polishing Dotaz Zobrazit nápovědu

Cíl studie. Cílem prospektivní studie bylo zhodnotit dlouhodobý efekt odstranění LEC (lens epithelial cells) mechanickým čištěním pouzdra čočky na vznik opacit předního pouzdra (anterior capsule opacification, ACO) a na rozvoj opacit zadního pouzdra (posterior capsule opacification, PCO). Metodika a soubor. Do studie bylo zařazeno celkem 28 pacientů s průměrným věkem 57 let (27 až 87 let), kteří podstoupili operaci katarakty obou očí. Z 28 pacientů se k vyšetření po dvou a více letech dostavilo 23. Pro irigaci a aspiraci zbytků čočkových hmot po fakoemulzifikaci byla použita bimanuální (nově také označovaná jako biaxiální) irigace/aspirace ze dvou pomocných 1mm širokých protilehlých incizí (od č. 3 a 9). U každého pacienta bylo čočkové pouzdro jednoho oka v maximální mydriáze mechanicky čištěno (nejméně 5 minut) speciálně zkonstruovanou 5d (5dírkovou) aspirační kanylou určenou zejména k aspiraci LEC z oblasti ekvátoru. Přední list byl zbaven LEC standardní jednodírkovou aspirační kanylou. U druhého oka téhož pacienta byly LEC předního pouzdra a ekvátoru ponechány intaktní. Do obou očí byla implantována stejná nitrooční čočka. Kontrola v odstupu více jak 2 let od operace zahrnovala biomikroskopické vyšetření, pořízení fotografie intraokulární čočky a pouzdra čočky v retroiluminaci a vyšetření předního segmentu Scheimpflugovou kamerou (Pentacam) se změřením denzity předního a zadního pouzdra čočky. Ke statistickému zhodnocení výsledků byl použit Wilcoxonův párový test. Výsledky. Dle objektivní denzitometrie pomocí systému Pentacam byla zjištěna statisticky signifikantně nižší denzita předního pouzdra u očí, u kterých bylo peroperačně mechanicky vyčištěno čočkové pouzdro včetně ekvátoru a předního listu. V míře denzit zadního pouzdra nebyly mezi oběma očima nalezeny statisticky významné odchylky přesto, že u 43 % pacientů bylo na oku s čištěným pouzdrem vizuálně menší zakalení zadního pouzdra. Závěr. Na základě získaných výsledků lze konstatovat, že mechanické čištění pouzdra čočky včetně ekvátoru a předního pouzdra vede k prokazatelně nižší míře opacit předního pouzdra (ACO), ale nemá statisticky významný vliv na rozvoj opacit zadního pouzdra (PCO).

Aim: The aim of the prospective study was to evaluate the long-term effect of the lens epithelial cells (LEC) removal by means of the lens capsule mechanical polishing on the development of the anterior capsule opacification (ACO) and posterior capsule opacification (PCO). Materials and methods:The study group consisted of 28 patients, average age 57 years (27 – 87 years), who underwent the cataract surgery of both eyes. Out of the 28 patients, the follow up examination after two or more years attended 23 of them. For the irrigation and aspiration after the phacoemulsification, the bimanual (newly also called biaxial) irrigation/aspiration from two service, 1 mm wide, opposite (at the 3 and 9 o’clock positions) incisions was used. In each patient, the lens capsule of one eye was mechanically polished in the maximal mydriasis (at least 5 minutes) with a specially constructed 5 openings aspiration cannula designated especially for the LEC aspiration in the equator area. The anterior capsule was cleaned by means of the standard one opening aspiration cannula. In the other eye of the same patient, the LEC of the anterior capsule were left intact. There was implanted the same type of the intraocular lens in both eyes. The examination after more than two years after the surgery consisted of biomicroscopic examination, taking the photograph of the intraocular lens and the lens capsule in retro illumination, and examining of the anterior segment by means of the Scheimpflug camera (Pentacam) with measuring the density of the anterior and posterior lens capsule. The Wilcoxon pair test was used for the statistical evaluation. Results: Using the Pentacam system objective densitometry, there was found statistically significant lower density of the anterior lens capsule in eyes with peroperative mechanical polishing of the lens capsule including the equator and the anterior capsule. Among the values of the density of the posterior capsule, there were found no statistically significant differences, although in 43 % of patients, in the eye with the polished capsule, there were visually less dense opacities of the posterior capsule. Conclusions: According to the obtained results it may be stated that the mechanical polishing of the lens capsule, including the equator and the anterior capsule, causes significantly lower degree of opacities of the anterior capsule (ACO), but has not statistically significant influence to the development of the PCO.

Článek

The Influence of Various Adhesive Systems and Polishing Methods on Enamel Surface Roughness after Debonding of Orthodontic Brackets: A Three-Dimensional In Vitro Evaluation

enamel surface is inevitable upon debonding of orthodontic brackets, adhesive removal, and finishing/polishing ...

Materials. 2023 ; 16 (14) : . [pub] 20230720

Materials (Basel)
ISSN 1996-1944
Medvik
Zdroj

A slight alteration of the enamel surface is inevitable upon debonding of orthodontic brackets, adhesive removal, and finishing/polishing. The aim of this in vitro study was to compare two adhesives and three polishing methods by measuring enamel surface roughness using confocal laser scanning microscopy (CLSM). Brackets were bonded on 42 extracted human premolars using Transbond XT (Transbond group) or Fuji Ortho (Fuji group). After debracketing, adhesives were removed with a tungsten carbide bur, and surfaces were polished using Sof-Lex discs, a rotary brush with a prophylactic paste (Depural), or a prophylactic cup with two polishing pastes (n = 7 in each subgroup). Surface roughness (Sa, Sku, Sq, and Sz) was measured using CLSM and compared before treatment (T1), after debracketing and adhesive removal (T2), and after polishing (T3). The data were statistically analyzed using the Mann-Whitney U and Kruskal-Wallis tests with Bonferroni correction. The time required for adhesive removal was measured and compared using a two-sample t-test. Surface roughness at T2 increased compared to T1, but the difference was significant only for the Fuji group (p < 0.01). The time required to remove Transbond XT (94.1 ± 6.8 s) was significantly higher compared to Fuji (72.1 ± 5.9 s, p < 0.0001). Polishing with Sof-Lex discs resulted in lower surface roughness compared to T1 (p = 0.018). Using Depural and polishing pastes showed no significant difference in surface roughness compared to T1, except for a significant decrease in Sa and Sq for Transbond (p = 0.043) and in Sku for Fuji (p = 0.018) after polishing with Depural. In conclusion, the removal of Transbond took significantly longer, but there were fewer residues of composite resin on the enamel surface. Sof-Lex discs decreased enamel roughness, whereas enamel morphology and roughness were similar to the pre-treatment state after polishing with polishing pastes.

Publikační typ
časopisecké články MeSH

Článek

1+1=3: Nový Air-Flow Master Piezon - sub- a a supragingiválny air polishing plus skejling - od jednotky v profylaxi

StomaTeam. 2013 ; 13 (2) : 55.

StomaTeam (Praha)
ISSN 1214-147X
Medvik
Zdroj

Publikační typ
inzerce MeSH

Článek

Influence of surface pre-treatment with mechanical polishing, chemical, electrochemical and ion sputter etching on the surface properties, corrosion resistance and MG-63 cell colonization of commercially pure titanium

Mechanical polishing, electrochemical etching, chemical etching in Kroll's reagent, and ion sputter etching ...

Materials science & engineering. C, Materials for biological applications. 2020 ; 115 (-) : 111065. [pub] 20200508

Mater Sci Eng C Mater Biol Appl
ISSN 1873-0191
Medvik
Zdroj

The impact of four pre-treatment techniques on the surface morphology and chemistry, residual stress, mechanical properties, corrosion resistance in a physiological saline solution and cell colonization of commercially pure titanium is examined in detail. Mechanical polishing, electrochemical etching, chemical etching in Kroll's reagent, and ion sputter etching with argon ions were applied. Surface morphologies reflect the nature of surface layer removal. Significant roughening of the surface and a characteristic microtopology become apparent as a result of the sensitivity of chemical and ion sputter etching to the grain orientation. The hardness in the near surface region was controlled by the amount of residual stress. Etching of the stressed surface layer led to a reduction in residual stress and surface hardness. A compact passivation layer composed of TiO, TiO2 and Ti2O3 native oxides imparted high corrosion resistance to the surface after mechanical polishing, chemical and electrochemical etching. The ion sputter etched surface showed substantially reduced corrosion resistance, where the corrosion process was controlled by electron transfer. The specific topology affected the adhesion of the cell to the surface rather than the cell area coverage. The cell area coverage increased with the corrosion stability of the surface.