Indirect latex glove contamination and its inhibitory effect on vinyl polysiloxane polymerization

Effect of the manual manipulation of composite resin with latex gloves

Purpose: This in vitro study aimed to evaluate the influence of the manual manipulation of two composite resins: Filtek™ Z350XT (3M ESPE) and Herculite Précis® (Kerr), with latex gloves contaminated with powder, human saliva and alcohol, on the microhardness values. Material and Methods: Manual manipulation was evaluated using latex gloves with powder, latex gloves without powder, latex gloves without powder with saliva, latex gloves without powder with alcohol, and without hand manipulation or contaminants (control). Each resin was manually manipulated for 10 seconds and photoactivated for 20 seconds with a light intensity of 1000mW/cm2 using a VALO –Ultradent LED light– cured unit, and then each sample was evaluated on the microhardness Vickers tester Leitz (Wetzlar). The collected data were analyzed using Kruskal –Wallis and Mann – Whitney post-test (p<0.05). Results. Microhardness values showed a significant difference between the evaluated and control groups, showing lower microhardness values in the group of latex glove with powder for Filtek™ Z350XT and the group of latex glove without powder with saliva for Herculite Précis®. Conclusion. The manual manipulation of composite resins decreases their surface microhardness.

An Evaluation of the Effect of Various Gloves on Polymerization Inhibition of Elastomeric Impression Materials: An In vitro Study

Background:

Latex protective barriers such as gloves and rubber dam material have been used widely in restorative procedures for crown and bridge. However, the chemical used during latex glove fabrication is thought to inhibit the polymerization of elastomeric impression materials used for impression making which has a detrimental effect on the dimensional accuracy and surface definition of resultant casts used for restorative procedures. The objectives of the study were to examine the surface of different elastomeric impressions on contact with various gloves.

Materials and Methods:

This clinical study included a total of eighty specimens of two types of the putty elastomeric impression material were hand manipulated by wearing three different gloves materials and is placed on a marked area of a clean and alcohol-treated glass slab at room temperature. The specimens examined for any signs of polymerization inhibition. The specimen will be rated as being “inhibited” if any residue remains on the glass slab and absence of the above will result as “no inhibition.”

Results:

The results showed no interference with the polymerization inhibition of the selected elastomers followed by the nitrile glove. The latex gloves showed inhibited set of the elastomeric impression material but set after sometime confirming time-dependent inhibition of the impression material.

Conclusion:

This study shows that the use of latex and sometime nitrile gloves during crown and bridge procedures should be contraindicated and the use of vinyl gloves should be stressed when working with elastomeric impression materials.

The effect of various interim fixed prosthodontic materials on the polymerization of elastomeric impression materials

STATEMENT OF PROBLEM

After tooth preparation, interim fixed prosthodontic materials are used to fabricate interim restorations until the definitive restoration can be delivered. The polymerization of elastomeric impression materials may be inhibited when in indirect contact with interim fixed prosthodontic materials.

PURPOSE

The purpose of this study was to detect whether the polymerization of 6 commonly used types of elastomeric impression materials was affected by direct contact with 6 commonly used interim fixed prosthodontic materials and to further evaluate the efficacy of several decontamination methods to eliminate the indirect effect of the interim fixed prosthodontic materials on the setting of elastomeric impression materials.

MATERIAL AND METHODS

Six brands of elastomeric impression material (Virtual, Aquasil, Genie, Correct Plus, Express, Impregum) were evaluated in vitro after direct contact with various interim fixed prosthodontic materials (Trim Plus, Unifast, Integrity, Systemp C&B, Tuff-Temp, Protemp IV) by 3 general practitioners. The setting of the impression materials was visually scored as either inhibited or noninhibited. Latex was used as a positive control. The decontamination part of the study was done indirectly on the dentin of prepared natural teeth after they had been relined with the interim fixed prosthodontic material. The decontamination methods were air-water rinse, mouthwash (chlorhexidine 0.12%), 3% hydrogen peroxide, and pumice. A Kruskal-Wallis nonparametric analysis was used to evaluate the results.

RESULTS

Statistically significant setting inhibition was found with 5 brands of polyvinyl siloxane impression materials with all tested types of interim fixed prosthodontic material (P<.001) except Trim Plus. No tested interim fixed prosthodontic material caused inhibition with the polyether impression material, except for minimal inhibition with Protemp IV. The decontamination method performed with 3% H2O2 alone proved adequate in preventing impression material inhibition. Interexaminer reliability data were analyzed with the kappa correlation analysis. The examiners were in complete agreement (kappa +1).

CONCLUSION

Under these in vitro conditions, the direct contact of polyvinyl siloxane impression materials to some brands of interim fixed prosthodontic materials resulted in polymerization inhibition. Of the decontamination methods tested, only 3% H2O2 showed efficacy in preventing the inhibitory effect of the interim fixed prosthodontic material. For optimal results, definitive impressions should be made before the prepared tooth is exposed to an interim fixed prosthodontic material.

Comparison of the effect of different medicaments on surface reproduction of two commercially available Polyvinyl Siloxane impression materials - An Invitro Study

Objective:To determine the effect of different retraction cord medicaments on surface detail reproduction of polyvinyl siloxane impression materials and compare this effect on any two brands of commercially available polyvinyl siloxane impression materials. Material and methods: Four stainless steel dies were made according to ADA specification no.19. Three dies were treated with aluminium chloride (5%), ferric sulphate (13.3%) and epinephrine (0.1%) while the fourth one was left untreated to serve as control. Two impression materials (Dentsply and 3M ESPE) were used. Results: All the three medicaments adversely affected the surface detail reproduction of both the brands of the polyvinyl siloxane impression materials. These effects were statistically significant as compared to untreated control. The impressions of 3M ESPE brand have shown better surface detail reproduction as compared to Dentsply impression material. Conclusion: Surface detail reproduction of the polyvinyl siloxane impression materials is adversely affected by the retraction cord medicaments. The presence of moisture or any traces of the medicaments should be removed from the tooth surface to provide a dry field for the correct reproduction of the surface detail of these materials.

Key words:Polyvinyl Siloxane, retraction cord medicaments, surface detail reproduction.

Silicone impression materials and latex gloves. Is interaction fact or fallacy?

This review will explore the mechanism of delayed setting and inhibition of polyvinyl siloxane impression material by latex and examine the evidence for and against this phenomenon. Clinical implications are discussed and recommendations for clinical practice made.

CLINICAL RELEVANCE

The production of accurate polyvinyl siloxane impressions in the fabrication of indirect restorations/prostheses is vital for a good clinical outcome.

Effects of sulfur-based hemostatic agents and gingival retraction cords handled with latex gloves on the polymerization of polyvinyl siloxane impression materials

Objectives

This study investigated the possible interactions between three addition silicone materials (Express^®, Aquasil Ultra^® and Adsil^®), three hemostatic agents (ferric sulfate, StatGel FS^®; aluminum sulfate, GelCord^®; and aluminum chloride, Hemostop^®) and gingival retraction cords previously handled with latex gloves to determine whether direct contact with medicaments or indirect contamination by latex in conditions similar to those found in clinical practice inhibit or affect the setting of the impression materials.

Material and Methods

A portable device for the simultaneous test of several specimens was specifically developed for this study. Polymerization inhibition was analyzed by examination of the impressions and the molded surface. Ten trials were performed for each addition silicone material used in the study, at a total of 240 study samples.

Results

All the samples tested (N=240) were nonreactive regardless of the type of combination used.

Conclusions

Aluminum sulfate, ferric sulfate and aluminum chloride hemostatic solutions did not show any inhibitory potential on the addition silicone samples under study, and there were no changes in polymerization as a result of contact between addition silicone and retraction cords handled with latex gloves.