ABSTRACT High viscous glass ionomer cement (HVGIC) was recently developed for atraumatic restorative treatment (ART). However, its moisture sensitivity remains a limitation thus protective coating application is recommended. This study investigated the effect of resin coating on the surface roughness and microhardness of two HVGICs (Riva Self Cure HVGIC [RV] and Equia® Forte Fil [EQ]) conditioned in food-simulating liquids (FSLs). Fifty standard disc-shaped samples were fabricated using customised stainless-steel mould (10 × 2 mm). Coating was applied on top surface of all samples and subsequently divided into five groups: air (control), distilled water, 0.02 N citric acid, heptane and 50% ethanol-water solution. The samples were conditioned in FSLs at 37°C for seven days. Subsequently, the surface roughness and microhardness of samples were measured using optical profilometry and microhardness tester, respectively. SEM analysis was done for qualitative observation of surface morphological changes. Data were analysed using one-way ANOVA, two-way ANOVA and posthoc Tukey’s test (α = 0.05). Interestingly, the results revealed that surface roughness was significantly influenced by FSLs immersion, presence of coating and the materials itself (p < 0.001). The lowest surface roughness was found on control coated samples: RV (50.98±4.25) nm and EQ (62.77±3.92) nm, while the highest values seen on uncoated surfaces in citric acid: RV (505.26±31.10) nm and EQ (350.33±15.36) nm. RV samples had the lowest microhardness of 54.97±2.48 Vickers hardness number (VHN) post-immersion in citric acid. In conclusion, with the exception of RV conditioned in heptane and ethanol, the uncoated HVGICs generally had higher surface roughness than the coated HVGICs. HVGICs conditioned in citric acid showed the most significant increase in surface roughness and reduction in microhardness.
Glass Ionomer Cements--adverse effects

OBJECTIVETo investigate the resin-modified glass ionomer cement for inhibition of enamel demineralization adjacent to orthodontic brackets under a pH cycling experiment.

METHODSThe study used 5 pairs of extracted human premolars. The experiment teeth were bonded with resin-modified glass ionomer, the control teeth were bonded with composite resin. All samples were under the pH cycling experiment each day for 60 days. Demineralization lesions of enamel adjacent to orthodontic brackets were evaluated with polarized light microscopy. The depth and area of the lesion, and the distance between the edge of the adhesive on the enamel surface and the border of the lesion were measured.

RESULTSThe depth and area of lesions of control were greater than those of experiment group were. Paired t test showed significant differences (p < 0.001). There was always a distance between the lesions border and the glass ionomer cement. In control group, all lesions were developed under the edge of composite resin.

CONCLUSIONIt was suggested that resin-modified glass ionomer may become an orthodontic bonding agent to minimize enamel demineralization.

Glass Ionomer Cements ; chemistry ; Humans ; In Vitro Techniques ; Orthodontic Brackets ; adverse effects ; Tooth Demineralization ; etiology ; prevention & control

OBJECTIVETo prove the inhibitory effect of glass ionomer cement for orthodontic bonding on bacteria.

METHODSTwenty-two persons were chosen randomly. In vivo, with the split-mouth technique, brackets were bonded with glass ionomer cement or composite resin respectively. Plaque samples were taken from the area of the adhesive one month after the placement of brackets and incubated for microbiologic analysis.

RESULTSThere was no significant difference in the amount of total anaerobic bacteria with the two materials. There were also no obvious reduction of the numbers of S. mutans (the composite: 2.4 x 10(10) CFU/L, the glass ionomer cement: 2.8 x 10(10) CFU/L, P = 0.673) and its proportion (percentage of total CFU) with the use of glass ionomer cement compared with the composite.

CONCLUSIONSThere was no long term inhibitory effect on bacteria adjacent to glass ionomer cement for orthodontic bonding.

Adolescent ; Child ; Composite Resins ; pharmacology ; Dental Plaque ; microbiology ; Female ; Glass Ionomer Cements ; pharmacology ; Humans ; Lactobacillus ; drug effects ; Male ; Orthodontic Brackets ; adverse effects ; Streptococcus mutans ; drug effects

OBJECTIVETo evaluate the clinical effects of filling for radiation carious cavities.

METHODS146 carious cavities of 15 patients after radiotherapy for head and neck malignancies were included and were filled with two new GIC (Ketac-Molar and Fuji IX). The 2 years follow-up results were evaluated with USPHS evaluation criterion.

RESULTS(1) The 2 years excellent rates were 51.7% in Ketac-Molar and 52.3% in Fuji IX, no significant differences. (2) Failures and defects were mainly occurred after 1 and 2 years. The main reason of failure was loss of filling. Marginal staining was a common shortcoming of the two materials. (3) There were no significant differences in main indexes except retention.

CONCLUSIONSIt is successful for radiation caries to be filled with Ketac-molar and Fuji IX, and is practically significant in stomatological clinic.

Adult ; Aged ; Cranial Irradiation ; adverse effects ; Dental Caries ; etiology ; pathology ; therapy ; Dental Restoration, Permanent ; methods ; statistics & numerical data ; Female ; Follow-Up Studies ; Glass Ionomer Cements ; Head and Neck Neoplasms ; radiotherapy ; Humans ; Male ; Middle Aged ; Time Factors ; Treatment Outcome