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1.
Amalgambond Plus with a high-performance additive was evaluated for its ability to bond a resin composite or an amalgam alloy to deep dentin in primary teeth with nonretentive cavity preparations. The clinical performance of amalgam and resin composite mesio-occlusodistal restorations bonded with Amalgambond Plus was evaluated at 15 months and 2 and 3 years. There was no statistically significant difference in the retention, marginal adaptation, secondary caries, and post-operative sensitivity over the times of the evaluation or between amalgam and resin composite restorations. After 3 years, most of the teeth were extracted because it was their exfoliation time, and 29 restorations limited within buccal and lingual cusps were evaluated for marginal leakage. There were no significant differences in microleakage between amalgam and resin composite restorations lined with Amalgambond Plus. Amalgambond Plus has the potential for serving successfully as a cavity liner with either amalgam or resin composite restorations.  相似文献   

2.
An in vitro dye leakage study was performed to compare the sealing ability of glass ionomer, composite resin and glass ionomer/resin cement when used as restorative materials for G.V. Black class V cavities. In this research, standard Class V cavities were prepared in sound premolar teeth extracted for orthodontic reasons. The cavities were randomly divided into 3 groups. After filling the cavities with glass ionomer cement, composite resin and light curing glass ionomer/resin cement, the specimens were immersed in silver nitrate solution. Marginal microleakage at the interface between the cavity wall and restoration was evaluated. The results were analyzed by using Kruskal-Wallis and Mann Whitney U tests. Result of this in vitro study indicate that composite resin and glass ionomer/resin cement provide a better seal than glass ionomer cement.  相似文献   

3.
The aim of this study was to compare the clinical performance of an amalgam, a glass polyalkenoate (ionomer) cerment material and a resin-based composite material used in small Class II cavities in permanent teeth. All restorations were inserted under rubber dam. They were examined yearly for 3 years. One clinician continued the study up to 5 years. The clinical examination focused on two criteria: clinically acceptable and failure. In addition, impressions were taken of the prepared cavities immediately before restoration and at each clinical examination using an elastomeric material. The study comprised 274 Class II restorations (88 amalgams, 95 cerments and 91 resin composites) placed in 142 adolescent patients. One hundred and sixty-seven restorations were in molar and 107 in premolar teeth. Patient dropout after 5 years resulted in the loss of 161 restorations, evenly distributed for restorative material and type of tooth involved. Four amalgam restorations, 22 glass ionomer cerment and nine resin composite restorations failed. The glass ionomer cerment and amalgam restorations failed primarily due to bulk fractures, while the resin composite restorations failed due to secondary caries and bulk fractures.  相似文献   

4.
OBJECTIVE: Marginal leakage of amalgam restorations may lead to secondary caries and pulpal damage. The purpose of this study was to determine the effect various cavity liners might have on microleakage. METHOD AND MATERIALS: Mesio-occlusodistal amalgam restorations with margins on enamel and dentin were treated with different liner materials (an adhesive system, a topical fluoride gel, a cavity varnish, and a glass-ionomer cement) in vitro. Following restoration, the teeth were submitted to thermocycling in a stained solution and sectioned to allow assessment of microleakage. RESULTS: On enamel, the control group (no liner) and the glass-ionomer-lined group had equivalent leakage scores and were superior to every other group. On dentin, only the glass-ionomer specimens had superior performance. The cavity varnish and fluoride-lined specimens exhibited the highest leakage scores. CONCLUSION: The use of liners does not reduce microleakage on amalgam restorations when the cavity margins remain on enamel. On dentin margins, a glass-ionomer liner can reduce microleakage.  相似文献   

5.
PURPOSE: To compare the in vitro strength of a reinforced glass ionomer and a light-cured glass ionomer used as an alternative to amalgam in core construction to restore endodontically treated mandibular molar teeth. MATERIALS AND METHODS: The root canals of 120 extracted human mandibular molar teeth were prepared chemomechanically and obturated with laterally condensed cold gutta-percha. The crown of each tooth was sectioned leaving only one cusp standing. Gutta-percha was removed from the pulp chamber in all teeth. The volume of the pulp chamber was measured and the teeth ranked in ascending order of chamber volume. The specimens were divided into six groups of 20, allocating teeth with similar chamber volumes into each group. In three of the groups, gutta-percha was removed from the coronal 3-4 mm of each root canal. The teeth were restored with one of three materials, a cermet cement (Ketac-Silver), a resin-reinforced glass ionomer (Vitremer), or amalgam (Contour). Core preparation was carried out after 48 hours, reducing each core height to 6 mm. The specimens were thermocycled for 24 hours and then mounted in dental stone. A control group of 20 unrestored human mandibular molars was mounted in cold cure acrylic. Each tooth was tested in a Nene machine with a compressive load applied at 90 degrees to the occlusal surface at a crosshead speed of 5 mm/minute. RESULTS: There was no statistically significant difference between the experimental groups (P > 0.05), but the control group was significantly stronger (P < 0.001). Extension of core material into the coronal root canal system did not increase the fracture resistance of any of the experimental materials. Regression analysis of the results revealed no correlation between the volume of the pulp chamber and the load to fracture.  相似文献   

6.
The short-term tissue responses to two potential root-end filling materials, a light-cured glass ionomer cement (Vitrebond) and a reinforced zinc oxide-eugenol cement (Kalzinol), were compared with that to amalgam using a previously devised experimental model. In 24 premolar teeth of beagle dogs (47 roots), a collection of endodontic pathogenic bacteria was first inoculated into the root canals to induce periradicular lesions. On each root, an apicoectomy was performed and root-end cavities prepared to receive fillings of each material. The teeth and surrounding jaw were removed after 2 weeks (23 roots) and 1 week (24 roots); they were then prepared for histological examination. The tissue response to amalgam fillings after 2 weeks and 1 week was marked by moderate or severe inflammation on all roots, and extended to < or = 0.5 mm or > 0.5 mm in 15 out of 16 roots. In contrast, after 2 weeks, the majority of roots filled with Kalzinol showed little or moderate inflammation, while the tissue response to Vitrebond was the best of the three materials, and was also the least extensive. After 1 week, the overall best tissue response was with Vitrebond, followed by Kalzinol. The differences between materials for both time periods with either none or few inflammatory cells when compared with that with either moderate or severe inflammation were not statistically significant (P < 0.02). However, the differences between materials for both time periods with no inflammation or inflammation extending < 0.2 mm when compared with that with inflammation extending > 0.2 mm (< or = 0.5 mm or > 0.5 mm) were statistically significant (P < 0.01). Apart from amalgam, in which healing was marked by the persistence of a localized focus of inflammation adjacent to the root-end filling, even though there were intersample variations, there was little overall difference in the temporal and qualitative healing response to Vitrebond and Kalzinol. Both Vitrebond and Kalzinol have potential as root-end filling materials, as the tissue response was considerably more favourable than that to amalgam even in the short-term.  相似文献   

7.
OBJECTIVES: Recurrent caries is one of the most common reasons for the replacement of restorations. One method of reducing the frequency of this problem may be by using fluoride-releasing restorative materials. The aim of this in vitro study was to evaluate the progression of artificial lesions around resin-modified glass ionomer (Vitremer) restorations placed in root surfaces. Class V cavities were prepared on the mesial and distal surfaces of 28 human premolar teeth. Artificial carious wall lesions were created in all cavities. The root of each tooth was then hemisected through the middle of the two cavities, before being restored with either the glass ionomer or amalgam, while the opposing cavities on the same root portion were varnished as negative controls. Forty-eight specimens were pH-cycled in remineralising and demineralising solutions for 20 h and 4 h, respectively, each day for 4 weeks, whilst in a smaller control group of eight specimens, the demineralising solution was replaced with deionised water. Mineral changes in the carious lesions were evaluated using contact microradiography. RESULTS: Results showed that varying degrees of subsurface demineralisation and remineralisation were evident, with a laminated appearance in lesions adjacent to the glass ionomer. There was higher remineralisation in the glass ionomer-filled cavities compared with the amalgam-filled cavities. In the water-cycled group, glass ionomer showed an increase in mineral content (p < 0.05), while no changes were observed in the amalgam-filled cavities. CONCLUSIONS: This model has shown that glass ionomer has a greater potential than amalgam for remineralisation of artificially created wall lesions within an acidic environment.  相似文献   

8.
Various sealing techniques using a light-curing dental adhesive (Scotchbond 2) and bulk application of a light-curing resin-bonded ceramic were examined in 203 Class II cavities. Different pretreatment procedures and lining materials were used, and in one series resin impregnation of the contraction gap was included. The presence of gaps or leakage was disclosed either by a dye or a fluorescent resin penetration technique. In many restorations, Scotchbond 2 and a light-curing glass-ionomer lining did not prevent gap formation at the cervical wall. The gap usually occurred between the liner and the dentin, with dye penetration into the dentin. Three liners, one containing polytrifluorethylene sodium fluoride and calcium fluoride, one containing polyamide resin, and one containing calcium hydroxide, did not prevent dye penetration to the dentin at all; good dentinal protection was frequently observed, however, in cavities treated with a hydrophilic shellac film prior to placement of a polystyrene liner. The best results were observed when dentinal treatment with this lining system was followed by resin impregnation of the contraction gap after the composite resin had set.  相似文献   

9.
PURPOSE: To compare the shear bond strengths to dentin of four tooth-colored fluoride-releasing restorative materials that utilize different mechanisms of dentin-bonding. MATERIALS AND METHODS: Four materials were tested: a chemically-cured glass ionomer (Ketac-Fil); a light-cured resin-modified glass ionomer (Photac-Fil); a light-cured resin-modified glass ionomer in conjunction with a resin dentin-bonding agent (Vitremer); and a light-cured resin composite in conjunction with a resin dentin-bonding agent (Tetric). The enamel was removed from four sides of the twenty human noncarious extracted molars which had their roots embedded in acrylic blocks. Cylindrical samples of the materials were prepared in plastic molds and bonded to the dentin surface according to the manufacturers' instructions. After 24 hours of storage in a humidor, the samples were sheared with an Instron testing machine at a crosshead speed of 0.5 mm/minute. RESULTS: Statistical evaluation (ANOVA and Duncan's test) suggests that the fluoride-releasing resin composite material utilizing a resin dentin-bonding agent provided a significantly greater mean shear bond strength (16.5 MPa) after 24 hours storage than any of the selected glass ionomer materials. Of the three glass ionomer materials compared, the light-cured resin-modified material with a resin dentin-bonding agent provided a significantly greater mean shear bond strength (6.7 MPa) than the light-cured resin-modified material without a resin dentin-bonding agent (3.0 MPa) or the chemically-cured material (3.8 MPa).  相似文献   

10.
The objective of this study was to determine the in vitro shear bond strength (in megapascals) and location of bond failure with two light-cured glass ionomer resin systems. One system was a hybrid glass ionomer cement with resin (GC Orthodontics, Aslip, Ill), and the other system a glass-filled resin system (Reliance Orthodontic Products, Inc, Itasca, Ill). These systems, Fuji Ortho LC (GC Orthodontics) and Ultra Band Lok (Reliance), respectively, were compared to a light-cured composite resin. Maxillary premolar brackets (n = 200) were bonded to the facial surface of human premolar teeth. The two glass ionomer resin systems were each evaluated by two protocols, one according to the manufacturers' direction plus a variation of their respective technique. The five distinct groups (n = 40) were stored in 37 degreesC distilled water for 30 days and subjected to thermocycling before shear bond strength testing. The findings indicated that large variations existed between the bond strengths of the materials tested. The laboratory shear bond strength of the glass-filled resin glass ionomer cement (Reliance), whether tested in a dry or moist field, was similar to the composite control with all of the previous materials being significantly (P <.01) higher than both the hybrid glass ionomer cement groups (Fuji Ortho LC). However, the hybrid glass ionomer cement with enamel conditioner demonstrated a clinically acceptable mean megapascal value. The Adhesive Remnant Index values ranged from 0.53 to 1.62. The hybrid glass ionomer cement without enamel conditioning recorded the lowest mean adhesive remnant index score and the lowest mean megapascal score. Although both products are glass ionomer resin systems, their individual chemistries vary; this affects their clinical performance. Clinically, it may be suggested that glass ionomers used in a dry field may be beneficial for orthodontic bonding, and that glass ionomer resin systems used in a moist environment need an enamel conditioner.  相似文献   

11.
This study evaluated the preparation of root-end cavities using an ultrasonically activated file, and the obturation of such cavities. In the first part, the root canals of 40 extracted teeth were prepared to size 40 and irrigated with NaOCl and EDTA. The root ends were resected and the teeth inoculated with Enterococcus faecalis, incubated for 10 days and divided into four groups: control; saline; irrigation; hand instrumentation performed via a retrograde approach up to size 50 using saline irrigant; ultrasonic instrumentation with prebent size 40 K-flex file inserted into a Piezon Master using saline irrigant. The teeth were fixed, sectioned longitudinally and viewed under scanning electron microscopy. Bacterial and smear layer scores were obtained at 1, 3, and 5 mm from the resected end. The bacterial scores for control and saline groups were similar; the scores for each instrumentation group were significantly lower than the control group (P<0.001). In addition, there were significantly fewer bacteria in the ultrasonic group compared with the hand instrument group (P<0.001). The smear layer scores for control and saline groups were similar, and significantly lower than in either instrumentation group (P<0.001). In the second part, root-end cavities were ultrasonically prepared in 20 extracted teeth. Ten cavities were filled with amalgam, and 10 with thermoplasticized gutta-percha and Grossman's sealer. After 24-h storage, the root ends were immersed in dye for 48 h. Cross-sectional slices of the obturated part of the root were evaluated using both light and confocal microscopy for dye leakage along the interface of filling material and dentine. There were no statistical differences between the leakage of amalgam and gutta-percha root-end fillings, nor between the two methods of microscopy.  相似文献   

12.
Microleakage of conventional chemically cured and resin modified glass ionomer cements (GIC), a compomer and a composite resin was studied in vitro in direct class V and class II GIC/composite sandwich fillings. None of the restorative techniques investigated completely resisted microleakage at both the occlusal and gingival margins. The dentinal gingival margins exhibited the highest leakage pattern. The compomer and the resin modified GIC showed a better seal than the chemically cured GIC's. The use of a liner as separating agent between composite resin and GIC in the class II sandwich fillings did not improve the seal. The results suggest that the initial bond obtained immediately after light curing of the resin modified GIC's is stronger than that for chemically cured GIC's. The contradictory results of dye leakage studies reported in the literature are discussed and in vivo evaluations are suggested necessary to predict clinical performance.  相似文献   

13.
OBJECTIVES: The effect of non-carious cervical lesions (NCCL) on tooth fracture resistance has not previously been investigated. The aims of this in vitro study were to examine the fracture resistance of a group of extracted maxillary premolar teeth with mesio-occlusal-distal (MOD) restorations of amalgam, and restored or unrestored simulated NCCL. METHOD: Forty sound maxillary, premolar teeth were divided at random into four groups, each of 10 teeth, which were fixed crown uppermost and long axis vertical in stainless steel moulds. Groups 1,2,3 and 4 were prepared with standardized parallel-sided MOD cavities, then restored with amalgam. Groups 1, 2 and 3 were further prepared with standardized NCCL. The NCCL in Group 1 were restored using a resin-modified polyalkenoate (glass-ionomer) cement, and the NCCL in Group 2 were restored with an adhesive composite resin system. The NCCL in Group 3 were left unrestored. The specimens were loaded compressively at 1 mm min-1 using a universal testing machine. RESULTS: Mean fracture loads (KN) of 1.08, 1.03, 0.98 and 1.14, respectively, were recorded for Groups 1, 2, 3 and 4. Two-way ANOVA and Scheffe's Multiple Range Test showed no statistically significant difference between the groups. CONCLUSIONS: It is concluded that the presence of a standardized NCCL in an extracted maxillary premolar tooth does not reduce the fracture resistance of the tooth when loaded compressively at 1 mm min-1. The restoration of NCCL with the materials tested did not result in an increase in the fracture resistance of the previously restored premolar teeth, when loaded compressively at 1 mm min-1.  相似文献   

14.
PURPOSE: To evaluate the effectiveness of the dentin bonding systems (DBS) Tenure, Syntac, Amalgambond and All-Bond 2 using a resin-lined amalgam technique in preventing short-term microleakage in Class V cavity preparations restored with a spherical and an admixed alloy. MATERIALS AND METHODS: Class V cavity preparations were made on the mesial and distal surfaces of non-carious human mandibular molars with the occlusal margins in enamel and gingival margins in cementum. Prepared teeth were randomly assigned to 12 treatment groups (n = 10) consisting of each DBS, no liner and Copalite for both amalgam alloys. Samples were thermocycled, stained and sectioned to evaluate microleakage. RESULTS: The DBS-lined restorations had significantly less microleakage at both occlusal and gingival margins than the Copalite and unlined restorations. Among DBS, Syntac had significantly more microleakage with both alloys than either All-Bond 2 or Amalgambond. These results do not totally correlate to a previous study which used the same experimental design but included viscous liners in addition to the same DBS, indicating a potential difference between resin-lined versus resin-bonded amalgam techniques in preventing microleakage.  相似文献   

15.
In an in vitro study, the use of sealers and liners (Fuji varnish, Vitrabond, Vitremer, Paama 2, All-Bond 2, or Resinomer) significantly reduced the amount of marginal leakage around amalgam (Permite C or Lojic Plus) and gallium (Galloy) alloy restorations. This reduction in marginal leakage was produced by all sealers and liners tested, and there were no statistically significant differences between these materials. Unlined restorations of Permite C had significantly less marginal leakage than Galloy or Lojic Plus. Unlined Lojic Plus restorations had the greatest amount of marginal leakage. The experimental method used in the present study proved to be suitable for quantitative comparison of marginal leakage of different dental materials.  相似文献   

16.
PURPOSE: To evaluate the shear bond strength to the dentin of permanent teeth and failure site of Dentastic hydrophilic dentin bonding agent. MATERIALS AND METHODS: Forty permanent noncarious molar teeth stored in distilled water were obtained. The teeth were cleaned with pumice and a rubber cup. The mesio-buccal surface of the teeth was ground flat with hand pressure with a series of SiC paper ending with the 600 grit to provide a uniform surface on dentin to which the resin composite could be applied. After preparing the tooth surface, the teeth were stored in distilled water for 48 hours. They were then divided at random into four groups of 10 specimens each: Group 1: Dentastic, five coats of primer; Group 2: Dentastic, three coats of primer; Group 3: Dentastic, five coats of primer, light-cured adhesive before resin bonding; Group 4: Dentastic, three coats of primer, light-cured adhesive before resin bonding. All specimens were thermocycled (500x) and sheared in a testing machine. After shear testing, the debonded sites of all samples were examined with a stereomicroscope and a scanning electron microscope. RESULTS: The results in MPa were: Group 1: 22.63 +/- 6.24; Group 2: 23.35 +/- 5.14; Group 3: 23.58 +/- 5.66; Group 4: 27.26 +/- 8.22. ANOVA and Student-Newman-Keuls showed no statistically significant difference between the groups. In all groups, all specimens failed at the dentin (dentin cohesive failure = dentin fracture) or at the resin (resin cohesive failure = resin fracture). This means that the bond strength of the product is stronger than the cohesive strengths of the dentin and the resin.  相似文献   

17.
INTRODUCTION: Problems that may arise in resin composite Class 2 restorations include microleakage and postoperative sensitivity. However, limited in-vivo research is conducted to evaluate these processes. AIM: The aim of this study was to assess postoperative sensitivity, microleakage and the pooling of adhesives in relation to Class 2 box-type composite restorations placed in vivo using various adhesive systems and application techniques. MATERIALS AND METHODS: One hundred and forty-four Class 2 box restorations were placed in the mesial and distal surfaces of 72 premolar teeth in-vivo using one of three combinations of adhesive systems and three filling techniques. After 6 weeks of clinical service postoperative sensitivity was recorded. The teeth were then extracted, immersed in a dye solution and sectioned. Microleakage and pooling of the adhesive was recorded. Statistical analysis involved logistic regression and chi2 tests to identify differences between groups at p < 0.05. RESULTS: Of the 144 restorations, 65 showed minimal cervical leakage in enamel, 5 suffered leakage into dentin and 74 were free of microleakage. No statistically significant differences were found in cervical microleakage between the adhesive systems or between filling procedures. Occlusal microleakage in the enamel was present in 16 of the 160 restorations. Liner Bond 2 restorations leaked significantly more at the occlusal surface (p < 0.05). Pooling of the adhesive was significantly less when PhotoBond was used. No spontaneous postoperative sensitivity was reported. Twenty-eight restorations were sensitive to loading. Postoperative sensitivity was significantly less in patients with Liner Bond 2 restorations. CONCLUSIONS: The adhesive systems used in this study showed minimal leakage into dentin in vivo. Using Liner Bond 2, restorations exhibited more occlusal leakage but were significantly less sensitive to loading.  相似文献   

18.
Secondary caries is one of the most important factors leading to replacement of dental restorations. This investigation assessed the capacity of fluoride-releasing restorative materials to resist caries in vitro when used in roots. Class 5 cavities were prepared in the buccal and lingual surfaces of 30 extracted premolars. The six materials used were: glass-ionomer cement (Fuji), glass-ionomer cement with silver particles added (Ketac-silver), fluoride-containing composite resin (Tetric), composite resin (Silux plus), fluoride-containing amalgam (Fluor-Alloy) and high-copper amalgam (Dispersalloy). After 5 weeks in an acid gel for caries-like lesion formation, the teeth were sectioned longitudinally and examined with polarized light. The results showed that repair with glass-ionomer materials of a carious lesion may be of great importance in the prevention of secondary caries around the restorations in roots.  相似文献   

19.
The purpose of this study was to evaluate the ability of mineral trioxide aggregate (MTA) and amalgam to seal furcal perforations in extracted human molars using an anaerobic bacterial leakage model. Furcal perforations were made in 39 maxillary and mandibular human molars with a high-speed bur. These were randomly divided into two experimental groups of 18, with the remaining three teeth used as positive controls. Experimental group 1 was repaired with MTA and group 2 with amalgam. Three additional teeth without perforations served as negative controls. A dual chamber anaerobic bacterial leakage model was assembled. Brain heart infusion broth with yeast extract, hemin, menadione, and the chromogenic indicator bromcresol purple was used as the culture broth for Fusobacterium nucleatum. Eight of 18 amalgam samples leaked, whereas none of the 18 MTA samples leaked. MTA was significantly better than amalgam in preventing leakage of F. nucleatum past furcal perforation repairs.  相似文献   

20.
PURPOSES: To evaluate (1) the shear bond strength to the dentin of primary teeth and failure site of hydrophilic dentin bonding agents, (2) the interfacial micromorphology of these adhesives on primary teeth. MATERIALS AND METHODS: Seventy-six primary noncarious molars stored in distilled water were obtained. The teeth were cleaned with pumice and a rubber cup. The mesio-buccal surface of the teeth was ground flat with hand pressure with a series of SiC paper ending with the 600 grit to provide a uniform surface on superficial dentin to which the adhesives and resin composite could be applied. After preparing the dentin surface, the teeth were stored in distilled water for 48 hours. They were then rinsed and dried with compressed air and divided at random into four groups of 16 specimens each: Group 1: Dentastic; Group 2: One-Step; Group 3: Prime & Bond 2.0; Group 4: Compoglass SCA. Z100 resin was used in all groups. All specimens were thermocycled (500x) and sheared in an Instron machine. After shear testing, the debonding sites of all samples were examined with a stereomicroscope and selected samples were also examined with the scanning electron microscope. Three additional samples per group were used to evaluate the resin adaptation to dentin. RESULTS: The results in MPa were: Dentastic 19.62 (4.67); One-Step 11.24 (3.67), Prime & Bond 22.38 (6.47), Compoglass SCA 18.88 (4.04). ANOVA (P < 0.0001) revealed that there was a significant difference between the groups. The Student-Newman-Keuls test (P < 0.05) showed no statistically significant difference between Dentastic, Prime & Bond and Compoglass SCA. However, these three groups were statistically significantly higher than One Step. In the Dentastic group, 14 of 16 samples revealed resin cohesive failure (resin fracture) while two of 16 displayed dentin cohesive failure (dentin fracture). In the One Step group, 15 samples failed at the resin and one sample showed dentin cohesive failure. In the Prime & Bond group, 12 specimens revealed resin cohesive failure while four displayed dentin cohesive failure. In the Compoglass SCA group, 13 samples had resin cohesive failures while three had dentin cohesive failures. All samples revealed an intimate adaptation to the dentin displaying resin tag formation.  相似文献   

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