Top PDF In-Vitro Evaluation of the Effect of Herbal Antioxidants on Shear Bond Strength of Composite Resin to Bleached Enamel

In-Vitro Evaluation of the Effect of Herbal Antioxidants on Shear Bond Strength of Composite Resin to Bleached Enamel

In-Vitro Evaluation of the Effect of Herbal Antioxidants on Shear Bond Strength of Composite Resin to Bleached Enamel

oxygen free radicals. The findings of our study showed equal antioxidant efficacy of grape seed and sodium ascorbate, which is in accord with the results of Vidhya et al, [4] and Sharafeddin et al, [23]. Two in-vitro studies demonstrated that grape seed extract inhibited the demineralization and enhanced the remineralization of carious root lesions [4,33]. The results of microscopic analysis confirmed the findings of shear bond strength testing in our study, since group 2 with the lowest bond strength value had the highest frequency of adhesive failure. In the current study, antioxidants were applied in the form of solution. Use of antioxidants in the form of hydrogel is recommended in future studies. In the current study, antioxidants were used for 10 minutes. Other studies are required to assess the effect of higher concentrations of antioxidants with shorter application times. Since antioxidants have a short shelf life, future studies are recommended to focus on the storage methods of antioxidants. The current study had an in-vitro design and clinical studies are needed to further elucidate this issue.
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The Effect of Aloe Vera, Pomegranate Peel, Grape Seed Extract, Green Tea, and Sodium Ascorbate as Antioxidants on the Shear Bond Strength of Composite Resin to Home-bleached Enamel

The Effect of Aloe Vera, Pomegranate Peel, Grape Seed Extract, Green Tea, and Sodium Ascorbate as Antioxidants on the Shear Bond Strength of Composite Resin to Home-bleached Enamel

In this experimental study, 60 recently extracted sound human maxillary incisors were collected and randomly divided into 6 groups (n=10). The tooth roots were em- bedded in cylindrical acrylic resin blocks (1.5×2.5 cm), with only the tooth coronal portion (above the ce- mentoenamel junction) out of the block. The labial enamel surfaces of samples (6×6 mm) were polished with silicon carbide paper of 600 grit size (Moyco Pre- cision Abrasives; Montgomeryville, PA, USA). The prepared labial surfaces of all the teeth were bleached with 15% carbamide peroxide gel (Opalescence; 15% PF, Ultradent Product Inc, South Jordan, UT, USA) for 6h/day for 5 days. After completion of daily bleaching procedures, the teeth were rinsed with water spray for 1 minute and then kept in distilled water at room tempera- ture until the next day.
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Effect of different anti oxidants on shear bond strength between nano hybrid composite and bleached enamel-an invitro study

Effect of different anti oxidants on shear bond strength between nano hybrid composite and bleached enamel-an invitro study

Fifty recently extracted human single rooted teeth were divided groups of 10 teeth each. In Group I (positive control), the composite bonding was Except Group V (negative control), the labial enamel in the other groups were bleached with 35% hydrogen peroxide composite restoration. Groups II, III, and IV specimens were treated with antioxidants 10% sodium ascorbate, 10% pine bark extract, 10%Aloe vera respectively, for 10 min and bonded with composite resin. All specimens were stored in deionized water for testing by using universal testing machine.The data and statistically analyzed using analysis of variance One way wed the highest shear bond strength followed by the bleached teeth treated with the antioxidant 10% Aloe vera.
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Effect of Three Different Antioxidants on Shear Bond Strength of Composites To Bleached Enamel - An In Vitro Study

Effect of Three Different Antioxidants on Shear Bond Strength of Composites To Bleached Enamel - An In Vitro Study

Perhydroxyl radicals are not only associated with high permeability and diffusibility but also split the long chained, dark colored macromolecules of pigments into smaller, less colored and more diffusible molecules which are removed from the structure producing the bleaching effect. Following bleaching, these free radicals react with the organic enamel and can result in morphological alterations, surface irregularities and reduced bond strength of composite resin to enamel.

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Aims: Residual peroxide on the enamel surface and in the interprismatic spaces decreases the shear bond strength (SBS) of composite to bleached enamel. Evidence shows that 10% sodium ascorbate can efficiently neutralize the singlet oxygen generated by the bleaching agents. This study aimed to assess the effect of duration of application of sodium ascorbate on SBS of composite to bleached enamel. Materials and Methods: This in vitro experimental study was conducted on 30 sound human third molars, which were randomly divided into three groups (n=10). In group 1, the teeth were bleached for 45 minutes and were then subjected to immediate bonding and restoration with composite resin. In groups 2 and 3, the teeth were bleached, immersed in 10% sodium ascorbate solution for 5 (group 2) and 10 (group 3) minutes and were then bonded and restored with composite, and the SBS was then measured. Results: The highest SBS (14.02±8.6MPa) was noted in group 3 (immersion in 10% sodium ascorbate for 10 minutes before bonding). The lowest SBS was noted in group 1 (immediate bonding after bleaching) (p<0.05). The difference in SBS of groups 1 and 2 was not significant (p=0.4). Conclusion: Application of 10% sodium ascorbate for 10 minutes increases the SBS of composite to bleached enamel.
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Evaluation of Shear Bond Strength of Methacrylate- and Silorane-based Composite Resin Bonded to Resin-Modified Glass-ionomer Containing Micro- and Nano-hydroxyapatite

Evaluation of Shear Bond Strength of Methacrylate- and Silorane-based Composite Resin Bonded to Resin-Modified Glass-ionomer Containing Micro- and Nano-hydroxyapatite

Several studies investigated the effect of adding different amounts and sizes of apatite powder to GIC for improving the physical property of this cement. [19-22] These studies demonstrated that GICs containing hy- droxyapatite exhibit better mechanical properties and higher bond strength to dentin than the conventional GICs. A study reported that hydroxyapatite-reinforced glass-ionomer, 75wt% of glass-ionomer and 25wt% of hydroxyapatite, exhibited the highest bond strength to dentin. [23] It has been demonstrated that adding nano- hydroxyapatite (nano-HA) to glass-ionomer shows higher bond strength to tooth structure compared to mi- cro-hydroxyapatite (micro-HA). The decreased size of nano-HA particles, similar to that of the minerals in tooth, leads to increased surface area and higher solubil- ity, filling the enamel defects with higher performance ;this phenomenon occurs through releasing calcium and phosphate ions and by increasing the bond strength be- tween the tooth and the restorative material. [24]
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Comparative evaluation of the shear bond strength between repair composite resin bonded to bilayered and monolithic ceramic restorations: An In Vitro study

Comparative evaluation of the shear bond strength between repair composite resin bonded to bilayered and monolithic ceramic restorations: An In Vitro study

Kato et al (2001) 39 determined the bond strengths of adhesive resins joined to a feldspathic porcelain (VMK 68). For this study they considered three porcelain surfaces-ground, air-abraded with alumina, and etched with hydrofluoric acid. And for priming agent a two-liquid porcelain conditioner that contained both 4-methacryloyloxyethyl trimellitate anhydride and a silane coupler (Porcelain Liner M) was used. In order to examine the effects of the respective chemical ingredients on adhesive bonding each of the two liquid components of the conditioner was also used individually. As for the luting agents two methyl methacrylate based resins initiated with tri-n-butylborane either with or without 4- META were used. Shear bond strengths both before and after thermocycling were determined. And the results indicated that thermocycling was effective for disclosing poor bonding systems. Etching with hydrofluoric acid followed by two-liquid priming with the Porcelain Liner M material generated the most durable bond strength.
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Evaluation of Shear Bond Strength of Four Commercially Available Resin Cements: In Vitro Study

Evaluation of Shear Bond Strength of Four Commercially Available Resin Cements: In Vitro Study

J.J. LINDEN et al (1991) 13 determine the effects of porcelain opacity, chemical catalyst, and exposure time on polymerization of light- activated resin-composite cements. Samples of microfill and hybrid composites, with and without catalyst (i.e., dual-cure and visible-light- activated), were polymerized by exposure to visible light through porcelain discs of different opacities. Micro hardness testing (KHN) was used to compare degree of cure for each material at various exposure times. Porcelain opacity did not significantly affect hardness. However, the results indicated that a chemical catalyst and prolonged curing times might be essential for clinical success.
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Effects of at-home and in-office bleaching on the shear bond  strength of metal, ceramic and composite brackets to enamel: An In vitro study

Effects of at-home and in-office bleaching on the shear bond strength of metal, ceramic and composite brackets to enamel: An In vitro study

Studies have examined the physical alteration after bleaching to find a possible explanation for decrease in enamel bond strength caused by bleaching agents. Titley KC et al also suggested that the reduction in bond strength might be related to the presence of residual hydrogen peroxide at or near the enamel surface which interfered with resin attachment and inhibited resin polymerization. (28) There are more studies that have described this effect. (29,85) The loss of calcium and alterations in the organic substance might be important factors to cause a decrease in enamel bond strengths. (37) Rotstein I et al suggested that bleaching agents changed the original ratio between the organic and inorganic components of the tissues and increased their solubility. (41) Also, Bistey T et al reported that at-home and in-office peroxide- containing bleaching agents are capable of causing structural alteration in enamel at low and high concentrations as well. (62) These studies probably explains the reduction in shear bond strength after office bleaching.
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Effect of waiting time for placing resin composite restorations after bleaching on enamel bond strength

Effect of waiting time for placing resin composite restorations after bleaching on enamel bond strength

This study investigated the influence of the waiting time for placing resin composite (RC) restorations after dental bleaching on the shear bond strength (SBS) to enamel. Seventy bovine incisors were obtained, of which 60 were stained in coffee solution for 1 week and then bleached with the whitening agent Lase Peroxide Sensy (DMC Equipments, Brazil), following the manufacturer directions of use. Next, all teeth were allocated into seven groups (n = 10) according to the waiting time after bleaching for placing the RC: immediately (0 h), 24 h, 3, 7, 14 and 28 days (d). Ten teeth were not bleached to serve as control. The specimens were prepared for SBS test and also for failure mode analysis. Scanning electron microscopy images were taken in non- bleached and bleached specimens. Data was analyzed by one-way ANOVA and Tukey’s test (α = 0.05). The SBS means (standard deviations), in MPa, were: control = 8.5 b (5.8);
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Comparative evaluation of the shear bond strength of the bond between ceramic and enamel pretreated with different etching methods: An In Vitro study

Comparative evaluation of the shear bond strength of the bond between ceramic and enamel pretreated with different etching methods: An In Vitro study

Resin based composite cements are the cements of choice for the adhesive luting of ceramic restorations. 6 Resin cements are capable of producing micromechanical attachment to the tooth structure. 20 Two types of resin cements available are dual-cured and light-cured resin cement. 27 Light- cured cements have some proven advantages in that working time is increased, the ability to remove excess cement is facilitated and this reduces the finishing time. 27 Dual-cured cements traditionally are used when ceramic thickness does not allow light penetration for maximal conversion of the luting cement. 30,43 Disadvantages of dual-cured cements include porosity from mixing, reduced working time, decreased degree of conversion and color instability due to amine degradation. 27 In accordance with the literature, the present in vitro study used a dual-cured resin cement for the bonding of ceramic blocks (5 x 5 mm) onto the surface treated tooth samples.
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Comparative evaluation of reversal of shear bond strength on bleached enamel using antioxidants – sodium ascorbate, salicylic acid & N-acetyl cysteine: An in vitro study

Comparative evaluation of reversal of shear bond strength on bleached enamel using antioxidants – sodium ascorbate, salicylic acid & N-acetyl cysteine: An in vitro study

20 Prevention (CDC) has adopted guidelines for infection control of extracted teeth used for research and teaching. These guidelines require that teeth not containing amalgam be heat-sterilized by an autoclave cycle for 40 minutes before use. Teeth that contain amalgam should be stored in 10 percent formalin for two weeks before use. Although autoclaving does not seem to alter the tooth's physical properties sufficiently for research purposes, it is unknown whether autoclaving affects the chemical and micromechanical relationship between dentin and dental. In this study, we investigated the effect of storage conditions and sterilization methods on the composite-to-dentin bond strength. Within the rotations of this study, we can draw the following conclusions. When storage solutions alone are compared, 0.9 percent NaCl and 5.25 percent NaClO resulted in significantly lower SBS values an those obtained with H 2 O 2 . Therefore,
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Effect of surface removal following bleaching on the bond strength of enamel

Effect of surface removal following bleaching on the bond strength of enamel

still not clear, the reduced bond strength of bleached enamel has been related to the presence of residual free radicals due to the breakdown of hydrogen peroxide [14, 18] and alter- ations in the enamel composition and structure [6, 19] fol- lowing the bleaching treatment. The residual oxygen in the interprismatic spaces can hamper resin infiltration and in- hibit resin polymerization [20]. Moreover, morphological and compositional changes (e.g., porosity, loss of enamel prismatic form, loss of calcium, and changes in organic sub- stances) in the enamel may weaken the adhesive interface and compromise bond strength [21, 22]. Therefore, bonding procedures should not be performed immediately after bleaching treatment [23]. A waiting period of 1–3 weeks has been advocated by various researchers [21, 24, 25]. In addition to the delayed bonding procedure, the application of antioxidant agents (e.g., sodium ascorbate, sodium bi- carbonate, and grape seed extract) [18, 26, 27] and laser ir- radiation [28, 29] have been proposed to restore the compromised bond strength of bleached enamel. By neu- tralizing residual free radicals [30] and promoting micro-retentions in the enamel surface [28], antioxidant agents and laser irradiation have been shown to reverse the reduced bond strength between the composite resin and bleached enamel. However, it is important to point out that most of the above-mentioned studies measured the bond strength without thermocycling [24–29]. Ther- mocycling is the in vitro process of subjecting a restor- ation and tooth to temperature limits similar to those experienced in the oral cavity [31]. It would be of interest to investigate the effects of thermocycling on the bond strength between the composite resins and the bleached enamel.
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Effect of Addition of Curcumin Nanoparticles on Antimicrobial Property and Shear Bond Strength of Orthodontic Composite to Bovine Enamel

Effect of Addition of Curcumin Nanoparticles on Antimicrobial Property and Shear Bond Strength of Orthodontic Composite to Bovine Enamel

count in all concentrations of curcNPs was significantly lower than that compared to the control group (plain composite) and reached zero (all P<0.001). However, S. mutans colony count was not significantly different among the three groups with 1%, 5% and 10% concentrations of curcNPs (all P>0.999). The colony count of S. sanguinis significantly decreased in all three concentrations of curcNPs compared to the control group (all P<0.001). Comparing the colony count in three groups with 1%, 5% and 10% concentrations of curcNPs revealed that colony count decreased with an increase in concentration of curcNPs; however, the differences were not statistically significant (all P>0.999). The colony count of L. acidophilus significantly decreased in all three concentrations of curcNPs compared to the control group (all P<0.001). However, L. acidophilus colony count was not significantly different among the three groups with 1%, 5% and 10% concentrations of curcNPs (P=0.968 for the comparison of 1% and 5%, P=0.884 for the comparison of 1% and 10% and P=0.992 for the comparison of 5% and 10%). Disc agar diffusion test results: In the agar diffusion test, no growth inhibition zone was noted around composite discs in any group. Eluted component test: Analysis of the results of eluted component test for assessment of bacterial proliferation at three different time points by two-way ANOVA revealed that the interaction effect of time and concentration was not significant for S. mutans (P=0.985), S. sanguinis
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Comparison of Bond Strength of Porcelain Laminate Veneers Bonded to Laser Treated Dentin and Acid Treated Dentin : An In Vitro Study

Comparison of Bond Strength of Porcelain Laminate Veneers Bonded to Laser Treated Dentin and Acid Treated Dentin : An In Vitro Study

Marco Franchi et al (1995) 9 st at ed that the best removal of dentinal smear l a yer res ult ed from the 37% phos phoric aci d t reatment; al l the dentinal tubul es ori fices appeared to be compl et el y opened. In this stud y t hree standard occlus al caviti es with bevel led enam el margins were prepared on each t oot h and et ched with the et ching s olutions of three denti nal adhesi ve s ys t ems; ( 1 ) 37% phos phori c acid s ol ution. (2) 4.3% ox alic acid and 2.6% aluminium salts solution, and (3) 10% mal ei c acid soluti on. Scanni ng elect ron micros copic anal ys is reveal ed that al l the et chi ng soluti ons affect ed the enam el s urface m orphology. The solut ion of oxal ic aci d and al umini um salts removed pri maril y the prism core m at eri al and parti all y the peripher y of the pr isms , but did not affect t he non bevell ed enamel surface. Phos phori c acid and m al ei c acid removed both prism core m at eri al s and prism peripher y; thes e specim ens al so showed areas in whi ch no pri sm morphology coul d be det ected. Thes e t wo acids also rem oved apatit e cr yst als from t he pri sm core of t he int act enamel surface.
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An in Vitro Comparison of Bonding Effectiveness of Different Adhesive Strategies on Erbium:Yttrium Alluminum Garnet Laser Irradiated Dentin

An in Vitro Comparison of Bonding Effectiveness of Different Adhesive Strategies on Erbium:Yttrium Alluminum Garnet Laser Irradiated Dentin

The bond strengths to lased tooth substrates reported in the literature are often confusing and even contradictory [1]. Some studies reported higher bond strengths to laser-conditioned dentine than to acid etched dentine [2], while others showed significantly lower bond strengths [3]-[5] or even no significant differences [6]. To date no recommendations have been provided for the use of adhesive systems on irradiated dentin, neither clear consen- sus has been reached on which material should be considered as the gold standard for this technique [7]. The op- timal etching strategy for laser-prepared dentine is controversial too. Different adhesive strategies are currently implemented in modern restorative dentistry including resin composite combined with etch and rinse adhesive systems or self-etch adhesive systems, glass-ionomer cement and self-adhesive resin composite. Many authors investigated the interaction between these systems and lased dentin. For the etch and rinse system, Er:YAG laser ablation creates a smear layer free dentin surface, but is not able to expose any dentin collagen fibres [8], that are required to the formation of hybrid layer. However, Er:YAG laser irradiation produces a laser-modified su- perficial layer with a peculiar morphological pattern in which collagen fibres are partially denatured, fused and/or melted, poorly attached to the underlying dentine substrate and have lost part of their cross-banding [9]. This amorphous collagen layer is completely devoid of interfibrillar spaces and probably restricts resin diffusion into the subsurface intertubular dentine, thus undermining the formation of an authentic, typical hybrid layer [9]. For self-etch adhesive system a decrease in bond strength to lased dentin was also demonstrated [10]. The poor efficacy of self-etching primers on laser-treated dentine could be attributed to the limited capacity of the acidic monomer to demineralize the laser-modified superficial layer and alter the resulting morphological pat- tern. According to previous studies [11], the degradation of organic dentine and the changes in size and ultra- structure of apatite crystals due to laser irradiation substantially increase the acid-resistance of lased dentine. Additionally, it has been reported [12] [13] that Er:YAG laser irradiation reduces the carbon-to phosphorus ratio and leads to the formation of more stable and less acid-soluble compounds, thus reducing the susceptibility of dentine to acid attack. Therefore, it seems feasible that an etchant agent with stronger acid potential, such as 35% phosphoric acid, would remove the laser-modified dentine layer more efficiently than an etchant agent with weaker acid potential, such as the acidic monomer in self-etching primers. However, many other studies have also found self-etch adhesives to be more effective than etch and rinse adhesives for dentine-ablated specimens [14]-[17].
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Effect of enamel protective agents on shear bond strength of orthodontic brackets

Effect of enamel protective agents on shear bond strength of orthodontic brackets

The lowest SBS was recorded with the samples treated with Clinpro before bonding the orthodontic brackets; the SBS in this group was significantly lower than the SBS in the other five groups. This could be attributed to the resistance effect that the outer enamel layer acquires from the fluoride content of the Clinpro which may be of significant effect especially when using self-etching primers in bonding due to their more superficial etching effect compared with the etching of the conventionally used phosphoric acid. Previous studies [28-30] with scanning electron microscope (SEM) indicated that although self- etch priming agents have the potential to etch the enamel surface, the etching pattern is less deep compared to the etching pattern of phosphoric acid. A chemical bonding capacity through the interaction between some functional monomers and the calcium of residual hydroxyapatite may contribute favorably to the bonding effectiveness [31-33], but fluoride affects the enamel surface rendering it more
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Effect of Different Surface Treatments on Microtensile Bond Strength of Composite Resin to Normal and Fluorotic  Enamel after Microabrasion

Effect of Different Surface Treatments on Microtensile Bond Strength of Composite Resin to Normal and Fluorotic Enamel after Microabrasion

After the bonding procedure, all samples were stored in tap water at 37 o C for 24 hours. The teeth were sectioned with a water-cooled slow-speed diamond saw (Isomet 1000; Buehler Ltd., Lake Bluff, IL, USA) perpendicular to the bonding surface in both x and y directions to obtain three rectangular resin-enamel sticks measuring 1×1mm 2 . The dimensions of the sticks were measured by means of a digital caliper (CD-15 S; Mitutoyo, Tokyo, Japan). The non-trimmed samples were fixed to modified Geraldeli µTBS testing jig [10] with cyanoacrylate glue (Model Repair II blue, Dentsply-Sankin, Tokyo, Japan) and loaded in the LRX testing machine (Lloyd, Hampshire, UK) with a 100N load cell and a crosshead speed of 1 mm/minute.
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Shear Bond Strength of Molar Tubes to Enamel Using an Orthodontic Resin-Modified Glass Ionomer Cement Modified with Amorphous Calcium Phosphate

Shear Bond Strength of Molar Tubes to Enamel Using an Orthodontic Resin-Modified Glass Ionomer Cement Modified with Amorphous Calcium Phosphate

with Fuji Ortho LC glass ionomer modified with ACP had borderline SBS for use in the clinical setting. However, a comparison of their study and ours is difficult since we used buccal tubes and Fuji Ortho LC glass ionomer instead of orthodontic bands and a conventional glass ionomer. Dandachli [38] reported a 15.7% rate of clinical bond failure when using RMGI cement for bonding of ceramic brackets to the enamel, which was higher than the 7% failure rate in the group bonded with Transbond XT. This finding was also confirmed in our study. Similar to the samples in group 2 of our study, the most common location of debonding of the tubes in the cited study was at the enamel-adhesive interface, which is attributed to the weak bond strength of the glass ionomer cement to the enamel [38].
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A Comparative Analysis of Shear Bond Strength of Composite and Acrylic Teeth to Heat-Cured Acrylic Resin by Difference Preparation Methods

A Comparative Analysis of Shear Bond Strength of Composite and Acrylic Teeth to Heat-Cured Acrylic Resin by Difference Preparation Methods

The findings of anterior teeth prepared by methylmethacrylate showed a significant difference between different artificial teeth, including phoenix, Emeral, crystal, ECL, and Ivoclar (p=0.004). Ivoclar, crystal, phoenix, Emeral, and ECL were found to have the maximum strength, respectively. The increased bond strength in acrylic teeth compared with composite artificial teeth might be due to increased polymerization at the ridge lap area while using methylmethacrylate. Although polymethyl methacrylate was used at the ridge lap region in all samples, the reduced bond strength in ECL teeth than other teeth could be due to the use of cross linking monomer in ECL structure, which caused higher cross linking at the ridge lap region and reduced the bond strength. The type of fracture in the teeth prepared with methylmethacrylate was the same as that of the teeth with no preparation; the only difference, however, was that the most frequent type of fracture in Ivoclar and Emeral teeth was mixed fracture. Mixed fracture is a kind of adhesive fracture with this difference that some acrylic resin remains in the cervical region possibly due to the wax investment method.
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