Class V Restorations Clinical Trial
Official title:
Shade Matching of Omnichroma (One Shade Universal Composite) Versus a Microhybrid Composite in Class V Restorations. A Randomized Clinical Trial
Background Resin composites are effective in restoring damaged teeth due to their good
esthetics, high surface gloss, and clinically acceptable wear resistance1. One of the most
challenging tasks a dentist has to confront in daily practice is matching the color of
composite restorations used in anterior teeth2.
Problem The shade selection is carried out subjectively with a visual shade guide and
generally under inadequate light conditions, which can lead to errors in color perception3.
The presence of discrepancies between the classic shade guides and the actual shade of
composite makes that task more difficult.4. Not only that, but there was also mismatch
between composite shades and the proprietary shade guides included with the composite kits 5.
A mock-up should be performed as a trial to assist in shade selection and ensure the
predictability of the esthetic result in restorative treatment6.
Rationale Shade matching has been a time consuming procedure. Recommendations were made to
make customized shade guides of the used composite material for more predictable results7.
Manufacturers have been aiming at providing materials with a blending effect; taking on the
color appearance from surrounding tooth structure 8. Introduction of Omnichroma by Tokuyama
is aiming at eliminating the shade taking procedure by providing a single shade universal
composite that is designed to blend with the surrounding tooth structure without the need for
a shade matching procedure.
Aim The aim of this study is to evaluate the shade matching ability of a new single shade
composite (Omnichroma; Tokuyama) compared to a conventional multiple shade microhybrid
composite in the restoration of class V restorations using USPHS criteria
Background and rationale:
Research question:
In class V restorations will there be a difference in shade matching between Omnichroma (one
shade) universal composite and a microhybrid (multiple shade) universal composite?
Statement of the problem:
The shade selection is carried out subjectively with a visual shade guide and generally under
inadequate light conditions, which can lead to errors in color perception. The presence of
discrepancies between the classic shade guides and the actual shade of composite makes that
task more difficult. Not only that, but there was also mismatch between composite shades and
the proprietary shade guides included with the composite kits. A mock-up should be performed
as a trial to assist in shade selection and ensure the predictability of the esthetic result
in restorative treatment.
Rationale for conducting the research:
Shade matching has been a time-consuming procedure. Recommendations were made to make
customized shade guides of the used composite material for more predictable results.
Manufacturers have been aiming at providing materials with a blending effect; taking on the
color appearance from surrounding tooth structure. Introduction of Omnichroma by (Tokuyama
Dental, Tokyo, Japan) is aiming at eliminating the shade taking procedure by providing a
single shade universal composite that is designed to blend with the surrounding tooth
structure without the need for a shade matching procedure.
Review of literature:
In 2004, Nahri compared the clinical efficacy of Z250 (3M, Saint Paul, MN, USA) with Z100
(3M, Saint Paul, MN, USA) in class III and class V restorations. A total of 148 restorations
were placed by different dentists. The study used modified USPHS criteria to evaluate the
restorations at baseline and for one year. Color match, along with marginal adaptation,
discoloration, and anatomic form were evaluated using specified criteria. Baseline evaluation
was done after one week from restoration placement. At baseline, 70% of the Z250 restorations
were rated as Alpha regarding color-match compared to 62% of the Z100 restorations. It was
concluded that there was no significant difference between the two materials and that both
can be used in class V restorations.
A study by Sakrana compared between the clinical performance of Palfique Estelite,( Tokuyama
Corp., Tokyo, Japan) resin composite and Palfique Toughwell (Tokuyama Corp., Tokyo, Japan)
Resin Composite in anterior class V restorations. Both are minifilled composites with
Palfique Estelite indicated for anterior restorations and Palfique Toughwell indicated for
both anterior and posterior ones. Seventy eight class V cavities were restored using Palfique
Estellite and eighty two were restored with Palfique Toughwell. Both groups were examined
immediately after polishing (baseline), after 6 months, and after 1 year. Both showed 100%
color match of rating Alpha (USPHS criteria) at baseline. At 6 months, 100 % of Palfique
Estelite restorations were still rated as Alpha, while only 90% of the Palfique Toughwell
restorations were still rated as Alpha. It was shown that Palfique Toughwell had more color
change after one year. Only 70% were rated as Alpha regarding color match after one year.
However, the difference was not significant and both materials prove to be reliable in class
V restorations.
Another study by Paravina found color differences between same shades of 2 microhybrid
composite when placed in specimens of different surrounding color or different size. They
used specimens of 2 composite shades placed circumferentially. The outer ring was using the
darker composite and the inner was the lighter. Palfique Estellite (Tokuyama, Tokyo, Japan)
composite of shade C2 was used as the darker outer composite. Lighter shades (A2 and B2) of
Palfique Estellite and Esthet-X (Dentsply/Caulk, Milford, DE) were used in the inner part.
Multiple diameters (2,4,6) of the inner part were used. In addition to that, single composite
specimens were prepared from the same shades for comparison. It was found that the same
shades of composite appeared differently when placed in different diameters. Also, when there
was less color difference between inner and outer disks, more color match is achieved. This
led to a conclusion that composites can have a blending effect. This blending effect
increased with decreased restoration size, decreased color difference, and translucency of
the used composite.
Mourouzis compared the blending effect of three commercially available composites in vitro,
microhybrid GC Gradia Direct Anterior (GC Corporation, Tokyo, Japan), microfilled Clearfil
Majesty Esthetic (Kuraray Medical Inc., Tokyo, Japan), and nanofilled IPS Empress Direct
(Ivoclar Vivadent, Shaan, Liechtenstein). The study was conducted on extracted teeth. Shade
was taken for the teeth using a spectrophotometer. The teeth were sectioned vertically and
restored using the three composite materials of the designated shade. The restorations were
made using a prefabricated mold. The shade was taken afterwards and compared to that of
intact teeth. Results were that all composite restorations had color differences with intact
teeth. However, this difference was not visible by human eye and it was concluded that a
color difference of ΔΕ<3.3 was considered clinically acceptable It was stated that the
properties of the composite material have a drastic effect over esthetics. The Ivoclar group
demonstrated the most color difference among the 3 groups.
McLaren et al introduced a technique using calibrated photography and photoshop for shade
analysis. Digital photographs were taken in Raw format using polarizing filters and a gray
card. The cross-polarizing filter is used for eliminating glare. The gray card is used to
calibrate exposure in Adobe Camera Raw (which comes in adjunction with Adobe Photoshop to
compensate for exposure differences between different camera-models. The authors provided
recommended camera settings for standardization of images. L, A, and B values were calculated
using digital color meter in photoshop and compared to those of shade tabs for shade
selection. The authors claimed this technique to be effective, useful, and accurate in shade
analysis.
In 2019, Paravina et al compared between color adjusting potential of 5 commercially
available universal composites namely Omnichroma (Tokuyama Dental, Tokyo, Japan), Filtek
Supreme Ultra (3M, Saint Paul, MN), TPH Spectra (Dentsply Caulk, Milford, DE), Herculite
Ultra (Kerr Corporation, Orange, CA), and Tetric Evoceram (Ivoclar Vivadent, Amherst, NY) in
vitro. Single and dual specimens were prepared. Single specimens were composed of the
composite material alone and were compared to denture teeth. Dual specimens were composed of
the restorative material placed in cavities prepared in acrylic teeth of different shades.
Comparisons were made between denture teeth and single specimens and dual specimens.
Comparisons were made visually and instrumentally. There was large color difference between
single specimens and Denture teeth. However, dual specimens showed more color match. This was
most pronounced in Omnichroma. It was concluded that Omnichroma had the most color adjusting
potential. This means that it had a great color difference between single specimens and
denture teeth. It also had the greatest color match in dual specimens.
6b. Explanation for choice of comparators:
Micro-hybrid composite was chosen as a comparator because it's considered a universal
composite to be used in anterior and posterior restorations. It has high filler content along
with good surface polish and color stability. Also according to a recent study, micro-hybrid
composite showed excellent color match and color stability compared to nano-filled composite
in five-years follow-up.
Interventions:
Patients attending at the Conservative and Esthetic Dentistry Department Clinic will be
screened. Those who meet the study inclusion criteria will be recruited. They will be
informed with the study and an informed consent will be signed if they approve.
First Periodontal treatment will be made and oral hygiene instructions will be enforced.
Shade taking procedure will be done visually using customized composite shade tabs for more
accuracy. Shade will be confirmed using cross-polarized photography and image analysis using
a digital color meter (Adobe Photoshop).
Once the shade is confirmed, the operator will start rubber-dam isolation and cavity
preparation using a round bur. Remaining caries will be excavated by a sharp excavator. A 1mm
bevel will be prepared in enamel margins.
Selective enamel etching will be done and a universal adhesive will be applied to both enamel
and dentin. After solvent evaporation, the bonding agent will be cured for 20 seconds. The
operator will be blinded to the material to be used till the placement of the restoration to
avoid bias. According to the concealed envelope, the tooth will be assigned to one of both
treatment groups. Composite will be placed incrementally and light cured for 20 seconds using
3M Elipar DeepCure-S LED Curing Light (3M, Saint Paul, MN, USA)
Post curing will be done using Glycerin to decrease the oxygen inhibited layer. Finishing
will be done using yellow and white finishing stones Intensiv (Intensiv SA, Montagnola,
Switzerland). More finishing and polishing will be done using (Enhance and Pogo (Dentsply
Sirona). Rubber-dam will be removed and patients will be recalled for baseline evaluation
after one week to allow for rehydration.
The assessor will be blinded to both treatment groups. She will give the restorations a score
using Modified USPHS score. Calibrated photographs will be taken using cross polarizing
filters and a gray card for image analysis using Photoshop.
Recall appointments will be after 3 months and 6 months. Same evaluation will be made to
assess color stability.
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