Is surface roughness of direct resin composite restorations material and polisher-dependent? A systematic review

Awareness of possible complications associated with direct composite restorations: A multinational survey among dentists from 13 countries with meta-analysis

OBJECTIVES

Resin-based composites (RBCs) evolved into favoured materials for teeth restorations, marking a significant change in dental practice. Despite many advantages, RBCs exhibit various limitations in their physical and chemical properties. Therefore, we assessed the dentists' awareness of possible complications after direct composite restorations and their opinions about this material.

METHODS

The online questionnaire was created in English in May 2023. A 16-item survey was dedicated to general dentists and specialists. The first section included four questions related to demographic characteristics. The second section comprised twelve questions and focused on awareness of potential side effects of composite restorations, the most crucial advantages and disadvantages of composite resins, and the frequency of experienced clinical complications after the application of composite materials.

RESULTS

A total of 1830 dentists from 13 countries took part in the survey. Dentists most often declared awareness of low adhesion to the dentine (77.5 %) and, most rarely, solubility in oral fluids (42.6 %). Aesthetics was identified as the main advantage of composite fillings (79 %), followed by the possibility of repair (59 %) and adhesion to enamel (57 %). Polymerisation shrinkage was a major disadvantage for most countries (70 % overall). Analysing the declared potential clinical complications for all countries, statistically significant findings were obtained for marginal discolouration (OR=2.982, 95 % CI: 1.321-6.730, p-value=0.009) and borderline significance for secondary caries (OR=1.814, 95 % CI: 0.964-3.415, p-value=0.065).

CONCLUSIONS

Dentists value aesthetics and repairability but are aware of shrinkage and experience discolouration. The issue of toxicity and solubility seems to be the least known to dentists.

CLINICAL SIGNIFICANCE

Dentists should use RBCs with critical caution due to possible side effects. Despite the undoubted aesthetics of direct composite restorations, it is necessary to remember potential clinical complications such as marginal discolouration or secondary caries.

In vitro comparison of one-step, two-step, and three-step polishing systems on the surface roughness and gloss of different resin composites

OBJECTIVES

This laboratory study evaluated the effect of three polishing systems on the surface roughness and gloss of resin composites.

MATERIALS AND METHODS

Thirty specimens (6 mm Ø × 8 mm) were fabricated from each of three resin composites: Z 350 XT (nanofill), Harmonize (nanohybrid), and Estelite Omega (supranonofill). All specimens were photopolymerized using a multi-peak LED curing unit (VALO-Standard mode), having a exitance irradiance of approximately 1000 mW/cm2 against a polyester strip (PS). 2 mm was then removed from the irradiated end (finished) using #320 abrasive paper (F). Specimens were then randomly polished (P) using a one-step (1S) (OneGloss), two-step (2S) (EVE Diacomp Twist Basic CA), or 3-step (3S) (Astropol P) system (n = 10). For PS, F, and P groups, surface roughness (Ra) was measured using a surface roughness tester, and surface gloss was measured with a glossmeter. For each specimen, the percent recovery to the PS value (%R) of surface roughness and surface gloss were calculated. Data were analyzed using two-way ANOVA, followed by Tukey's test. Surface roughness and gloss values were submitted to Pearson's correlation test (α = 0.05). All statistical testing was performed using a pre-set alpha of 0.05.

RESULTS

The interaction term [resin composite × polishing system] was significant for both surface roughness (p = 0.001) and gloss (p = 0.0001). For all resin composites, the 2S and 3S systems provided a higher %R of surface roughness and gloss compared to those of the 1S system. There was a negative correlation between surface roughness and gloss, but only a few combinations showed strong correlations.

CONCLUSIONS

The 2S and 3S polishing systems provided surfaces having greater smoothness and gloss compared to the 1S system. The ability to recover surface roughness and gloss was dependent on type of resin composite filler classification.

CLINICAL SIGNIFICANCE

The 3S and 2S polishing systems were more effective in achieving PS values than was the 1S system for all tested resin composites. However, individual polishing systems performed differently depending on type of resin composite.