Objectives To evaluate the surface roughness and gloss of three nanohybrid resin composites after polishing with three different polishing systems. Materials and Methods A total number of 112 disc specimens (10 × 3 mm) were prepared from nanohybrid—Empress Direct (ID), Grandio (GR), Filtek Z350 (Z350) and a microhybrid resin composite restorative materials—Filtek Z250 (Z250). Following 24-hour storage in 37°C distilled water, each composite group (n = 28) was assigned into four groups (n = 7) according to finishing/polishing (F/P) system: Mylar strip, Optrapol, Politip, and Sof-Lex (SL). The surface roughness (Ra, mm) was measured by a novel three-dimensional method using an image analysis software attached to an environmental scanning electron microscope. A glossometer was used to measure the surface gloss. Results Statistical analysis used was ANOVA test. Two-way Anova test revealed that the “type of composite” and “F/P techniques” had a significant effect on both surface roughness and gloss of the tested resin composite materials (p < 0.05). Tukey’s post hoc test showed that ID, GR, and Z350 revealed lower surface roughness and higher surface gloss than Z250 within the same polishing system (p < 0.05). Sof-Lex polishing discs produced the lowest surface roughness and highest surface gloss values compared with Optrapol and Politip (p < 0.05). Conclusion The tested F/P systems provided comparable surface roughness and gloss for nanohybrid composites. The Sof-Lex system provided the best surface roughness and gloss for nanohybrid composites.
Objectives This randomized clinical trial aimed to evaluate clinical outcomes of two types of esthetic crowns fabricated using a three-dimensional (3D) dental printer and computer-aided design and manufacturing (CAD/CAM) system as an alternative full-coronal restoration for extensively carious pulp-treated primary molars. Materials and Methods Randomization was done for 50 lower primary molars in 50 child patients, split into two groups based on the fabrication method used: Group A: CAD/CAM crowns using polymethyl methacrylate (PMMA) blocks and Group B: 3D dental printed crowns using GC photopolymer resin. All crowns were evaluated at baseline and at 3rd, 6th, and 12th months using the U.S. Public Health Service criteria for gingival health, retention, and marginal integrity for both groups. Statistical Analysis The survival rate of 3D-printable crowns was 84% compared with 80% survival rate using CAD/CAM fabricated crowns at the end of the 12th-month follow-up. No statistically significant differences were noted in restoration failure. In the evaluation of gingival health between the two groups’ follow-up times, no statistically significant differences were noted at the 3rd- and 6th-month follow-ups, yet at the 12th month, statistically significant differences were noted (p = 0.022) when comparing gingival health. No statistically significant differences were noted between the two groups when comparing marginal integrity scores in all the follow-up periods. Conclusion Resin crowns fabricated via 3D dental printer and PMMA crowns fabricated using CAD/CAM are acceptable esthetic choices in restoring pulp-treated primary molars with great marginal integrity and crowns retention. 3D-printed resin crowns showed less cementing failure and performed better regarding gingival response compared with PMMA crowns.
Prefabricated zirconia crowns are available to treat anterior and posterior primary teeth, which possess high resistance, long durability, and short working time. They are also esthetic and available in various sizes for all primary teeth. However, their high costs can present a clear disadvantage in many communities around the world. This random clinical trial study sample included 63 crowns (31 CCZC, 32 NZC) applied to 44 children aged five to nine years with zirconia crowns placed on anterior or posterior primary teeth. Group (1): Locally manufactured crowns were created with different measurements by using CAD/CAM (CCZC) and Group (2): NuSmile® zirconia crowns (NZC). Glass ionomer cement was used to cement all crowns. The children were followed-up at one, three, and six months, using oral hygiene index-simplified (OHI–S), gingival index (GI), plaque index (PI), bleeding on probing (BOP), and crown margin extension. Statistical analyses used: Mann-Whitney U test, Friedman test, and Wilcoxon test. This study showed that CCZC did not cause gingival changes after crown application in clinical tissue appearance, bleeding, and gingival recession. Reduced plaque accumulation was observed during follow-up periods. Finally, there was no statistically significant difference between CCZC and NZC, according to this study. CCZCs are a convenient and economical option to achieve esthetic, healthy, and functional aspects during restoring primary teeth.
1 March 2022 in Journal of Evidence-Based Dental Practice