Microleakage of Class V resin-modified glass ionomer and compomer restorations

STATEMENT OF PROBLEM: Resin-modified glass ionomers and polyacid-modified resin composites (compomers) have been introduced to provide esthetic restorations. However, there is concern about the marginal sealing ability of these materials, especially at the dentin (cementum) aspects of restorations. PURPOSE: This in vitro study evaluated the microleakage of Class V restorations made with resin-modified glass ionomers or a compomer. MATERIAL AND METHODS: Thirty noncarious human molar teeth were used. Standardized kidney-shaped Class V cavity preparations were placed in the buccal and lingual surfaces at the cementoenamel junction. Teeth were randomly assigned to 3 experimental groups of 10 teeth each and restored as follows: group 1, Fuji II LC; group 2, Vitremer; and group 3, Dyract. In all cases, the manufacturers' instructions were strictly followed. All materials were placed in a single increment. Unfinished restorations were immediately coated with the respective manufacturers' sealer or varnish and this was either light cured for 20 seconds or allowed to air-dry. After 24 hours, teeth were finished to contour and to the cavosurface margins, coated with nail varnish except for 1 mm around the restoration margin, thermocycled (1000x, 5-55 degrees C) and placed in a solution of 2% basic fuchsin dye for 24 hours at room temperature. The staining along the tooth restoration interface was recorded. RESULTS: Kruskal-Wallis 1-way analysis of variance revealed significant differences among all restorative materials for the overall, occlusal, and gingival scores (P =.03, P =.01, P =.01, respectively). Occlusal and gingival scores for each matched pair of restorative materials using the Wilcoxon test showed statistically significant differences between Fuji II LC glass ionomer cement and Dyract composite, both for the occlusal (P =.005) and gingival (P =.005) margins and also as an overall evaluation (P =.01), with Fuji II LC showing the least dye penetration. Vitremer revealed dye penetration scores not significantly different from Fuji II LC glass ionomer cement or Dyract composite. CONCLUSION: Resin-modified glass ionomers showed less or similar microleakage than the polyacid-modified composite resin tested.     

三种牙本质粘接剂修复V类洞的微漏研究

目的 评价三种牙本质粘接剂对v类洞边缘的封闭效果。方法 30颗新拔除的正常双尖牙随机分为三组（n=10），在颊侧颈部釉牙骨质界处制备标准的v类洞（溶2mm、宽3mm）。三种粘接系统：Scotchbond Multi-Purpose，Adper PromptL-Pop，Contax和相应的修复树脂修复V类洞缺损并成形和抛光后，在37℃水中存放一周，然后进行300个冷热循环（5／55℃），最后将牙齿浸泡在296的甲基兰溶液中（37℃）24小时，将所有牙齿沿颊舌向切成两半，立体显微镜观察边缘微漏的染色情况，记录评分结果。数据进行Kruskal-WallisTest检验。结果 三种粘结剂在v类洞的釉质均没有微漏发生，AdperPromptL-Pop牙本质边缘的微涌评分结果较ScotchbondMulti—Purpose差，差异有显著性（P〈0．05），其它两组间无显著性差异。釉质边缘的整体评分明显优于牙本质边缘。结论 三种粘接系统对釉质边缘的封闭效果相对更稳定；釉牙骨质界下方的特殊预备体边缘结构可能造成边缘封闭效果不良。     

Microleakage effect on class V composite restorations with two adhesive systems using different bleaching methods

Abstract

Objective. The main objective of this study was to evaluate the effects of an at-home and two in-office (chemically activated and KTP laser-activated) bleaching methods on the microleakage of composite resin restorations bonded with etch-and-rinse and self-etch adhesive systems. Materials and methods. Class V cavity preparations were performed on 96 premolars and teeth were divided into two groups according to the two adhesive systems (etch-and-rinse and self-etch). After cavities were restored with an adhesive systems and composite resin, they were submitted to thermocycling procedures. Teeth were divided into four sub-groups according to the bleaching systems (control, at-home bleaching, chemically activated office bleaching and KTP laser-activated office bleaching). After the bleaching procedure, teeth were evaluated for marginal leakage. All data were analyzed using the Mann-Whitney U and Kruskal-Wallis tests (p < 0.05). Results. The results of the present study showed that the control group presented lower microleakage values compared with the groups treated with bleaching agents, except for the chemically activated in-office bleaching. When the scores of microleakage at the enamel and gingival margins of the four groups were compared, the differences among the groups were found to be statistically significant (p < 0.05). Comparing the gingival and enamel margins in each group, statistically significant differences were found in the at-home group (p < 0.05) and no significant differences were seen in the other groups (p > 0.05). No significant difference was found between the adhesive systems after treatment with the same bleaching techniques. Conclusion. Under the conditions of this study, microleakage of composite resin restorations differs according to the bleaching methods used and no difference was found between the adhesive systems.     

不同黏接系统应用于乳牙复合体修复的研究

目的探讨不同黏接系统应用于乳牙复合体修复后,对边缘密闭性、操作时间、操作复杂程度的影响。方法乳磨牙牙冠制备成薄片．表面制备Ⅰ类洞。分别应用黏接系统SingleBond、XenoⅢ、iBond,模拟临床操作,记录时间。温度循环法模拟体内状况处理样本后,扫描电镜观察。并行染料渗透实验。单盲法对二维微渗漏情况进行观察。结果黏接系统iBond的边缘密闭性方面明显差于XenoⅢ与SingleBond黏接系统（P〈0．05）。XenoⅢ黏接系统操作时间明显少于SingleBond与iBond黏接系统（P〈0．05）。结论自酸蚀黏接系统XenoⅢ能取得与全酸蚀黏接系统SingleBond相同的密闭性．同时缩短操作时间、减少操作的刺激性,白酸蚀黏接系统iBond边缘密闭性差,操作复杂、时间长。     

The effect of an additional flowable compomer layer on microleakage of Class V compomer restorations.

BACKGROUND: Polymerisation shrinkage and the associated stress on composite resins and surrounding structures have been regarded as a major cause of leakage and clinical failures in modern polymer restorations. The purpose of this study was to investigate the effect of an additional flowable compomer layer on the microleakage of Class V dental cavities, which were further filled with a compomer. METHOD: Cavities (32) were prepared in human premolars, conditioned with a non-rinsing agent (Prime & Bond NRC) and treated with the bonding agent (Prime & Bond NT). Sixteen of these cavities were then lined with a layer of flowable compomer (Dyract Flow, approximately 0.5 mm) and further filled with Dyract AP. The other 16 cavities were filled without the flowable compomer. The specimens were thermo-cycled in a 0.5% basic fuchsin solution, sectioned and evaluated for dye penetration using a scoring system of 0 to 4. RESULTS: Lower microleakage values were found at the enamel as well as at the dentine sides when a layer of Dyract Flow was used as a liner. Furthermore, significantly (p < 0.05) lower microleakage was found in enamel than in dentine for both layered and unlayered restorations. CONCLUSION: It can be concluded that a layer of flowable compomer (i.e. Dyract Flow) in a cavity under a compomer may be recommended to improve the marginal seal of a restoration.     

Microleakage and marginal hybrid layer formation of compomer restorations

The tested hypotheses of this study were that dentin enamel bonding agents (DBAs) proposed for compomers create a hybrid layer (HL) that seals the margins of Class V restorations and HL is free from voids or gaps on both enamel and dentin margins. For purposes of this study, Class V restorations (n = 70) were made in vitro at the CEJ in extracted third molars. Different systems (bonding agent + compomer) were selected. After finishing with discs, each margin was polished with diamond polishing paste for one minute, treated with a 2.5% NaOCl gel for 10 seconds and washed with deionized water to remove polishing debris and non-infiltrated collagen. All restorations were immersed in dye solution for 24 hours, then inspected along the margins. SEM analysis was used to evaluate the morphology of the marginal HL and microleakage tests to evaluate their ability to seal the margins of restorations. Marginal leakage was observed along the dentin and enamel margin. A thin marginal HL (0.5-1.2 microm) was detected only along the dentin margin of several bonding systems but not along the enamel margin. Porosities and gaps were detected along margins when no HL was observed. The results demonstrated that the tested bonding agents for compomers produced a thin marginal hybrid layer, especially along the dentin margin. Microleakage had a relationship with the morphology (gap, porosities and thickness) of this hybrid smear layer. In conclusion, the DBAs tested specifically developed for compomers did not ensure an intimate interfacial adaptation, because microleakage was detected along the enamel and dentin interfaces and the marginal hybrid layer was only partially homogeneous.     

Microleakage of glass ionomer/composite laminate Class V restorations

The aim of this investigation was to evaluate the effects on microleakage of pretreating dentin with polyacrylic acid (PAA), prior to placing a glass ionomer base/composite laminate restoration. Class V erosion-type lesions with the incisal margin on enamel and the cervical margin below the cemento-enamel junction (CEJ), were prepared in 50 sound extracted teeth. These teeth were divided into five dentin treatment groups: A) 10% PAA; B) 20% PAA; C) and D) 40% PAA; E) no dentin preconditioning. In groups A, B, C and E, a glass ionomer base was placed within 1 mm of the margins. In group D the glass ionomer base extended to the cervical margin. The glass ionomer base and the incisal enamel were etched with 37% phosphoric acid prior to placing a bonding agent and restoring with a composite. The restorations were finished and polished and the teeth were stored in distilled water at 37 degrees C for 7 days. They were thermocycled in 0.5% fuchsin dye for 500 cycles (5 degrees C to 60 degrees C), embedded in epoxy resin, and sectioned at 250 mu intervals through the restorations. The section of each tooth exhibiting the most severe dye penetration along the tooth/restoration interface was evaluated and scored both incisally and cervically: 0 = no leakage; 1 = leakage up to the glass ionomer base; 2 = leakage up to 1/2 the wall length; 3 = leakage exceeding 1/2 the wall length. Cervically, the median leakage for all groups was 3.0. Incisally, the median leakage for all the groups was 0.0.(ABSTRACT TRUNCATED AT 250 WORDS)     

Microleakage of Class V resin composite restorations placed with self-etching adhesives

STATEMENT OF PROBLEM: Although they are widely available, there is insufficient information about the capability of self-etching adhesives in sealing the margins of resin composite restorations. PURPOSE: The purpose of this study was to compare the in vitro microleakage of Class V resin composite restorations placed using a strong pH self-etching adhesive, an intermediate pH self-etching adhesive, and an adhesive with a separate etchant and primer. MATERIAL AND METHODS: Class V resin composite restorations (n = 8) were placed in prepared cavities in extracted human third molars using 2 self-etching dentin adhesives, Prompt L-Pop (Strong pH) or One-Up Bond F (Intermediate pH), and an adhesive with a separate etchant and primer, ScotchBond Multi-Purpose. The restored teeth received 1000 thermal cycles between 5 degrees C and 55 degrees C water baths with a 1-minute dwell time and were subsequently subjected to a methylene blue dye challenge and sectioned. The sectioned specimens were scored as demonstrating none, slight, or severe leakage (n=16). Ranked data were analyzed using a 1-way analysis of variance at a 5% confidence level. RESULTS: The only leakage observed was along gingival margins, with an incidence of 31% for Prompt L-Pop and One-Up Bond F, and 50% for ScotchBond Multi-Purpose. CONCLUSION: No significant differences in marginal leakage were found among the adhesives tested.     

The influence of three Erbium:YAG laser energies on the in vitro microleakage of Class V compomer resin restorations

Summary. Objectives . To investigate the influence of three Erbium:YAG pulse energies (200 mJ, 240 mJ, and 300 mJ with a 100 mJ dentine finish) on the microleakage of Class V compomer restorations (Compoglass).
Design . In vitro study
Sample and methods . Sixty-one extracted human premolar teeth were randomly allocated to three groups (according to pulse energy). Each tooth hosted one test cavity prepared with one of the three Er:YAG pulse energies using a pulse repetition rate of 5 Hz and a pulse duration of 250 μs, and one control cavity prepared with a conventional diamond bur in a high-speed hand piece. Both cavities were placed at the cervical margin of the tooth and were restored and finished according to the manufacturer's instructions. Each tooth was then stored in 0·12% thymol solution at 37 °C for three months, before being thermocycled through water baths between 5 °C and 55 °C for 240 cycles. Microleakage was assessed using a methylene blue dye penetration technique and was quantified using a score 0 (none) to 4 (to and into the axial wall). The data was analysed using the Kruskal–Wallis and Mann–Whitney U -tests.
Results . Leakage was seen in all groups at both the dentine and enamel margins. There were no statistically significant differences in leakage ( P < 0·05) at either the enamel or dentine margins, except for the 240 mJ lased enamel margins. This group performed significantly better than the enamel margins prepared with 200 mJ ( P  = 0·03) and the 300/100 mJ ( P  = 0·01) laser energies as well as the conventionally prepared enamel margins ( P < 0·001).
Conclusion . Cavity preparation with this Erbium:YAG laser did not influence the microleakage of Compoglass restorations adversely. Different pulse energies were required for optimum cavity sealing at the enamel and dentine margins and for different materials.     

Microleakage at gingival margins of Class V composite resin restorations rebonded with various low-viscosity resin systems

The failure of a composite resin restoration to seal at its interface with unetched tooth structures, resulting from polymerization shrinkage, creates an unwanted marginal microleakage. Rebonding with a low-viscosity resin system has been recommended to reseal the marginal gap and to reduce microleakage. Since no particular resin system is commercially available, any low-viscosity resin has been utilized for this purpose. However, findings of this study seem to indicate the importance of selecting the appropriate resin system to optimize the outcome of this rebonding procedure, emphasizing the lowest viscosity and good wettability of the system. With proper selection of the resin system, this rebonding procedure can significantly reduce the microleakage at gingival unetched margins of Class V composite restorations.     

Marginal adaptation of Class V restorations using different restorative techniques

This in vitro study compares the marginal adaptation of Class V restorations with margins located half in enamel and half in dentine, which were placed using different restorative techniques. Five operative procedures were evaluated both in saucer-shaped erosion lesions and in box-shaped cavities with bevels in enamel. The five procedures included a composite inlay technique using both the chemically and the light curing versions of a resin based composite cement, a bulk placement technique using a chemically curing composite resin, an incremental technique and an incremental technique combined with a built-up base, using a light curing composite resin. A combination of Gluma/Clearfil served as the dentinal adhesive. The micromorphology of the tooth/restoration interface was analysed before and after thermal cycling; the marginal seal was analysed after thermal cycling only. In the conventional cavities, the restorations showed less leakage, and micromorphologically a better, but statistically insignificant superior marginal adaptation. The inlay technique rendered the best marginal quality in both enamel and dentine before and after thermal cycling. Due to the unique curing characteristics of the chemically cured composite resin and cement resulting in a significantly reduced rigid contraction, the inlays cemented with the chemically curing cement and the restorations placed with the chemically curing composite resin were superior to their light cured counterparts. The built-up base yielding a reduction of the composite mass did not enhance marginal adaptation because of the partial replacement of the strong adhesion to dentine mediated by the Gluma/Clearfil combination by the weaker bond promoted by the etched glass ionomer cement.     

Microleakage of compomer class V restorations: effect of load cycling, thermal cycling, and cavity shape differences

STATEMENT OF PROBLEM. Microleakage is an important problem with direct filling restorations and an understanding of the factors that contribute to it is of critical importance. PURPOSE. This study investigated the effect of thermal and occlusal load cycling, and limited cavity preparation on microleakage of compomer Class V restorations in vitro. MATERIAL AND METHODS. Class V cavities were randomly prepared on the buccal and lingual surfaces of 32 recently extracted molars and premolars and restored with Dyract compomer restorative system as per the manufacturer's directions. Teeth were randomly assigned to 1 of 4 treatment groups with 8 teeth in each group: (I) thermocycling only; (II) load cycling only; (III) both thermocycling and load cycling; and (IV) no treatment. All teeth were then immersed in 2% basic fuchsin solution for 24 hours. Dye penetration was measured linearly using color photographic prints. ANOVA, comparisons between means, and correlation were used to analyze the results. RESULTS. Thermocycling and cavity preparation had a significant effect on microleakage, but load cycling did not. Occlusal margins leaked more than the gingival margins. CONCLUSION. Class V restorations demonstrated increased microleakage under the conditions of thermal cycling and nonretentive cavity design. More microleakage occurred at occlusal margins than at gingival margins. The effect of load cycling is complicated by considerations of the types of stresses applied and the restorative material response to such stresses.     

Microleakage in bonded amalgam restorations using different adhesive materials

The aim of this study was to verify the ability of different adhesive materials to prevent microleakage in bonded amalgam restorations. Standard cavities were prepared in both buccal and lingual surfaces of 35 bovine incisors. The gingival wall was located in cementum/dentin and the occlusal wall in enamel. Teeth (n=35) were divided into 5 groups, according to material employed (one glass-ionomer cement, two resin cements, one adhesive system, and Copalex varnish as a control). Following restoration, the teeth were submitted to thermal cycling. The teeth were subsequently immersed in methylene blue dye and sectioned to allow assessment of microleakage. Non-parametric statistical analysis indicated that all materials demonstrated less leakage than the control group (p<0.01). No leakage was found using the resin-modified glass-ionomer cement, which was significantly different from the other adhesive materials (p<0.05). Leakage in enamel was lower than in cementum/dentin margins. It was concluded that bonded amalgam was an effective technique, since all materials prevented microleakage in enamel and cementum/dentin, when compared to the control group, except Panavia in cementum/dentin margins.     

Microleakage in class V composite and compomer restorations following exposure to a colutory prescribed for the treatment of xerostomy

The purpose of this study was to evaluate the effect of a colutory (XeroLacer, Lacer), prescribed for the treatment of xerostomy, on microleakage into class V cavities filled with a composite (Z100, 3M ESPE) or a compomer (F2000, 3M ESPE) in combination with either a two-step etch-and-rinse adhesive (Adper Scotchbond 1XT, 3M ESPE) or a self-etching adhesive (Adper Prompt L-Pop, 3M ESPE). Class V cavities were made in the buccal surfaces of 80 bovine lower incisors which were randomly divided into four groups (n = 20): (1) Adper Scotchbond 1XT/Z100; (2) Adper Scotchbond 1XT/F2000; (3) Adper Prompt L-Pop/Z100; and (4) Adper PLP/F2000. All specimens were immersed in distilled water for 3 months and ten specimens of each group were immersed and vibrated in XeroLacer for 2 min three times a day. The specimens were dyed with 1% methylene blue for 24 h. Longitudinal sections were made and percentages of microleakage were determined by image analysis. In distilled water, microleakage with the Adper Scotchbond 1XT/F2000 combination was significantly greater than with Adper Scotchbond 1XT/Z100 or Adper Prompt L-Pop/Z100, and microleakage with Adper Prompt L-Pop/F2000 was significantly greater than that with Adper Prompt L-Pop/Z100. No significant differences were detected among the groups exposed to XeroLacer. However microleakage was significantly less with Adper Scotchbond 1XT/F2000 after exposure to XeroLacer than after immersion in distilled water only. In conclusion, exposure to XeroLacer decreased microleakage into cavities restored with the compomer.