Search Results (5)

The aim of this in vivo study was to compare total protein present in the salivary films (F) and acquired enamel pellicle (AEP) on eroded and non-eroded surfaces in patients suffering from GORD symptoms with and without GORD diagnosis (GORD, No-GORD). Thirty-nine patients suffering from GORD symptoms and erosive tooth wear on lower first molars and an unaffected posterior occlusal surface in the same quadrant were recruited from Guy’s hospital, London. Salivary film and AEP were collected from the eroded and uneroded occlusal surfaces, using 0.5% sodium dodecyl sulphate (SDS)-soaked filter papers. Total protein concentration was analysed using bicinchoninic acid assay (BCA). Statistical analysis was conducted using Shapiro–Wilk, ANOVA, and Tukey’s tests (p < 0.05), comparing four GDS sample types and GORD vs. No-GORD groups. The level of significance was set as p < 0.05. Data were compared between eroded and uneroded surfaces in the same patient with GORD symptoms, as well as between those with or without a GORD diagnosis (GORD, No-GORD). The AEP total protein concentration from the eroded [2.17 (0.49) mg/mL] and uneroded surfaces [2.24 (0.66) mg/mL] of the GORD group were statistically significantly lower than those on eroded [3.27 (1.01) mg/mL] and uneroded [3.33 (1.57) mg/mL] surfaces in the No-GORD group (p = 0.007) (p = 0.008), respectively. No statistically significant differences were observed for film and AEP between eroded and uneroded surfaces (p > 0.05). Full article

(1) Background: In the oral environment, sound enamel and dental restorative materials are immediately covered by a pellicle layer, which enables bacteria to attach. For the development of new materials with repellent surface functions, information on the formation and maturation of salivary pellicles is crucial. Therefore, the present in situ study aimed to investigate the proteomic profile of salivary pellicles formed on different dental composites. (2) Methods: Light-cured composite and bovine enamel samples (controls) were exposed to the oral cavity for 30, 90, and 120 min. All samples were subjected to optical and mechanical profilometry, as well as SEM surface evaluation. Acquired pellicles and unstimulated whole saliva samples were analyzed by SELDI–TOF–MS. The significance was determined by the generalized estimation equation and the post-hoc bonferroni adjustment. (3) Results: SEM revealed the formation of homogeneous pellicles on all test and control surfaces. Profilometry showed that composite surfaces tend to be of higher roughness compared to enamel. SELDI–TOF–MS detected up to 102 different proteins in the saliva samples and up to 46 proteins in the pellicle. Significant differences among 14 pellicle proteins were found between the composite materials and the controls. (4) Conclusions: Pellicle formation was material- and time-dependent. Proteins differed among the composites and to the control. Full article

Engineering of the acquired enamel pellicle using salivary peptides has been shown to be a promising anticaries strategy. However, the mechanisms by which these peptides protect teeth against tooth decay are not fully understood. In this study, we evaluated the effect of the engineered salivary peptides DR9-DR9 and DR9-RR14 on enamel demineralization in two experimental conditions: (1) adsorbed onto the enamel surface forming the AEP, and (2) forming the AEP combined with their use to treat the biofilms 2×/day, using a validated cariogenic Streptococcus mutans in vitro biofilm model. Biofilms were grown for 144 h on enamel slabs and then collected to determine the bacterial viability (CFU/biofilm) and biofilm mass (mg protein/biofilm), and to extract cellular/extracellular proteins, which were characterized by mass spectrometry. The culture medium was changed 2×/day to fresh medium, and pH (indicator of biofilm acidogenicity) and calcium concentration (indicator of demineralization) was determined in used medium. DR9-RR14 peptide significantly reduced enamel demineralization (p < 0.0001) in both experimental conditions. However, this peptide did not have a significant effect on biofilm biomass (p > 0.05) nor did it modulate the expression of cellular and extracellular bacterial proteins involved in biofilm cariogenicity. These findings suggest that DR9-RR14 may control caries development mainly by a physicochemical mechanism. Full article

Since the modification of the proteinaceous components of the Acquired Enamel Pellicle (AEP) could influence the adhesion of Streptococcus mutans, the most cariogenic bacteria, to dental surfaces, we assessed if engineered salivary peptides would affect the adherence and modulate the bacterial proteome upon adherence. Single-component AEPs were formed onto hydroxyapatite (HAp) discs by incubating them with statherin, histatin-3, DR9, DR9-DR9, DR9-RR14, RR14, and parotid saliva. Then, the discs were inoculated with S. mutans UA159 and the bacteria were allowed to adhere for 2 h, 4 h, and 8 h (n = 12/treatment/time point). The number of bacteria adhered to the HAp discs was determined at each time point and analyzed by two-way ANOVA and Bonferroni tests. Cell-wall proteins were extracted from adhered, planktonic, and inoculum (baseline) bacteria and proteome profiles were obtained after a bottom-up proteomics approach. The number of adhered bacteria significantly increased over time, being the mean values obtained at 8 h, from highest to lowest, as follows: DR9-RR14 > statherin > RR14 = DR9-DR9 > DR9 = histatin3 > saliva (p < 0.05). Treatments modulated the bacterial proteome upon adherence. The findings suggested a potential use of our engineered peptide DR9-DR9 to control S. mutans biofilm development by reducing bacterial colonization. Full article

Immune responses triggered by implant abutment surfaces contributed by surface-adsorbed proteins are critical in clinical implant integration. How material surface-adsorbed proteins relate to host immune responses remain unclear. This study aimed to profile and address the immunological roles of surface-adsorbed salivary proteins on conventional implant abutment materials. Standardized polished bocks (5 × 5 × 1 mm³) were prepared from titanium and feldspathic ceramic. Salivary acquired pellicle formed in vitro was examined by liquid chromatography-tandem mass spectrometry and gene ontology (GO) analysis to identify and characterize the adsorbed proteins. Out of 759 proteins identified from pooled saliva samples, 396 were found to be attached to the two materials tested—369 on titanium and 298 on ceramic, with 281 common to both. GO annotation of immune processes was undertaken to form a protein–protein interaction network, and 14 hub proteins (≥6 interaction partners) (coding genes: B2M, C3, CLU, DEFA1, HSP90AA1, HSP90AB1, LTF, PIGR, PSMA2, RAC1, RAP1A, S100A8, S100A9, and SLP1) were identified as the key proteins connecting multiple (6–9) immune processes. The results offered putative immunological prospects of implant abutment material surface-adsorbed salivary proteins, which could potentially underpin the dynamic nature of implant–mucosal/implant–microbial interactions. Full article