Simonides Consani

Chemical etching solutions for creating micromechanical retention in resin-bonded retainers

This study introduced three chemical etching solutions capable of producing micromechanical retention in nickel-chromium and nickel-chromium-beryllium alloys used for resin-bonded retainers. The effectiveness of the chemical etching solutions was evaluated with tensile strength tests and photographs at various magnifications with a scanning electron microscope. Chemical etching with the CG-Etch solution produced suitable and uniform microretention whereas the other solutions were not effective on all metal alloys. Significant differences (p < 0.05) relating to tensile bond strengths were noted. The CG-Etch solution gave the highest mean bond strength compared with solutions II, III, and control groups.

Efeito do polimento químico sobre a rugosidade superficial de resinas acrílicas ativadas química e termicamente em diferentes períodos de armazenagem

The influence of chemical npolishing on the surface rough- nness of acrylic resin samples was nevaluated in this investigation. nThe samples, polished through nconventional and chemical me- nthods were submitted to surface nroughness test in Prazis Rug-3 nperfilometer. The data, submitted nto ANOVA and Turkeyx92s test at a n5% significance level, showed that nconventional polishing was more neffective when compared to chemi- ncal polishing in promoting a better nsuperficial smoothness. nKey words: chemical po- nlishing, surface roughness , acrylic nresins

Efeito da interação prensagem RS - esfriamento da mufla na movimentação dental em prótese total após armazenagem em agua

The purpose ofthis study was to investigate the dental movement in nmaxillary complete dentures after periods of storage in water. Twenty nmaxillary complete dentures were prepared with the anterior teeth nmounted in normal overlapping and the posterior teeth in Angles class I, nn relation to the teeth of the lower stone cast. The final pressing of the nflask was made with the RS tension system and the curing cycleprocessed nin hot water at 74°C for 9 hours. nThe deflasking ofthe denture was nmade after flask cooling in water nor in water plus bench storage for n3 hours. The distance measure- nments among I-I (incisive to nincisive),PM-PM(pre-molarto pre- nmolar), M-M(molar to molar), RI- nRM (right incisive to right molar) nand LI-LM (Ieft incisive to left nmolar) teeth were made with a nSTM Olympus linear comparator nmicroscope with precision of n0.0005 mm, after deflasking and nperiods ofstorage in water of7, 30, nand 90 days. The data were nsubmitted to ANOVA and Tukey s ntest at a significance level of 5%. nExcept for the LI-LM distance in nthe 30-day storage period, with the nflask cooling in water plus bench nstorage for 3 hours, there was no nstatistically significant difference nin the other distances, influenced nby the types of the denture cooling nwhen the flasks were pressed with naid of the RS tension system.

A importância da geometria do palato na adaptaçäo de próteses totais superiores

The authors analysed the ninfluence of the palate geometric nshapes (deep, intermediate and nflat) in the adaptation of thermic- ncured acrylic resin base in upper ncomplete dentures. The maladjust- nments between acrylic resin base nand stone cast were measured nfrom the cuts of the anterior, nmedium and posterior (post dam) nregions of the palate, with the aid nof a linear microscope. The results, nanalysed through the Tukey´s test n(p< 0,05), showed that the major nmaladjustments occurred in pos- nterior region of the palatal area, nnot being influenced by the palate ngeometric shapes. nKey words: complete denture; ndental materials; acrylic resin.