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PubMed2002

[Water absorption of five dental resins used in bonded restorations].

The actual restorative dentistry need to bond material which are under the constraint of saliva likely, as all liquid, to enter inside the product with time and to modify its characteristics. In this study, we compare the behaviour of five materials opposite water absorption, in vitro, until one year: two composite resins (Tetric et Pertac II), two ceromer (ceromer (Tetric ceram et Tetric flow) and one compomer (Hytac(r)). Each pastille weight is expressed in percentage of initial weight. All materials loose weight in the first hours except Tetric ceram which stay stable. At 48 h, all materials except Pertac II get back their initial weight. At long-term, all the materials are stable with a profit of 1% for Hytac, 0.5% for Tetric, Tetric ceram et Tetric flow and a loss of à 0.3% for Pertac II. As a result of this study, we understand why the clinical used of Hytac must be done following strict conditions.

Absorption↗
PubMed2002

Clinical evaluation of Dyract AP restorative in permanent molars: 2-year results.

PURPOSE: To evaluate the clinical behavior of a compomer restorative system, Dyract AP, placed in combination with Non-Rinse Conditioner and Prime&Bond NT in permanent posterior teeth. MATERIALS AND METHODS: Fifty Class II and 41 Class I restorations were placed in 39 patients in a dental teaching hospital. The restorations were evaluated directly at baseline and after 6, 12 and 24 months using the modified USPHS-Ryge criteria. Clinical photographs, polyvinylsiloxane impressions and bitewing radiographs of each restoration were taken for indirect assessment. RESULTS: After 2 years, all 76 restorations were evaluated in situ. Color matching ability and surface characteristics were excellent. A gradual deterioration in marginal discoloration and marginal integrity was noted. The percentages of Alfa scores for each criterion at the 24-month evaluation were: color match 96%, marginal discoloration 50%, marginal integrity 26%, anatomic form 97% and surface texture 95%. Five of the restorations (6%) had experienced partial fracture or recurrent caries. After 6, 12 and 24 months, the net mean occlusal wear values were 18.5 microm, 35.7 microm and 55.9 microm, respectively. There was no statistically significant difference between Class I and II restorations for each criterion (Fisher's exact test, P > 0.05).

Adult↗
PubMed2003

3-year evaluation of a new open sandwich technique in Class II cavities.

PURPOSE: To evaluate the durability of a new open sandwich restoration with, as shown in a previous scanning electron microscope study, improved interfacial adaptation. A polyacid-modified resin-based composite (PMRC; compomer) was placed as an intermediate layer and covered with resin composite (RC). A direct RC restoration was used as control. MATERIALS AND METHODS: Of 57 patients, each received at least one pair of Class II restorations, one PMRC/RC open sandwich and one RC control. In total, 75 pairs of Class II restorations, 68 premolars and 82 molars, all in occlusion, were placed by two dentists. Most of the cavities were surrounded by enamel. The restorations were evaluated at baseline, 6, 12, 24 and 36 months by a slightly modified USPHS criteria. RESULTS: Five of 148 restorations evaluated during 3 years were rated as unacceptable. Two, one in each group, because of endodontic treatment and one RC restoration was replaced because of tooth fracture. Secondary caries was observed contiguous to one restoration in each group at the 36-month recall. Except for the two patients with pulpitis, none of the others reported postoperative sensitivity. No significant differences were seen between the restoration techniques. For marginal adaptation a significant change occurred between baseline and 6 months in both groups. For marginal discoloration, a significant change was observed at 6 months in the sandwich group and at 36 months in the RC group. Color match of the resin composite material changed significantly in both groups at 36 months. It was concluded that both techniques showed good durability during the 3-year follow up.

Adolescent↗
PubMed2003

Effects of lining materials on microleakage and internal voids of Class II resin-based composite restorations.

PURPOSE: To evaluate the ability of various lining materials to reduce cervical marginal microleakage and internal voids within Class II resin-based composite restorations. MATERIALS AND METHODS: 168 extracted molars were prepared with both moderate and deep Class II cavities. The teeth were then randomly divided into 14 groups and restored with direct composite or sandwich techniques using various lining materials [flowable composites, compomers and resin-modified glass-ionomer cements (RMGI)]. Following restoration, the teeth were stored for 24 hours, thermocycled, and placed in fuchsin dye for 24 hours. Subsequently, the teeth were sectioned in halves and observed through a stereomicroscope. Cervical microleakage and internal voids were assessed separately as the length ratio of dye penetration to the cervical wall and the area ratio of voids to sectioned restorations. The data were analyzed with one-way ANOVA. RESULTS: Flowable composite lining groups demonstrated either similar or more cervical microleakage than did their respective direct restoration groups. Groups lined with RMGIs showed similar or better marginal sealing than did their resin restoration groups. In deep cavities, Vivaglass Liner group showed the best marginal sealing. RMGI-lined groups exhibited more internal voids in deep restorations.

Compomers↗
PubMedDate not supplied

Fluoride release and uptake capacities of fluoride-releasing restorative materials.

Many fluoride-releasing dental materials are being sold on the basis of their cariostatic properties. However, the amount fluoride release of these materials is still uncertain. This study investigated the fluoride release and uptake characteristics of four flowable resin composites (Heliomolar Flow, Tetric Flow, Wave, Perma Flo), one flowable compomer (Dyract flow), one conventional glass ionomer cement mixed with two different powder/liquid ratios (ChemFlex Syringeable and ChemFlex Condensable), one packable resin composite (SureFil), one ion-releasing composite (Ariston pHc) and one resin-modified glass ionomer cement (Vitremer). Seven discs (6-mm diameter and 1.5-mm height) were prepared for each material. Each disc was immersed in 3.5 ml of deionized water within a plastic vial and stored at 37 degrees C. The deionized water was changed every 24 hours and the release of fluoride was measured for 30 days. At the end of this period, the samples were recharged with 2 ml of 1.23% acidulated phosphate fluoride (APF) gel for four minutes. Then, all samples were reassessed for an additional 10 days. The fluoride release of all samples was measured with a specific fluoride electrode and an ionanalyzer. Statistical analyses were conducted using two-way repeated measure ANOVA and Duncan's multiple range tests. For all tested materials, the greatest fluoride release was observed after the first day of the study (p<0.01) but gradually diminished with time. During the test period, Tetric Flow released the lowest amount of fluoride; however, no statistically significant difference was found from Wave and Heliomolar Flow (p>0.05). Ariston pHc released the highest amount of fluoride, followed by ChemFlex Syringeable, Vitremer and ChemFlex Condensable. There were statistically significant differences among these materials (p<0.05). Fluoride release of all materials were significantly increased after the first day following refluoridation and Ariston pHc released the greatest among all materials (p<0.01). At the end of two days of refluoridation, the fluoride release rate for each material dropped quickly and stabilized within three days.

Acidulated Phosphate Fluoride↗
PubMedDate not supplied

Early detection of secondary caries using quantitative, light-induced fluorescence.

The authors hypothesize that the arrestment and remineralization of these lesions could be improved if secondary caries could be detected and monitored at earlier stages. Traditional diagnostic techniques detect secondary caries when it is relatively advanced and when significant tissue has been lost. This in vitro study evaluated the Quantitative Light-induced Fluorescence (QLF) system for detecting and monitoring demineralization surrounding tooth-colored restorations. This investigation was divided into three studies. The first study evaluated QLF for the detection and measurement of chemically induced lesions surrounding resin composite restorations. The second study evaluated QLF for the detection of demineralization around different tooth-colored restorations (glass ionomer, resin composite, compomer and smart material) created in a microbial caries model. Finally, the third study tested whether QLF was effective at detecting early wall lesions adjacent to resin composite restorations. Data from Study 1 demonstrated the potential for QLF to detect very early secondary caries and to distinguish between the different stages of early demineralization. Study 2 confirmed the potential for QLF to detect early secondary caries created by cariogenic bacteria and concluded that the four types of materials differed in their ability to prevent secondary caries in this model, with the glass ionomer being the most effective and the non-fluoride releasing composite performing the worst, which allowed for the development of larger lesions. The results of Study 3 suggest a potential application of the QLF system to detect early wall lesions. Data from this investigation strongly suggest that QLF is a potentially viable technology to detect and monitor early secondary caries.

Analysis of Variance↗
PubMed2003

Effect of biological contamination on dentine bond strength of adhesive resins.

The purpose of this in vitro study was to determine the effect of saliva (S) and blood (B) contamination on the dentine bond strength of two single-component dentine bonding systems. The occlusal thirds of 120 recently extracted, human molars were removed with a low speed saw and subsequently embedded in Bencor rings by means of self-curing, acrylic resin. The occlusal surfaces were ground wet on 600-grit silicone carbide paper in a polishing machine to expose superficial dentine and to create a smear layer. The teeth were randomly divided into 12 groups (n = 10). All the dentine surfaces were etched with 34% phosphoric acid for 15 seconds rinsed with water, air-dried for 3 seconds, leaving the surfaces visibly moist. For the control groups (C) the etched dentine surfaces were treated with either, Scotchbond 1 (SB1, 3M) or Prime & Bond NT (PBNT, Dentsply) according to the manufacturer's instructions. In the contaminated groups, the saliva or blood was applied by means of a disposable brush, left undisturbed for 1 minute, and the excess then thinned by air spray. The dentine bonding systems were then applied, also according to manufacturer's instructions. Composite (Z250 and TPH) and Compomer (F2000 and Dyract AP (D-AP)) stubs were packed and cured incrementally to the corresponding pretreated dentine surfaces. All specimens were stored for 24 hours under water at 37 degrees C. The bonds were then stressed to failure with a Zwick testing machine, operating at a crosshead speed of 0.5 mm/min. Fractured samples were examined in a Scanning Electron Microscope. The data were statistically analysed (Student-t test). The mean SBS (MPa) were. SB1 with Z250: C = 19.1 +/- 4.4; S = 17.3 +/- 3.5; B = 2.6 +/- 0.9; SB1 with F2000: C = 11.8 +/- 3.3; S = 9.7 +/- 1.8; B = 4.7 +/- 1.6. PBNT with TPH: C = 9.2 +/- 3.2; S = 6.5 +/- 3.0; B = 4.3 +/- 1.5; PBNT with D-AP: C = 10.2 +/- 3.6; S = 9.3 +/- 2.9 and B = 7.3 +/- 2.5. There was no statistical significant difference in shear bond strengths between the control and the saliva-contaminated samples for both systems. There was, however, a significant difference in bond strengths between the control and the blood-contaminated samples. Blood contamination negatively influenced bond strength of bonding systems to dentine.

Blood↗
PubMed2003

Microleakage of a single-bottle adhesive system with 3 restorative materials: in vitro study and clinical considerations.

The purpose of this study is to evaluate whether differences in material composition between 3 restoratives (compomer, packable composite, and amalgam) affect microleakage in class II preparations. Class II cavity preparations were made in the mesial and distal surfaces of a noncarious human premolar with the gingival margins in dentin. Preparations were etched and rinsed, and a single-bottle adhesive agent (Prime & Bond NT) was applied. Preparations were restored with the following materials (n = 8 per group): Dyract AP, SureFil, and Dispersalloy. For Dyract AP total-bond restorations, a new nonrinse conditioner (NRC) was tested against a total-etch with 36% phosphoric acid. Specimens were coated with nail varnish, immersed in toluidine blue for 24 hours, and evaluated for dye penetration, after removal of the restorative material, using a 0-to-4 scale. Statistical analysis using analysis of variance revealed significantly higher leakage scores (P < .05) for the NRC-Dyract AP group when compared with all other groups. Dispersalloy had significantly lower scores compared with Dyract AP and SureFil, all with the total-etch bonding technique. No statistically significant difference was observed between the latter 2 groups. The inability of all 3 materials to create a perfect seal in vitro raises concerns about the ability of the adhesive system to provide completely sealed restorations in vivo. However, bonded amalgam restorations are more effective in reducing marginal microleakage, particularly at the dentinal margin.

Acid Etching, Dental↗
PubMedDate not supplied

Effect of an "all-in-one" adhesive on pulp blood vessels: a vitalmicroscopic study of rat's teeth.

The newly developed self-etching, self-priming all-in-one adhesives are appealing to clinicians because they are simple and efficient to use. These single-application bonding systems contain chemically active compounds that can alter pulpal blood circulation when applied to deep dentin surfaces. Since adequate microcirculation and oxygenation are the basic requirements for tissue survival, the aim of this study was to investigate the immediate vascular effect of a new self-etching adhesive, Prompt L-Pop/composite and compomer version/(test group). The technique of vitalmicroscopy was used to record the changes in vessel diameter of the first lower incisor of 20 (10-10 in each group) male Sprague-Dawley rats (weighing 315 +/- 74/SE/g) prior to, and at 5, 15, 30 and 60 minutes after the investigated materials were applied to dentin. The application of saline served as the untreated control. The systemic arterial pressure remained unchanged throughout the experiments both in the control (110 +/- 8 mmHg) and in test animals (114 +/- 4 mmHg). In control rats, the diameter of the vessels was stable during the experiment. In the presence of Prompt L-Pop, the diameters decreased significantly during the experimental period (5 minutes: -11.15 +/- 5.03%; 15 minutes: -14.66 +/- 7.71%; 30 minutes: -13.35 +/- 5.79%; 60 minutes: -11.82 +/- 5.63% p < 0.05 in each cases). In this group, stasis developed in pulpal circulation was 1 out of 10 rats. The results from the rat model used in this study suggest that Prompt L-Pop may result in compromised pulpal microcirculation.

Analysis of Variance↗
PubMed2003

In vitro evaluation of different techniques of enamel preparation for pit and fissure sealing.

PURPOSE: To compare the penetration and the imperviousness of two pit and fissure sealants according to surface treatments involving different cleaning procedures with or without subsequent acid etching. MATERIALS AND METHODS: Two sealants were used: a resin-based sealant (Concise White Sealant) and a compomer-based material (Dyract Seal) coupled with an enamel-dentin bonding agent (Dyract Seal and Prime&Bond NT). Extracted molars (n = 120) were randomly divided into 12 groups: 4 control and 8 experimental groups that received different surface treatments. Pumice, alumina, or bicarbonate was used to clean the surfaces. Phosphoric acid or non-rinse conditioner was used as acid etching agents. After sealing, the Concise White Sealant groups were directly thermocycled for 1800 cycles, while the Dyract Seal groups were stored in water for one month before thermocycling. After apex sealing and varnish coating, the fillings were stained with silver nitrate and embedded. Three to 6 cross sections of 200 microm each were made per sample to assess both sealant penetration (% of the length of the fissure) and the imperviousness of the seal (scores method). RESULTS: Concise White Sealant achieves a better enamel sealing than Dyract Seal when the teeth are treated with air abrasion or air polishing followed by etching. Acid etching is essential for good sealing, whatever the material and cleaning technique tested. Only the combination of air abrasion and phosphoric acid etching yielded a leak-free joint. CONCLUSION: This study clearly shows that penetration and sealing are two different phenomena. Ideally, an efficient sealant must have a good sealing ability and a high rate of infiltration as well, but these two properties probably do not have the same clinical relevance. The imperviousness of the seal remains the most important requirement.

Acid Etching, Dental↗
PubMed2004

Comparison of wear and clinical performance between amalgam, composite and open sandwich restorations: 2-year results.

There has been some disquiet over the use of mercury containing restorative materials. The most commonly used alternative is composite resin but this has the potential disadvantage associated with wear and marginal leakage, which in turn, has proven to result in secondary caries and sensitivity. To overcome the shortcomings of a directly placed composite restoration, the glass-ionomer/composite open sandwich technique was introduced followed by the subsequent introduction of compomer systems. The aims of this study were to evaluate the wear and clinical performance of a control group of amalgam restorations compared with that of a group of posterior composite resin restorations fillings and a group of compomer/composite open sandwich restorations placed by a single general dental practitioner. The duration of the study was 2 years. One hundred and thirty three (71.4%) patients were successfully recalled and the wear and clinical performance of each restoration after 6, 12 and 24 months was measured, indirectly. There was no statistically significant difference recorded between the groups at 6 months or 1 year (p > 0.05). However, at the end of the 2-year study, there was a significantly lower rate of wear recorded for the control amalgam restorations compared with other two groups (p = 0.033). There was no statistically significant difference in wear recorded between the two groups of tooth-coloured restorations (p > 0.05). With regards to clinical performance of the restorations, occlusal and proximal contacts in each group of restoration remained satisfactory throughout the study.

Acetone↗
PubMed2004

Influence of the pretreatment of occlusal pits and fissures on the retention of a fissure sealant.

PURPOSE: To evaluate different regimens of enamel conditioning on the retention of a pit and fissure sealant. METHODS: 100 extracted human molars were randomized into 10 experimental groups (n = 10). Conditioning of occlusal pits and fissures was performed with either 37% H3PO4, diamond bur and 37% H3PO4, Er:YAG laser, Er:YAG laser and 37% H3PO4, air abrasion (3 different settings), air abrasion (3 different settings) and subsequent acid etching with 37% H3PO4. 24 hours after placing a compomer-based sealant, the specimens were artificially aged by thermocycling (5/55 degrees C; x1000) and immersed in basic fuchsin dye for another 24 hours. After sectioning, dye penetration along the enamel-resin-interface was determined (% of the fissure depth). Data were statistically analyzed with Kruskal-Wallis H test and Mann-Whitney U test. For qualitative investigations, two further specimens of each group were analyzed in the SEM. RESULTS: Conventional acid etching resulted in significantly superior sealant retention than conditioning with either the Er:YAG laser or air abrasion (irrespective of particle size or air pressure). If mechanical conditioning of the laser or air abrasion was followed by acid-etching, results were statistically equal to the acid-etch only group.

Air Abrasion, Dental↗
PubMedDate not supplied

Penetration and microleakage of dental sealants in artificial fissures.

This study investigated sealant penetration and dye microleakage of a resin composite system, a compomer system, and a resin-modified glass-ionomer cement in artificially grooved fissures in human molars. Ionosit Seal penetrated 99% of the artificial crevices, whereas Dyract Seal penetrated 97%. The penetration of Helioseal F at 90% was statistically different (P<.0001) from the other 2 materials. Microleakage dye penetration occurred in 22% of the Dyract Seal samples, while it occurred in 5% of Healioseal F and 7% of Ionosit Seal samples. The viscosity and flow properties of the 3 sealants allowed the materials to penetrate the artificial grooves, but they did not seem to affect their sealing capacity.

Coloring Agents↗
PubMed2004

Clinical evaluation of four Class 5 restorative materials: 3-year recall.

PURPOSE: To place four restorative materials, including two resin-based composites (Pertac III and Synergy), an improved resin-modified glass-ionomer (Fuji II LC Improved), and a compomer (Dyract AP), in Class 5 non-carious cervical lesions and to evaluate and compare those restorations for marginal discoloration, anatomic form, surface texture, secondary caries, retention, and marginal adaptation at baseline and annually for 3 years. METHODS: The tested materials were used to restore moderate-size Class 5 non-carious cervical lesions. All materials were used following the manufacturers' directions for etching, bonding, curing, and finishing. Thirty restorations of each material were placed. After rubber-dam isolation, a bevel was placed on the occlusal margin of all preparations except the Fuji II LC Improved, and all preparations were cleaned with pumice. Each restorative material was placed and cured in increments except Fuji II LC Improved. All restorations were evaluated at baseline, 6 months, 1, 2, and 3-year recalls using a modified USPHS scale. RESULTS: Analysis with Chi Square and Logit Analysis revealed that, at 3 years, Pertac III and Fuji II LC Improved were significantly rougher than all other materials. Pertac III had significantly poorer marginal adaptation than all other materials. All other comparisons were not significant. At 3-year recall, most restorations were satisfactory.

Acid Etching, Dental↗
PubMedDate not supplied

Effects of aging on mechanical properties of composite restoratives: a depth-sensing microindentation approach.

This study investigated the effects of aging on the hardness and modulus of two composites (Tetric Ceram [TC], Vivadent; Esthet X [EX], Dentsply), a conventional (Compoglass [CG], Vivadent) and a posterior compomer (Dyract Posterior [DP], Dentsply) using a depth-sensing microindentation approach. Seven specimens (3-mm wide x 3-mm long x 2-mm deep) of each material were made and conditioned in distilled water at 37 degrees C. Hardness and modulus of the materials were determined at seven and 30 days using depth-sensing microindentation testing with the Instron MicroTester. Hardness was determined by dividing the peak load over the maximum projected contact area while effective modulus was calculated by analysis of the loading/unloading P-h curves and the analytical model according to Oliver and Pharr (1992). Results were analyzed using one-way ANOVA/Scheffe's post-hoc test and Independent Samples t-test at significance level 0.05. Mean Vickers Hardness (HV) ranged from 46.60 to 58.67 and 44.44 to 59.41 at seven and 30 days, respectively. Mean indentation modulus ranged from 9.57 to 9.95 and 9.19 to 10.03 for the same time periods. At both time periods, EX was significantly harder than all the other materials and HV values for TC were significantly greater than CG. No significant difference in hardness and modulus was observed between seven and 30 days for all materials with the exception of CG. For the latter, a significant decrease in mechanical properties was detected over time.

Analysis of Variance↗
PubMedDate not supplied

Partial ceramic crowns: influence of preparation design and luting material on internal adaptation.

The influence of three different cavity preparations on the marginal integrity of partial ceramic crowns (PCC) luted with four different luting systems was investigated in this in vitro study. PCC preparations were performed in 144 extracted human molars using one of the following preparation designs (n=48/preparation): A--Coverage of functional cusps/butt joint preparation; B--horizontal reduction of functional cusps and C--complete reduction of functional cusps/butt joint preparation. Non-functional cusps were not covered; mesial and distal proximal boxes were extended 1 mm below the cemento-enamel-junction. PCC were fabricated from Vita Mark II ceramic (Vita) with a Cerec 3 Unit (Sirona) and adhesively luted to the cavities using the following luting systems: (VL) Variolink II/Excite (Vivadent), (PA) Panavia F/ED Primer (Kuraray), (DY) Dyract/Prime & Bond NT (DeTrey/Dentsply) and (FU) Fuji Plus/GC Cavity Conditioner (GC). Samples were simultaneously exposed to thermocycling and mechanical loading (TC: 5000x8-55 degrees C, 30 seconds/cycle; ML: 500000x72.5N, 1.6Hz). Marginal adaptation was assessed by evaluating dye penetration on multiple sections by relating the actual penetration distance to the maximal length of the corresponding cavity wall (100%). Ceramic- and tooth-luting material interfaces were evaluated separately. The data were statistically analyzed with the Mann Whitney U-test and Wilcoxon Rank Sumtest. In general, no significant differences could be found between preparations A, B and C. The combination of preparation C and luting material PA showed a tendency for the lowest dye penetration values, especially within dentin (30%). Significant differences could be determined between luting materials: Composite luting materials PA (0%) and VL (1%) revealed less dye penetration than the compomer DY (6%) and resin-modified glass ionomer cement (RMGIC) FU (26%); use of RMGIC caused fractures of the restorations. The dentin/luting material interface showed the highest penetration values, ranging from 17% to 100%. In conclusion, with adhesively bonded partial ceramic crowns, the choice of luting material proved to be more relevant than preparation design under the limitations of this study. Margins below the cemento-enamel junction reveal significant loss of adhesion in spite of subsequent application of adhesive luting techniques. RMGIC cannot be recommended as a luting material for feldspathic PCC.

Acrylic Resins↗
PubMedDate not supplied

Demineralization inhibition of direct tooth-colored restorative materials.

This study compared the demineralization inhibition properties of fluoride releasing tooth-colored restorative materials. Materials evaluated included a giomer (Reactmer, Shofu [RM]), a conventional glass ionomer (Fuji II, GC [FJ]), a resin modified glass ionomer (Fuji II LC, GC [FL]) and a compomer (Dyract AP, Dentsply [DY]). A non-fluoride releasing composite (Spectrum TPH, Dentsply [SP]) was used for comparison. Class V preparations on buccal and palatal/lingual were made at the CEJ of 75 freshly extracted molars. The teeth were randomly divided into five groups of 15 and restored with the various materials. The occlusal half of each restoration was in enamel, while the gingival half was in dentin. The restored teeth were stored in distilled water at 37 degrees C for two weeks and subjected to artificial caries challenge (18 hours demineralization [pH 5.0] followed by six hours of remineralization [pH 7.0]) for three days. Sections of 130 +/- 20 microm were examined with a polarized light microscope, and outer lesion depth [OLD] and wall area [WA] lesion/inhibition measurements were made using image analysis software. All data were subjected to statistical analyses at 0.05 significance level. For the various materials, OLD ranged from 54.55 to 65.86 microm and 124.68 to 145.97 microm in enamel and dentin, respectively. WA ranged from -2356.13 to 1398.20 microm2 and -3011.73 to 5095.80 microm2 (positive values indicate wall inhibition, negative values indicate wall lesion) in enamel and dentin, respectively. Results of ANOVA/Scheffe's post-hoc test (p<0.05) were as follows: Enamel OLD--no significant difference between materials; Dentin OLD--SP > FJ, FL & RM; Enamel WA inhibition--FJ, FL & RM > DY & SP and Dentin WA inhibition--FJ > FL > RM > DY > SP. The demineralization inhibition effect of giomers, conventional and resin-modified glass ionomer cements appear to be more evident at the margins of restorations.

Cariostatic Agents↗
PubMedDate not supplied

Effects of pH on the surface texture of glass ionomer based/containing restorative materials.

This study determined the effect of pH on the surface texture of commonly used posterior glass-ionomer based/containing restorative materials. The materials evaluated included a compomer (Dyract AP), a giomer (Beautifil) and two highly viscous glass ionomer cements (Fuji IX and Ketac Molar). A resin composite (Esthet-X) was used for comparison. Forty-two specimens (3-mm wide x 3-mm long x 2-mm deep) were made for each material. The specimens were divided into six groups and conditioned in the following solutions at 37 degrees C for one week: Citric acid (pH 2, 3, 4, 5 and 6) and distilled water (pH 7). After conditioning, the surface roughness (Ra, microm) of each specimen was measured using a surface profilometer (Surftest, Mitutoyo Corp, Tokyo, Japan). Data was analyzed using one-way ANOVA and Scheffe's test at a significance level of 0.05. The effects of pH on the surface texture of glass-ionomer based/containing restoratives were material dependent. Ra values ranged from 0.02 microm to 0.15 microm and 0.03 microm to 4.40 microm for pH 7 and 2, respectively. With the exception of the composite, the surface roughness of all materials evaluated was significantly affected by acids of low pH. The surface texture of highly viscous glass ionomer cements deteriorated significantly when conditioned in solutions of low pH, which makes them more susceptible to clinical failure.

Analysis of Variance↗