ABSTRACT
Background:
Beverage consumption is commonly practiced by individuals of all age groups and is likewise known to cause pH alteration of the oral cavity, thereby, affecting the physical property of the restorative material like surface roughness.
Aim:
To assess surface roughness changes in four resin-based restorative materials (Ormocer, Giomer, Nanoceramic, and Nanohybrid composite) after exposure to commonly consumed beverages.
Materials and Methods:
Two hundred composite discs were divided into four groups (Giomer, Ormocer, Nanoceramic, and Nanohybrid) and immersed in five subgroups (artificial saliva, carbonated beverage, carbonated fruit-based beverage, non-carbonated fruit-based beverage, and black coffee) for 21 days. Surface roughness was measured using a surface profilometer, and statistical analysis was performed using ANOVA and Tukey’s test.
Results:
Nanohybrid (Group 4) exposed to carbonated beverages showed the highest roughness (Ra = 2.439 ± 0.797 μm). Nanoceramic (Group 3) exhibited the lowest roughness (Ra = 1.537 ± 0.305 mm), demonstrating superior resistance to surface degradation.
Conclusion:
Nanoceramic composite resin showed the least surface roughness changes and was highly resistant against all erosive beverages.
KEYWORDS: Aesthetic restorative materials, beverages, nanoceramic, profilometer, surface roughness
INTRODUCTION
Aesthetic dentistry has advanced with innovative materials like Giomers, Ormocers, Nanoceramics, and Nanohybrids, offering enhanced aesthetics, durability, and fluoride release. However, composite restorations face challenges from intrinsic factors (e.g., reflux, bulimia) and extrinsic factors (e.g., acidic foods, beverages, and medications) that degrade material properties.[1] Acidic exposure can increase wear, surface roughness, and pigmentation, impacting aesthetics, patient comfort, and periodontal health.[2] Given the critical role of surface texture in restoration longevity and plaque accumulation, this study evaluates the effects of commonly consumed beverages on the surface roughness of composite materials under simulated oral conditions.
MATERIALS AND METHODS
Two hundred circular disc-shaped samples (5 mm diameter, 2 mm thickness) were fabricated using four composite materials: Group 1: Giomer, Group 2: Ormocer, Group 3: Nanoceramic, and Group 4: Nanohybrid (n = 50/group). A customized Teflon mold with a mylar strip was used for the smoothest surface. Discs were polymerized with a LED curing light (1250 mW/cm2), followed by post-curing and storage in distilled water at 37°C for 24 hours.
Each group was further divided into five subgroups based on the immersion medium: Subgroup A: Artificial saliva, Subgroup B: Carbonated beverage (Coca-Cola), Subgroup C: Carbonated fruit beverage (Appy Fizz), Subgroup D: Non-carbonated fruit-based beverage (Tropicana Orange), and Subgroup E: Black coffee. Samples were immersed in the assigned beverage for 16 hours daily, alternating with 8 hours in artificial saliva, over 21 days. Surface roughness was measured using a profilometer (SJ-201, Mitutoyo, Japan), with surface roughness (Ra) values calculated from three readings per sample. Data were analyzed using one-way ANOVA and post hoc Tukey’s tests, with significance set at P < 0.05.
RESULTS
The mean surface roughness and intergroup comparison after immersion in the beverages are summarized in Table 1.
Table 1.
Intergroup comparison of mean surface roughness (Ra in μm) of various restorative restorative materials on exposure to various beverages
| Group | Subgroup A | Subgroup B | Subgroup C | Subgroup D | Subgroup E |
|---|---|---|---|---|---|
| Giomer | 0.793±0.166 | 2.276±0.380 | 1.746±0.151 | 1.177±0.090 | 1.118±0.110 |
| Ormocer | 0.707±0.121 | 1.990±0.222 | 1.575±0.257 | 1.167±0.079 | 0.867±0.126 |
| Nanoceramic | 0.711±0.119 | 1.537±0.305 | 1.235±0.657 | 1.017±0.979 | 0.816±0.153 |
| Nanohybrid | 0.756±0.108 | 2.439±0.797 | 1.790±0.304 | 1.200±0.081 | 0.891±0.075 |
| P | 0.423 | 0.001* | 0.134 | 0.000* | 0.000* |
*P<0.05 – Significant
DISCUSSION
In restorative dentistry, achieving smooth surfaces with minimal porosity is essential for reduced bacterial plaque accumulation and improved aesthetics. Surface roughness significantly affects optical properties, wear resistance, and adhesion of foreign materials, making its evaluation critical. Due to the complexity of intraoral conditions, an in vitro model was employed to simulate the oral environment, enabling controlled analysis of saliva and beverage effects on composites. Profilometer was chosen for its sensitivity in detecting early surface degradation. Ra values, representing the mean height of surface irregularities in microns (μm), were analyzed as indicators of material smoothness.
Given the high global consumption of soft drinks and fruit juices, the beverages tested included carbonated, carbonated fruit-based, non-carbonated fruit-based, and black coffee, alongside artificial saliva as a control. Specimens were immersed for 16 hours daily in beverages, followed by 8 hours in saliva for 21 days, simulating oral exposure and salivary buffering.[3,4]
Findings revealed that carbonated beverages exhibited the highest surface roughness, causing significant erosion due to their acidic content, particularly orthophosphoric acid. Subgroup comparisons showed that Coca-Cola caused the greatest surface degradation across all groups. Artificial saliva and black coffee resulted in the least roughness, attributed to saliva’s protective buffering and coffee’s amino acid content.
Among the materials, Nanoceramic composites demonstrated the lowest roughness, attributed to pre-polymerized spherical fillers, silane coupling agents, and hydrolytic stability. In contrast, Nanohybrid composites showed the highest roughness due to their higher organic content and susceptibility to water sorption. Statistical analysis confirmed significant differences (P < 0.05) in Ra values between groups and subgroups, with the following order of erosion: Carbonated beverage > Carbonated fruit-based beverage > Non-carbonated fruit-based beverage > Black coffee > Artificial saliva. The study highlights that composite material composition and filler properties influence surface durability, with Nanoceramic emerging as the most resistant to beverage-induced degradation. These findings support its use in clinical settings requiring enhanced longevity and aesthetic outcomes in restorative materials.
da Silva MA et al.,[5] Wongkhantee et al.,[1] and Kitchens and Owens[6] all corroborated the higher surface roughness values observed in restorative materials immersed in carbonated beverages, which is consistent with this study’s results. Studies by O’Brien and Yee,[7] Sarkar,[2] and Nagem Filho et al.[8] support the mechanisms of resin matrix degradation and filler particle dislodgment, which explains the increase in surface roughness. Furthermore, Ferracane[9] supports the choice of immersion duration, highlighting that saturation in composite materials occurs over 7–60 days, while Söderholm et al.[10] observed resin-filler hydrolysis and microcracks leading to increased roughness, aligning with this study’s findings. Additionally, Bagheri et al.[11] and Valinoti et al.[12] found that nanoceramic composites exhibited superior resistance to surface degradation, attributing this to their filler content and chemical bonding stability, which is reflected in the findings of this study. In contrast, von Fraunhofer and Rogers[13] discussed the challenges of replicating enamel dissolution caused by beverages, supporting the rationale for using an in vitro approach in this study. Ionta et al.[14] highlighted the impact of artificial saliva on surface roughness due to its remineralizing properties, which is consistent with the results observed in the control group.
The study’s limitations include in vitro settings, where changes in surface roughness may weaken the material, unlike in vivo conditions where composites are exposed to a mix of food and beverages with saliva. Beverages were tested undiluted, whereas, in the oral cavity, they mix with saliva, raising pH and reducing erosive effects. Further studies are needed to assess the impact of these beverages on the clinical integrity of teeth and restorative materials.
CONCLUSION
All composite materials showed increased surface roughness upon exposure to artificial saliva and acidic beverages. Nanohybrid composites had the highest surface roughness, while nanoceramics showed the greatest resistance to degradation. Beverages with lower pH, particularly carbonated and carbonated fruit-based drinks, caused the most erosion. This highlights the detrimental impact of acidic beverages on the surface integrity of dental restorations and tooth structure.
Conflicts of interest
There are no conflicts of interest.
Funding Statement
Nil.
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