Dental polymers are now available as monolithic materials which can be readily used in computer-aided design and computer-aided manufacturing (CAD/CAM) systems. Despite possessing numerous advantages over conventionally produced polymers, the polymers produced by either of these systems fail to exhibit immunity to surface microbial adhesion when introduced into the oral environment, leading to the development of oral diseases. The aim of this study was to analyze the biofilm formation of six microorganisms from the oral cavity and its correlation to the surface characteristics of CAD/CAM dental polymers. A total of ninety specimens were divided into three groups: resin-based composite, polymethyl methacrylate, and polyether ether ketone. The experimental procedure included surface roughness and water contact angle measurements, colony forming unit counting, and scanning electron microscopy analysis of biofilm formed on the surface of the tested materials. The data were analyzed using the Kruskal–Wallis test, with a Dunn’s post hoc analysis, and one way analysis of variance, with a Tukey’s post hoc test; the correlation between the measurements was tested using Spearman’s correlation coefficient, and descriptive statistics were used to present the data. Despite using the same manufacturing procedure, as well as the identical manufacturer’s finishing and polishing protocols, CAD/CAM dental polymers revealed significant differences in surface roughness and water contact angle, and the increased values of both parameters led to an increase in biofilm formation on the surface of the materials. The CAD/CAM resin-based composite showed the lowest number of adhered microorganisms compared to CAD/CAM polymethyl methacrylate and CAD/CAM polyether ether ketone.
30 December 2022 in European Journal of Oral Sciences
Background and Objectives: Caries development is associated with poor oral hygiene, inadequate dietary habits, quantitative and qualitative food content, and a high level of bacterial plaque. Physical and chemical changes in saliva composition and particularly changes in its buffering capability play a significant role in caries development. This study aimed to determine the predictors of poor oral health among a sample of second-year dental students. Materials and Methods: The oral health of students was estimated with clinical examination and the DMFT index. The interview included questions about demographics status (gender, age), a dietary habits questionnaire, questions about oral hygiene, and a demonstration of tooth brushing technique. Unstimulated saliva samples were collected to measure buffering capacity and pH. Results: Almost half of the students have a low level of caries experience (46.7%), followed by a slightly smaller number having a medium level (41.3%), while one in eight students (12.0%) demonstrates a high level of caries experience. Male students have a statistically higher DMFT index 5.7 ± 1.2 than female participants 4.5 ± 0.5 (p = 0.036). Significant predictors for the DMFT index score in students were milk [β-coefficient = −0.338, p = 0.011] and yoghurt [β-coefficient = 0.284, p = 0.040] consumption. All students brushed their teeth two or more times during the day, usually after waking up before breakfast and before bedtime. Most students (85.3%) apply the proper tooth brushing technique, with female students applying it more frequently (p = 0.038). The mean salivary pH was 6.9, while the mean buffer capacity was 5.8. Female respondents have a statistically lower buffer capacity (5.8 ± 0.5) than male respondents (6.1 ± 0.4) (p = 0.047). Conclusions: Dentistry students are introduced to good oral hygiene habits, especially female students, while dietary habits should be improved. However, one in eight dental students is at high caries risk. By assessing the level of caries experience, targeted strategies can be developed to promote, maintain, and enhance oral health among dental students.
Purpose: To evaluate the surface characteristics of hybrid ceramic-polymer materials before and after exposure to erosive and abrasive media.Methods: Samples were prepared from Vita Enamic (VE), Cerasmart (CS), VarseoSmile Crown plus (VSC), and VarseoSmile Temp (VST). Surface roughness (SR), scanning electron microscopy (SEM), and surface hardness (SH) analyses were performed before (T0) and after exposing the samples to gastric juice (GJ), toothbrushing (TB), or both (GJ TB) for a simulated period of one (T1) or two years (T2).Results: At T0, VSC and VST showed higher average (Ra) and maximum (Rz) roughness values, more homogeneous surfaces in SEM micrographs, and lower Vickers numbers (HV) than VE and CS. At T1 and T2, samples showed higher Ra values, greater surface damage on SEM micrographs, and reduced HV. The most pronounced changes were evident for GJ TB samples, followed in order by GJ (within VE and CS) and TB samples (within VSC and VST).Conclusion: VE and CS showed initially lower SR and higher SH, lower resistance to GJ, and higher resistance to TB than VSC and VST, which would be essential when fabricating restorations for patients who are particularly susceptible to dental erosion and abrasion.
Background/Objectives: Dental caries, one of the most common oral diseases worldwide, represents a major public health concern. Contemporary dentistry has established several non-invasive approaches and resin infiltration, as a micro-invasive path, in the treatment of white spot lesions (WSLs). This study aimed to evaluate the effect of different WSL treatments on enamel surface microhardness. Materials and Methods: Seventy-five intact human premolars extracted upon orthodontic indication and the demineralizing solution composed of acetic acid, monopotassium phosphate and calcium chloride with pH = 4.4 and exposure time 96 h were used. The samples were randomly divided into five groups (n = 15): I—intact enamel (control group); II—artificial white spot lesion; III—artificial WSL treated with fluoride varnish; IV—artificial WSL treated with casein phosphopeptide—amorphous calcium phosphate (CPP-ACP) paste; V—resin-infiltrated artificial WSL. The surface microhardness was determined using the Oliver–Pharr method and a spherical indenter (Shimadzu Indenter, Kyoto, Japan). One-way analysis of variance (ANOVA) followed by a Post Hoc test (Bonferroni) was used with a level of significance set at p < 0.05. Results: Resin-infiltrated white spot lesions showed comparable microhardness mean value as the control group: 68.23 (±21.45) and 63.57 (±18.89), respectively (p > 0.05). Also, resin infiltration increased enamel microhardness compared to WSL values, with a statistically significant difference (p < 0.05). Fluoride varnish and CPP-ACP treatment resulted in equivalent values (50.84 ± 14.35 and 50.99 ± 15.31, respectively). Conclusions: Different WSL treatments (fluoride varnish, CPP-ACP and resin infiltration) produced comparable enamel microhardness values. Among the tested agents, resin infiltration resulted in higher microhardness values, while fluoride varnish and CPP-ACP demonstrated equivalent outcomes.