Analysis of Biofilm Adhesion on CAD/CAM Lithium Disilicates Under Different Types of Intraoral Polishing.

PURPOSE: To evaluate the adhesion of Streptococcus mutans (S. mutans) on lithium disilicate ceramics, submitted to different intraoral polishing protocols, and the degree of surface smoothness obtained. MATERIALS AND METHODS: Fifty lithium disilicate specimens were divided into 5 groups (n=10): G1-Glaze Group (positive control); G2-Glaze Group + Wear + Glaze; G3-Wear Group (negative control); G4-Ceramisté Wear Group; G5-Optrafine Wear Group. Surface roughness (Ra - µm) was evaluated and the surface characteristics were assessed using a scanning electron microscope (SEM); to assess S. mutans biofilm, the number of cultured cells was evaluated by counting colony-forming units (CFU/mL). The data underwent one-way ANOVA followed by Tukey's test (P⟨.05). RESULTS: There was a significant difference in the surface roughness of all groups compared with G3. There was no significant difference between the G4 and G5 groups that received polishing. G1 group had the lowest mean roughness values. There was a difference in Log values (CFU/mL) between the G3 group and the groups that received glaze (G1 and G2). The G3 group had the highest adhesion of S. mutans (4.53 Log). CONCLUSION: The most effective polishing protocol after wear is glazing, presenting the lowest roughness and CFU/mL values.

Microbiological analysis of conjunctival secretion in anophthalmic cavity, contralateral eye and ocular prosthesis of patients with maxillofacial abnormalities.

The purpose of this study was to identify and analyse the micro-organisms present in the conjunctival secretion in anophthalmic cavities of wearers of ocular prostheses, as well as on the prostheses used by them, correlating them with the microbiota of the contralateral eye. Nine patients with maxillofacial abnormalities, wearers of an acrylic resin ocular prosthesis participated in the study. Collections of conjunctival secretions and biofilm were performed on the prosthesis, anophthalmic cavity and contralateral eye for the mycological and bacterial analyses. The data were submitted to statistical analysis, performing a Kendall correlation test to identify the correlation between the collection site and the identified micro-organism (P < 0·05). It was verified that the most prevalent micro-organisms were the Staphylococcus aureus and Staphylococcus epidermidis, independent of the collection site, and that negative cultures for fungi were encountered in 85·2% of collections, independent of the region. It was not possible to establish a correlation among the types of micro-organisms and the collection sites. SIGNIFICANCE AND IMPACT OF THE STUDY: Some evidence suggests that the surface roughness of ocular prostheses can influence interactions with micro-organisms, with greater prejudicial consequences, such as the establishment of biofilms, which could lead to infections. Thus, it becomes extremely important to identify the micro-organisms present on the acrylic surfaces of ocular prostheses, as well as the microbiota of the anophthalmic cavity and contralateral eye of wearers of the same, so that subsequent control measures promote the homeostatic maintenance of the ocular region.