Influence of Light-Curing Glaze and Chlorhexidine Gluconate in the Acrylic Resin Properties: An in situ Study.

This in-situ study aimed to evaluate the chromatic stability, microhardness, and surfacefree energy of chemically activated acrylic resin (CAAR) samples. Eighty CAAR samples were made and each volunteer (n = 20) received two palatal plates with two sides of groups (without and with glaze application). The samples were exposed to two conditions: the control condition (sucrose 30%) and the test condition (sucrose 30% and 0.12% chlorhexidine). The volunteers used the first palatal device (control condition) for seven days and the second palatal device (test condition) for another seven days, with a seven-day break between them. Then, the ΔΕ00, microhardness, and surface-free energy tests were performed. Analysis of Variance and the Tukey test were used (α = 0.05). The control group with glaze showed higher ΔΕ00 compared to the group without the glaze. The test group with glaze had less ΔΕ00 than their respective controls. In both periods, when the glaze was applied, higher microhardness values were found for all groups. Groups with glaze showed lower roughness and higher surface-free energy than groups without the glaze. The values obtained in this study were satisfactory, showing the clinical efficacy of glaze and the use of 0.12% CH for maintaining the physical and mechanical properties of CAAR.

Effect of photopolymerized glaze application on bacterial adhesion on ocular acrylic resin surfaces submitted to accelerated ageing.

Conditions of the acrylic resin (AR) surface, such as roughness, can promote a favourable environment for the adhesion of micro-organisms, even on the surface of ocular prostheses. This study evaluated the influence of photopolymerized glaze application on the roughness of ARs and adhesion of Staphylococcus aureus and Staphylococcus epidermidis on ocular AR surfaces submitted to accelerated ageing. Two hundred and eighty-eight samples of white colour (N1) and colourless ARs were distributed in eight groups (n = 9), based on surface treatments (glaze or ARs submitted to only a final polishing), accelerated ageing (before and after) and periods of microbial growth (24- and 48-h). The roughness average (Ra) and total height of roughness profile (Rt) values were greater for the groups with glaze and increased for all groups after ageing. The microbial adhesion among the groups with and without glaze did not present a statistically significant difference. The ageing did not statistically affect the adhesion of Staph. epidermidis, but affected the adhesion of Staph. aureus, which presented an increase after 24 h of growth on only N1 AR with glaze. These results demonstrate that the glaze did not contribute to adhesion of Staph. aureus and Staph. epidermidis, which are responsible for most ocular prosthetic infections. SIGNIFICANCE AND IMPACT OF THE STUDY: Some recent evidence suggested that the surface finish of ocular prostheses influences the accumulation of deposits that can affect the interaction with pathogenic bacteria, increasing the probability of infections. In addition, surface deterioration over time can increase the roughness and, consequently, biofilm formation. Thus, a better understanding of the influence of surface finish on bacterial adhesion becomes extremely important. In this study, we tested a glaze for surface polishing compared to mechanical polishing, before and after ageing. The results suggest that the glaze did not contribute to microbial adhesion and might be useful in preventing possible prosthetic infections.

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.

Evaluation of the papilla level adjacent to implants placed in fresh, healing or healed sites: A systematic review.

A better understanding of factors that can lead to papilla formation or recession, such as the type of site where the implant was placed, is of fundamental importance to the aesthetic success of the rehabilitation. The aim of this study was to perform a systematic review of the literature regarding the formation or recession of papilla adjacent to implants placed in fresh, healing or healed sites. The protocol for this study was registered in the PROSPERO database (registration number CRD 42016033784). An electronic search was performed by two independent reviewers who applied the inclusion and exclusion criteria on the PubMed/MEDLINE, Scopus, and Embase databases from January 2005 up to February 2016. The initial screening yielded 1,065 articles, from which 15 were selected for a systematic review after applying the inclusion and exclusion criteria. Nine studies compared fresh and healed sites, four studies compared healing and healed sites, one study compared fresh and healing sites, and one study analysed all three sites. The majority of studies identified by this systematic review showed no difference between groups after the longer follow-up period. The sites where the implants were placed did not have a long-term influence on papilla formation or recession.

Are intra-articular injections of hyaluronic acid effective for the treatment of temporomandibular disorders? A systematic review.

This systematic review aimed to investigate whether intra-articular injections of hyaluronic acid (HA) are better than other drugs used in temporomandibular joint arthrocentesis, for the improvement of temporomandibular disorder (TMD) symptoms. Two independent reviewers performed an electronic search of the MEDLINE and Web of Science databases for relevant studies published in English up to March 2016. The key words used included a combination of 'hyaluronic acid', 'viscosupplementation', 'intra-articular injections', 'corticosteroids', or 'non steroidal anti inflammatory agents' with 'temporomandibular disorder'. Selected studies were randomized clinical trials and prospective or retrospective studies that primarily investigated the application of HA injections compared to other intra-articular medications for the treatment of TMD. The initial screening yielded 523 articles. After evaluation of the titles and abstracts, eight were selected. Full texts of these articles were accessed and all fulfilled the inclusion criteria. Intra-articular injections of HA are beneficial in improving the pain and/or functional symptoms of TMDs. However, other drug therapies, such as corticosteroid and non-steroidal anti-inflammatory drug injections, can be used with satisfactory results. Well-designed clinical studies are necessary to identify an adequate protocol, the number of sessions needed, and the appropriate molecular weight of HA for use.