|
Color stability of resin-based filling materials after aging when cured with plasma or halogen light.
Eur J Oral Sci. 2005 Jun;113(3):251-7.
Janda R, Roulet JF, Latta M, Steffin G, Ruttermann S.
The influence of curing devices and curing times on the color stability of filling
resins was investigated by measuring the CIE-Laboratory-values after performing dry storage,
water storage, and a Suntest (EN ISO 7491). Eight samples each of
Charisma (CH), Durafill (DU), Definite (DE), and Dyract AP (DY) were light cured by using
Translux Energy (TE) for 20, 40 or 60 s, or by using Apollo 95E (AP) for 3, 10 or 20 s.
Minor color changes occurred for all dry stored materials, devices and curing times.
The TE-cured, water-stored samples behaved similarly to the dry-stored ones, but the
samples cured with AP revealed very strong color changes, mainly because of a drastic
bleaching process. The bleaching of DU was significantly less than that of the other
materials, but a strong white shift occurred. CH, DE, and DU showed very little
(and even acceptable) discolorations after the Suntest when TE-cured. DY showed
a drastically discoloration. All samples cured using AP drastically bleached
and shifted to white for DU and DY but to dark for DE. In conclusion, the extent
of discoloration depends on (i) the material, (ii) the test method, (iii) curing time,
and (iv) the curing device.
The halogen light-cured samples performed best.
Sealing smooth enamel surfaces with a newly devised adhesive patch: a radiochemical in vitro analysis.
Dent Mater. 2005 Jun;21(6):545-50.
Schmidlin PR, Zehnder M, Zimmermann MA, Zimmermann J, Roos M, Roulet JF.
OBJECTIVES: To assess the enamel-protective potential of a newly devised adhesive patch when
used as a smooth surface sealant. METHODS: Eighty enamel discs were prepared from bovine
lower central incisors and then irradiated. Twenty specimens were treated with one of three
sealing options: enamel bond in a two-step application, the prototype of an adhesive patch,
or a flowable resin. Unsealed enamel served as positive controls. Loss of apatite was
determined using a radiochemical liquid scintillation method after immersion of the
samples in saliva or lactic acid (n=10 per treatment group) each for up to 21 days,
during which this experimental and control enamel surfaces were exposed to ten toothbrush
strokes per day. Quantitative liquid scintillation data were verified by polarized light
microscopy. RESULTS: With lactic acid exposure, a double layer of enamel bonding showed
better enamel protection than untreated controls, but was significantly less effective
than the adhesive patch or filled composite (P<0.05). No significant differences were
noted between the latter two treatments. SIGNIFICANCE: It was concluded that the
adhesive patch under investigation merits
further studies to assess its potential as an inter-proximal sealant.
Secondary caries-like lesions at fissure sealings with Xeno III and Delton--an in vitro study.
J Dent. 2005 May;33(5):443-9. Epub 2004 Dec 31.
Seemann R, Kluck I, Bizhang M, Roulet JF.
OBJECTIVES: The aim of the study was to establish a bacterial based in vitro caries model
to test the caries preventive effect of fissure sealants and to investigate whether a
self-etching adhesive (Xeno III) used as fissure sealant is equally effective in preventing
secondary caries compared to a conventional sealant (Delton) when applied on saliva
contaminated and non-contaminated fissures. METHODS: Forty caries-free upper premolars
were randomly divided into two groups. Group A was sealed with a conventional resin-based
fissure sealant (Delton) after phosphoric acid etching. Group B was sealed with a
self-etching adhesive (Xeno III) without prior etching. To simulate the clinical
situation of saliva contamination, the distal part of each tooth was slightly moistened
with saliva before sealant application. After thermo-cycling, the specimens were
exposed to a cariogenic Streptococcus mutans biofilm in an artificial mouth model.
Depths of demineralization were measured on serial sections by confocal laser scanning
microscopy. If a demineralization was detected underneath the whole fissure sealing the
sample was rated as 'total failure'. RESULTS: Significantly higher numbers of total
failures could be found in the Xeno III group compared to the Delton group in areas
without saliva contamination. On contaminated areas, no significant difference could
be found. There was no significant difference regarding the depth of the primary
carious lesions between groups. CONCLUSION: The study supports our recent findings
that our caries model is capable to produce secondary caries-like lesions at fissure
sealings. Based on the present in vitro data, it cannot be recommended to
use the self-etching adhesive Xeno III solely as a fissure sealant.
Clinically controlled study on the quality of class III, IV and V composite restorations after two years.
J Adhes Dent. 2004 Autumn;6(3):247-53.
Geitel B, Kwiatkowski R, Zimmer S, Barthel CR, Roulet JF, Jahn KR.
PURPOSE: The quality of fillings consisting of a hybrid composite was compared with fillings
consisting of two different microfilled composites in a clinical examination.
MATERIAL AND METHODS: Within the design of a clinically controlled two-year study
conducted under practice-relevant conditions, the composites C-Fill MH (Megadenta),
Helio Progress (Vivadent), and Visio-Dispers (ESPE) were examined in anterior-tooth
cavities in 134 patients by means of the split-mouth technique. The clinical examinations
were performed based on modified Ryge criteria (marginal integrity, anatomical form,
secondary caries, color, marginal discoloration, surface roughness) after 12 and 24
months. RESULTS: Immediately following filling application, all evaluation criteria
except color were assessed as level A. After 12 and 24 months, C-Fill MH was found to
be significantly superior to the other materials with regard to marginal integrity,
color, and marginal discoloration. CONCLUSION: The hybrid composite C-Fill MH seems
to be superior to the microfilled composites
and should therefore be preferred as a restorative filling material.
A multicenter clinical trial on the use of pulsed electromagnetic fields in the treatment of temporomandibular disorders.
J Prosthet Dent. 2004 Feb;91(2):180-7.
Peroz I, Chun YH, Karageorgi G, Schwerin C, Bernhardt O, Roulet JF, Freesmeyer WB, Meyer G, Lange KP.
STATEMENT OF THE PROBLEM: Pulsed electromagnetic fields have shown therapeutic benefit
in the treatment of numerous forms of osteoarthritis but have not been evaluated for
their effects on the temporomandibular joint (TMJ). PURPOSE: The aim of this study was
to examine the effects of pulsed electromagnetic fields in the treatment of patients with
temporomandibular disorders (TMD). MATERIALS AND METHODS: A multicenter clinical trial
compared active treatment of 36 patients using pulsed electromagnetic fields to placebo
treatment of 42 patients with TMD with pain in 1 or both TMJs and/or limited opening of
less than 40 mm. Subjective parameters including pain intensity, pain frequency, degree
of limitation, restriction of daily life, and intensity and frequency of joint noises
were evaluated using a visual analog scale. Trained, blinded examiners assessed the
clinical parameters according to Research Diagnostic Criteria for temporomandibular
disorders before treatment (baseline), directly after nine 1-hour treatments on
consecutive working days, 6 weeks after treatment, and 4 months after treatment.
Statistical evaluation was done using the Friedman test, and by paired comparison
between baseline and follow-up examinations using the U test (P < .05). RESULTS:
Seventy-six patients completed the study. For both the active and placebo treatment,
significant improvements were seen in the subjective data (P < .01). Patients with
anterior disk displacement without reduction also showed significant improvements in
active mouth opening (P = .015), patients with ostheoarthritis only showed improvements
in some of the subjective parameters (P < .03), and patients with anterior disk displacement
with reduction showed no improvement at all. CONCLUSIONS: Pulsed electromagnetic fields had no
specific treatment effects in patients with temporomandibular disorders
Can we fulfil even the basics of endodontic therapy?
Ann R Australas Coll Dent Surg. 2002 Oct;16:30-6.
Barthel CR, Roulet JF.
Micro-organisms and lipopolysaccharides (LPS) are involved in inducing periapical inflammation.
Therefore, it is important to eliminate them from the complex root canal system and seal the
endodontic space as accurately as possible. This is possible with a combination of the
following: instrumentation of the canal, eventually with new, motor driven instruments,
abundant rinsing with NaOCl, dressing preferably with Ca(OH)2, sealing the root canal and
incorporating the permanent
restoration within three months after root canal filling to avoid reinfection.
Intracoronal bleaching of discolored non-vital teeth.
Oper Dent. 2003 Jul-Aug;28(4):334-40.
Bizhang M, Heiden A, Blunck U, Zimmer S, Seemann R, Roulet JF.
This clinical study compared the effectiveness of bleaching non-vital teeth with an open
pulp chamber during bleaching using 10% carbamide peroxide compared to the modified walking
bleach technique and extracoronal bleaching. Sixty discolored, non-vital teeth were treated.
They were divided into three groups. Each group was treated with one of the bleaching
materials and methods: extracoronally using 10% carbamide peroxide for two weeks as
negative control (Group A), intracoronally using sodium perborate mixed with 3% hydrogen
peroxide (modified walking bleach technique) (Rotstein, Mor & Friedman, 1993) for four
weeks (Group B) and intracoronally and extracoronally using 10% carbamide peroxide for
two weeks (Group C) (Liebenberg, 1997). Tooth color was measured at baseline, (BL),
immediately post-bleaching (IP) and six months post-bleaching (SP) with a colorimeter
(Castor, Sigma, Germany) using a tooth-positioning jig. The color was determined
according to the CIELAB system, which records lightness as L* and chromaticity
coordinates as a* and b*. The difference in L* and b* among the three groups was
significant between BL and IP examination. The post-bleaching, whitening effect in
Group C was significantly better,
but after six months, in Group C, it was as effective as in Group B.
A new adhesive technology for all-ceramics.
Dent Mater. 2003 Sep;19(6):567-73.
Janda R, Roulet JF, Wulf M, Tiller HJ.
OBJECTIVES: Evaluation of a new surface treatment method to obtain a good bond strength
between a luting composite and several ceramics. METHODS: Specimen preparation and test
procedure were done according to ISO 10477 Amendment 1. The surfaces of Empress II,
InCeram-Alumina, InCeram-Zirconia and Frialit (ZrO2) were ground under water-cooling
with 400 grit grinding paper, afterwards polished with 800 grit and air-dried. Each
ceramic material investigated was divided into three groups of 10 specimens each.
Group 1 was flame-treated with the PyrosilPen for 2.5 s, group 2 for 5 s and group
3 for 10 s/cm(2). After the flame treatment, a methacryl silane was applied followed
by a luting composite. Prior to measuring shear bond strength, the specimens were
thermocycled 5,000 times in a water-bath between +5 and +55 degrees C. Furthermore,
SEM- and Fourier-transform infrared spectrophotometer (FT-IR)-investigations were done.
As a control, Empress II etched and silaned was used. RESULTS: Shear bond strength
measurements indicated that the optimal treatment time was 5 s/cm(2). Regarding this
time the following bond strength values between the luting composite and the various
ceramics were obtained: Empress II 23 (5)MPa, InCeram-Alumina 23 (5)MPa, InCeram-Zirconia
13 (8)MPa, and Frialit 16 (6)MPa. The control achieved 27 (6)MPa. On all surfaces of the
flamed specimens Si could be detected by FT-IR.Significance. The PyrosilPen-Technology is
an easy and effective method for surface-treating silicate, aluminum oxide and zirconium
oxide ceramics to obtain good bonding to luting composites.
Resin/Resin bonding: a new adhesive technology.
J Adhes Dent. 2002 Winter;4(4):299-308.
Janda R, Roulet JF, Wulf M, Tiller HJ.
PURPOSE: Evaluation of a new surface treatment method to obtain a good bond strength between
a luting composite and (1) a light-cured, (2) a heat-cured and (3) a thermoplastic resin.
MATERIALS AND METHODS: Specimens were prepared and tests conducted according to ISO 10477,
Amend. 1. The surfaces of Targis (light cured), SR Isosit (heat cured), and Dental D
(thermoplastic) were ground under water cooling with 400-grit grinding paper, polished
with 800-grit paper and air dried. Each resin material was divided into 3 groups of 10
specimens each. Group 1 was flame treated with a PyrosilPen for 5 s/2 cm2, group 2 for
10 s/2 cm2, and group 3 for 20 s/2 cm2. Subsequently, a methacryl silane was applied,
followed by a luting composite. Prior to measuring shear bond strength, the specimens
were thermocycled 5000 times in a water bath between 5 degrees C and 55 degrees C.
SEM, FTIR investigations, and fracture analysis were also done. Etched and silanized
Empress II - the gold standard - was used as a control. RESULTS: The following shear
bond strengths were found: treatment time 5 s/2 cm2, Targis 25 (+/- 12) MPa, SR
Isosit 17 (+/- 11) MPa; treatment time 10 s/2 cm2, Targis 23 (+/- 12) MPa, SR Isosit
26 (+/- 8) MPa; treatment time 20 s/2 cm2, Targis 29 (+/- 5) MPa, SR Isosit 26 (+/- 9)
MPa. All Dental D specimens failed completely so that shear bond strength could not
be measured. The control achieved 27 (+/- 6) MPa. No significant differences were
found between the materials or the flaming times. On all flamed surfaces, Si was
detected by FTIR. SEM showed that no heat destruction occurred at a flaming time
of 5 s/2 cm2, a slight change at 10 s/2 cm2, and a significant change at 20 s/2 cm2.
CONCLUSION: This new bonding technology is an effective method for surface-treating
polymerized composite resin materials to
obtain good bonding to luting composites. The method fails on thermoplastic resins.
|
|
|
