PubMed Health⌕ Search

PubMed · 15892359

Self-curing, self-etching adhesive cement systems.

Abstract

PURPOSE: To investigate the influence of the acid-base reaction between acidic monomers and amines on the polymerization behavior of self-etching, self-curing adhesives, determine the effect of the application mode on the shear bond strength and morphology, and elucidate the adhesion performance of such systems by shear bond strength measurements. MATERIALS AND METHODS: The amine redox-initiator system N,N-di(2-hydroxyethyl)p-toluene (DEPT)/dibenzoyl peroxide (BPO) was selected to investigate the influence of the amine-base reaction on polymerization behavior. The PKa value of DEPT hydrochloride was measured by titration with NaOH. The influence of the pH value and DEPT concentration on the polymerization rate of methacrylates was investigated by exotherm time measurements. Three different application protocols of Multilink Primer (Ivoclar Vivadent) and Panavia 21 ED-Primer (Kuraray) were tested, 15 s passive vs 15 s agitation vs 60 s passive in combination with the corresponding resin luting material. The effects of these three application protocols were evaluated and monitored by both shear bond strength tests and SEM characterization of the surface morphology. The adhesion potential of these self-etching, self-curing luting systems was compared on enamel and dentin both directly after application and after 24 h. RESULTS: The pKa of DEPT-HCl is 4.45. The polymerization rate of the DEPT-containing, self-etching, self-curing adhesive system is highly influenced by both the amine concentration and the pH value. In the case of Multilink, agitation of the primer mixture for 15 s, especially on dentin, resulted in a higher bond strength and a more pronounced removal of the smear layer. Multilink resulted in statistically higher bond strengths (p < 0.05) than Panavia 21 for both the enamel and dentin directly after application and for the dentin after 24 h. CONCLUSION: Radical polymerization initiators used in self-curing systems are strongly adversely affected by acidic monomers incorporated in self-etching adhesives. However, if there is a good adjustment of these components and effects of adhesive application are taken in account, high bond strengths can be achieved.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ulrich Salz, Jörg Zimmermann, Tobias Salzer. 2005. Self-curing, self-etching adhesive cement systems.. https://pubmed.ncbi.nlm.nih.gov/15892359/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Removal torque and physico-chemical characteristics of dental implants etched with hydrofluoric and nitric acid. An experimental study in Beagle dogs.

OBJECTIVE: To study the composition, surface characteristics and response to removal torque of an implant surface subjected to hydrofluoric acid etching and posterior passivating with hydrofluoric and nitric acid. STUDY DESIGN: Twelve implants were initially selected and their physico-chemical characteristics were evaluated by means of energy-dispersive X-rays (EDS), scanning electron microscopy (SEM) and photoelectron spectroscopy (XPS). In addition, 24 implants - 12 measuring 8 mm and 12 measuring 10 mm in length - were implanted in 6 Beagle dogs. Twelve implants were removed after a recovery period of 6 weeks, followed by removal of the remaining 12 implants after 12 weeks, using a torque calibrator (Gauge Tonichi model BGT150CN-S) with a force registry range of 0-150 Ncm. RESULTS: EDS analysis of the surface chemical composition only revealed the presence of titanium in the etched surfaces. In the same way as with the surfaces of other dental implants, XPS analysis revealed traces of other elements present in the surface, fundamentally carbon. Following dual acid etching, the surface showed the roughness resulting from acid action, with a morphology that proved to be quite homogeneous. The roughness values obtained exceeded 1 mm. The mean removal torque values after 6 weeks were 79.7 Ncm for the 8 mm implants and 115 Ncm for the 10 mm implants. After 12 weeks, these values increased to 101.2 Ncm and 139.7 Ncm, respectively. CONCLUSIONS: Hydrofluoric and nitric acid etching affords optimum surface characteristics comparable to those of other surfaces. The recorded removal torque values raise the possibility of human clinical application for early or immediate loading procedures.

Acid Etching, Dental↗

The impact of hydrofluoric acid surface treatments on the performance of a porcelain laminate restorative material.

OBJECTIVES: Hydrofluoric (HF) acid etching increases the bond strength between composite resin and porcelain surfaces and has been advocated as a pre-cementation technique for ceramic restorations. The internal surface flaw distribution which is implicated in the premature failure of ceramic restorations is modified by the etching process and little agreement exists amongst researchers as to the appropriate etching regime. The purpose of the current study was to examine the impact of HF acid concentration and etching time on the performance of a low fusing feldspathic porcelain. METHODS: Sets of 30 Vitadur-Alpha dentin porcelain discs (15 mm diameter, 0.9 mm thickness) were etched with HF acid of three different concentrations (5, 10 and 20%) and for three different etching periods (45, 90 and 180s). Mean flexure strengths, standard deviations and the associated Weibull moduli (m) and characteristic stress (sigma(0)) were determined using bi-axial flexure (ball on ring). Contact profilometry was utilised to characterise the roughness of the etched porcelain surfaces. RESULTS: A univariate general linear analysis of means revealed a significant reduction in the mean strength values of the as-fired control compared with groups subjected to HF acid etching. Further significance (P<0.05) was discovered with the impact of acid concentration. Altering etching time also resulted in changes in the reliability of the fracture strength data. Contact profilometry demonstrated an increase in surface roughness following HF acid etching and an increase in roughness associated with increasing HF concentration. CONCLUSIONS: Etching of feldspathic porcelain is a dynamic process and the impact is dependent on substrate constitution, surface topography, acid concentration and etching time. A significant reduction of the flexural strength of a low fusing feldspathic porcelain has been demonstrated to result from etching and clear evidence exists that the nature of surface flaw modification is a function of etching time and HF acid concentration. Favourable combinations of HF acid concentration and etching time have been identified which enhance the reliability of the porcelain utilised although variability in clinical technique will result in the reduced reliability of porcelain laminate restorations in function.

Acid Etching, Dental↗

Conditioning effect on dentin, resin tags and hybrid layer of different acidity self-etch adhesives applied to thick and thin smear layer.

OBJECTIVES: to assess the conditioning effect (CE) of self-etch adhesives of different acidity applied to thick and thin smear layer (SL), the corresponding resin tags (RT) and hybrid layer (HL). METHODS: Twenty-seven molars had their occlusal dentin exposed and were sectioned into two halves. Each of them was ground with a 60 or 600-grit SiC paper, respectively for thick and thin SL production. Three self-etch adhesives: a mild (Clearfil SE Bond), an intermediary (Optibond Solo SE and Solo Plus) and a strong (Tyrian Self Priming Etchant+One Step Plus) and an etch-&-rinse system (Scotchbond Multi Purpose Plus) were used. For CE evaluation, the self-etch primers were applied and rinsed off with acetone and alcohol prior to SEM preparation. For RT and HL specimens self-etch adhesives were applied and restored with Z-250. For RT specimens, dentin was removed with HCl (6N) and NaClO (1%) baths. The HL specimens were fixed, dehydrated, dried with HMDS, embedded, polished and slightly demineralized (6N HCl) and deproteinized (1% NaClO). After gold sputtering they were observed by SEM. RESULTS: The thick smear layer was clearly not totally removed by the mild self-etch primer. RT varied in density and shape among the self-etch adhesives. Thicker HL was observed for the strong self-etch and etch-&-rinse adhesives. CONCLUSIONS: The etch-&-rinse adhesive presented the thickest HL and was the only adhesive to produce RT in high density and uniform distribution along the whole dentin surface, independently of the SL thickness.

Acid Etching, Dental↗