This in vitro study evaluated the effects of delayed versus immediate polishing to permit maturation of interfacial gap-formation around highly viscous conventional glass-ionomer cement (HV-GIC) in Class I restorations, together with determining the associated mechanical properties. Cavity preparations were made on the occlusal surfaces of premolars. Three HV-GICs (Fuji IX GP, GlasIonomer FX-II and Ketac Molar) and one conventional glass-ionomer cement (C-GIC, Fuji II, as a control) were studied, with specimen subgroups (n=10) for each property measured. After polishing, either immediately (six minutes) after setting or after 24 hours storage, the restored teeth were sectioned in a mesiodistal direction through the center of the model Class I restorations. The presence or absence of interfacial-gaps was measured at 1000× magnification at 14 points (each 0.5-mm apart) along the cavity restoration interface (n=10; total points measured per group = 140). Marginal gaps were similarly measured in Teflon molds as swelling data, together with shear-bond-strength to enamel and dentin, flexural strength and moduli. For three HV-GICs and one C-GIC, significant differences (p<0.05) in gap-incidence were observed between polishing immediately and after one-day storage. In the former case, 80–100 gaps were found. In the latter case, only 9–21 gaps were observed. For all materials, their shear-bond-strengths, flexural strength and moduli increased significantly after 24-hour storage.
en-copyright= kn-copyright= en-aut-name=IrieMasao en-aut-sei=Irie en-aut-mei=Masao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MaruoYukinori en-aut-sei=Maruo en-aut-mei=Yukinori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NishgawaGoro en-aut-sei=Nishgawa en-aut-mei=Goro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SuzukiKazuomi en-aut-sei=Suzuki en-aut-mei=Kazuomi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=WattsDavid C en-aut-sei=Watts en-aut-mei=David C kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=University of Manchester Dental School END start-ver=1.4 cd-journal=joma no-vol=22 cd-vols= no-issue=9 article-no= start-page=875 end-page=883 dt-received= dt-revised= dt-accepted= dt-pub-year=2006 dt-pub=20069 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Immediate versus water-storage performance of Class V flowable composite restoratives en-subtitle= kn-subtitle= en-abstract= kn-abstract=Objectives
The aims of this investigation were to clarify the effects of 24 h water-storage and finishing time on mechanical properties and marginal adaptation to a Class V cavity of eight modern flowable resin-composites.
Methods
Eight flowable composites, plus two controls (one microfilled and one hybrid composite), were investigated with specimen sub-groups (n = 10) for each property measured. The principal series of experiments was conducted in model Class V cavities with interfacial polishing either immediately (3 min) after setting or after 24 h water-storage. After the finishing procedure, each tooth was sectioned in a buccolingual direction through the center of the restoration, and the presence or absence of marginal-gaps was measured (and then summed for each cavity) at 14 points (each 0.5 mm apart) along the cavity restoration interface (n = 10 per group; total points measured = 140). The shear bond-strengths to enamel and to dentin, and flexural strengths and moduli data were also measured at 3 min and after 24 h water-storage.
Results
For all flowable composites, polished immediately after setting, 14–30 summed gaps were observed (controls: 64 and 42). For specimens polished after 24 h, a significantly (p < 0.05) reduced number of 8–17 summed gaps occurred for only 3 flowable composites; whereas for 5 flowable composites there were non-significantly-different (p > 0.05) numbers (11–17) of summed gaps (controls: 28 and 22). After 24 h storage, shear bond-strengths to enamel and to dentin, flexural strengths and moduli increased highly significantly (p < 0.001) for all materials, except Silux Plus.
Significance
A post-cure interval of 24 h resulted in enhanced mechanical and adhesive properties of flowable dental composites. In a minority of cases there was also a reduced incidence of marginal-gap formation. However the latter effect may be partly attributed to 24 h delayed polishing, even though such a delay is not usual clinical practice.
Objectives
This in vitro study evaluated the effect on interfacial gap-formation around resin-modified glass–ionomer (RMGIC) root surface restorations with (a) variations in powder/liquid ratio (P/L) of the first increment of an incremental procedure, compared with a bulk restoration technique, and (b) delayed versus immediate polishing, to permit maturation.
Methods
Cavity preparations were placed in premolar teeth on upper facial root surfaces. Two RMGICs were studied (Fuji II LC and Vitremer), with their associated conditioner or primer, applied with an incremental technique. The P/L ratio of the first increment was reduced to fractional (normalized) values between 0.2 and 1.0 of the manufacturers' recommended P/L, and the manufacturers' P/L was used for the second increment. Control groups were bulk filled. After polishing, either: (i) immediately after light-activation or (ii) after 24 h storage, the restored teeth were sectioned in a buccolingual direction through the center of the restoration and the presence or absence of marginal gaps was measured at ×1000 magnification at 14 points (each 0.5-mm apart) along the cavity restoration interface; (n=10; total points measured per group=140).
Results
For both RMGICs, significant differences (p<0.05) in gap-incidence were observed between polishing (i) immediately and (ii) after one-day storage. In the former case, 30–70 gaps were found, with or without the incremental technique. In the latter case, only 2–14 gaps were observed. With fluid mixes (normalized P/L ratios between 0.3 and 0.6) for the first increment, gap-formation was greatly reduced, especially with Fuji II LC.
Significance
To minimize gap formation, more fluid mixes could be used especially with Fuji II LC to give improved adaptation to the dentin. Secondly, whenever possible, polishing should be delayed on the final increment to permit maturation and minimize mechanical disruption of both increments.
Objectives: The purpose of this study was to evaluate the performance of both single and double applications of (Adper Prompt L-Pop) self-etching dental adhesive, when used with three classes of light-activated restorative materials, in comparison to the performance of each restorative system adhesive. Evaluation parameters to be considered for the adhesive systems were (a) immediate marginal adaptation (or gap formation) in tooth cavities, (b) free setting shrinkage-strain determined by the immediate marginal gap-width in a non-bonding Teflon cavity, and (c) their immediate shear bond-strengths to enamel and to dentin.
Methods: The maximum marginal gap-width and the opposing-width (if any) in the tooth cavities and in the Teflon cavities were measured immediately (3 min) after light-activation. The shear bond-strengths to enamel and to dentin were also measured at 3 min.
Results: For light-activated restorative materials during early setting (<3 min), application of Adper Prompt L-Pop exhibited generally superior marginal adaptation to most system adhesives. But there was no additional benefit from double application. The marginal-gaps in tooth cavities and the marginal-gaps in Teflon cavities were highly correlated (r=0.86–0.89, p<0.02–0.01). For enamel and dentin shear bond-strengths, there were no significant differences between single and double applications, for all materials tested except Toughwell and Z 250 with enamel.
Significance: Single application of a self-etch adhesive was a feasible and beneficial alternative to system adhesives for several classes of restorative. Marginal gap-widths in tooth cavities correlated more strongly with free shrinkage-strain magnitudes than with bond-strengths to tooth structure.
en-copyright= kn-copyright= en-aut-name=IrieMasao en-aut-sei=Irie en-aut-mei=Masao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SuzukiKazuomi en-aut-sei=Suzuki en-aut-mei=Kazuomi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=WattsDavid C. en-aut-sei=Watts en-aut-mei=David C. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=University of Manchester en-keyword=Marginal gap formation kn-keyword=Marginal gap formation en-keyword=Bond strength kn-keyword=Bond strength en-keyword=Adhesive technique kn-keyword=Adhesive technique en-keyword=Resin composite kn-keyword=Resin composite en-keyword=Compomer kn-keyword=Compomer END start-ver=1.4 cd-journal=joma no-vol=20 cd-vols= no-issue=1 article-no= start-page=3 end-page=11 dt-received= dt-revised= dt-accepted= dt-pub-year=2004 dt-pub=20041 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Marginal and flexural integrity of three classes of luting cement, with early finishing and water storage en-subtitle= kn-subtitle= en-abstract= kn-abstract=Objectives. The aims of this investigation were to clarify the effects of finishing-time and 24 h water-storage on mechanical properties and marginal adaptation to dentin of seven modern luting cements, representing three chemical types.
Methods. Bistite II, Chemiace II, Compolute, XenoCem, PermaCem, Fuji Cem and Fuji Plus were investigated with specimen sub-groups (N=10) for each property measured. The principal series of experiments was conducted in dentin cavities with interfacial polishing either immediately (3 min) after setting or after 24 h water-storage. After the finishing procedure, the maximum marginal gap width and the opposing width (if any) per cavity were measured microscopically, and summed. Then the overall sum of gap-widths (per group; N=10) was calculated. Marginal gaps were similarly measured in Teflon cavities, together with shear-bond-strengths to dentin and early flexural strengths, moduli and swelling data.
Results. For specimen-sets polished immediately after setting, summed marginal gaps of 23–121 μm were observed, for all luting cements except Compolute. A significantly different (p<0.05) result of either no gap or 6–28 μm summed gap-widths occurred in specimens polished after 24 h. For all materials, their shear-bond-strengths, flexural strength and moduli significantly increased after 24 h storage.
Significance. The marginal behavior can be interpreted in terms of the contributions of bonding, shrinkage, swelling and compliance of components, along with compositional features of the cements. With these types of cement it is generally inadvisable to polish the interfacial luting surface immediately after cementing. The polishing procedures should be carried out not less than 24 h later. One resin-cement was able to withstand immediate finishing.
en-copyright= kn-copyright= en-aut-name=IrieMasao en-aut-sei=Irie en-aut-mei=Masao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SuzukiKazuomi en-aut-sei=Suzuki en-aut-mei=Kazuomi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=WattsDavid C. en-aut-sei=Watts en-aut-mei=David C. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=University of Manchester en-keyword=Luting cement kn-keyword=Luting cement en-keyword=Marginal adaptation kn-keyword=Marginal adaptation en-keyword=Mechanical property kn-keyword=Mechanical property en-keyword=One-day storage kn-keyword=One-day storage END