6.8520 >0.001 GroupB GroupA 19.3333* 6.8520 0.007 GroupC -7.5333- 6.8520 0.278 GroupC GroupA 26.8667* 6.8520