Sažetak | Cilj istraživanja bio je utvrditi učinak dvaju adhezijskih sustava i staklenoionomernog premaza na
količinu otpuštenih fluoridnih iona i promjenu pH tijekom razdoblja od 168 dana. Također, cilj je
bio utvrditi promjenu mase uzoraka tijekom navedenog razdoblja.
U istraživanju su rabljena četiri restaurativna materijala: giomer Beautifil II, alkasitni kompozitni
materijal Cention, konvencionalni kompozit Filtek Z250 i konvencionalni staklenoionomerni
cement Fuji IX Extra. Svjetlosno polimerizirani kompozitni uzorci premazani su G-aenial Bond i
Clearfil Universal Bond Quick adhezijskim sustavom. Uzorci staklenoionomernog cementa
premazani su GC Fuji Coat LC premazom. Uzorci bez premaza rabljeni su kao reference.
Vremenski intervali u kojima su izmjerene pH vrijednosti i količina fluoridnih iona bili su: 0 (1
sat), 1, 2, 7, 28, 84 i 168 dan. Kumulativne količine otpuštenih fluoridnih iona nakon 168 dana
povećale su se kod nepremazanih uzoraka sljedećim redoslijedom: Filtek Z250 < Beautifil II <
Cention < Fuji IX Extra. Kompoziti premazani Clearfil Universal Bond Quick adhezijskim
sustavom otpuštali su manju količinu fluoridnih iona od nepremazanih uzoraka, a kumulativne
vrijednosti dosegnute nakon 168 dana povećavale su se sljedećim redoslijedom: Filtek Z250 <
Beautifil II < Cention. Kompoziti premazani adhezijskim sustavom G-aenial Bond, također su
otpuštali manje količine fluoridnih iona u usporedbi s nepremazanim uzorcima; s kumulativnim
vrijednostima koje su se povećavale kako slijedi: Filtek Z250 < Beautifil II < Cention. Kompoziti
premazani adhezijskim sustavom G-aenial Bond u svim su skupinama pokazivali pH vrijednosti u
kiselom rasponu (4, 4 – 5, 7) u vremenskim intervalima 1 sat i 24 sata. Vrijednosti promjene mase
uzoraka nisu bile statistički značajne. Količina otpuštenih fluoridnih iona varirala je među
ispitivanim restaurativnim materijalima i ovisila je o uporabi adhezijskog sustava i premaza.
Vrijednosti pH varirale su među materijalima, tretmanima i vremenskim intervalima. |
Sažetak (engleski) | Objective: The aim of this study was to determine the effect of two adhesive systems and a glass
ionomer coating resin on the amount of released fluoride ions from different restorative materials
over a period of 168 days. Additionally, pH changes in the immersion medium were monitored.
Null hypotheses were made that there is no statistically significant difference between the tested
dental materials in the amount of released fluoride ions, mass changes, and changes in pH of
immersed medium and that there is no difference between released fluoride ions in materials
prepared with or without dentin adhesive systems/coatings. Regarding the time factor, the null
hypothesis was set that there were no statistically significant differences in the stated parameters
between individual time points.
Material and methods: Four different restorative materials were investigated: a giomer Beautifil
II (Shofu Dental GmbH, Ratingen, Germany), an “alkasite” material Cention (Ivoclar Vivadent,
Schaan, Liechtenstein), a conventional composite Filtek Z250 (3M Deutschland GmbH, Neuss,
Germany), used as a negative control, and a conventional glass ionomer cement Fuji IX Extra (GC,
Tokyo, Japan), used as a positive control.
Light-cured composite specimens were coated using two adhesive systems: a universal adhesive
G-aenial Bond (GC Europe, Leuven, Belgium) and a universal fluoride-releasing adhesive Clearfil
Universal Bond Quick (Kuraray Europe, Hattersheim am Main, Germany). The glass ionomer
cement specimens were coated using GC Fuji Coat LC (GC Europe, Leuven, Belgium). Uncoated
specimens were used as references.
Specimens of the composite materials were prepared using cylindrical Teflon molds of 6 mm in
diameter and 2 mm in height. The molds were placed on a polyethylene terephthalate (PET) foil,
filled with uncured material and covered with another layer of PET foil (15). The excess material
was removed, and specimens were polymerized using an LED curing unit (Bluephase G2, Ivoclar
Vivadent, Schaan, Liechtenstein) with a nominal intensity of 1200 mW/cm2
for 20 s on each side.
Specimens of the GIC were cast into the mold described above, covered with PET films, and left
Katarina Kelić, disertacija_________________________________________________________________
to set for 6 min, as per manufacturer’s instructions (16). To ensure that the specimens were
surrounded by an aqueous medium, a plastic thread incorporated within each specimen was used
to hang the specimens from the cap of the vial. A plastic thread was weighed before incorporation
in order to calculate exact sample mass. Samples were weighed at every time interval using
analytical balance ABS-N/ABJ-NM (KERN, Balingen, Germany). Each sample was immersed
separately into a plastic vial containing 5 ml of deionized water at 37 °C and evaluated after 0, 1,
2, 7, 28, 84, and 168 days. At each time interval, the specimens were removed from the aqueous
medium, placed in 5 ml of new deionized water and stored in the incubator until the next time
point. The pH of the medium, in which the specimens were stored, was first measured using the
pH meter MP 220 (Mettler Toledo, Columbus, Ohio) and the InLab Expert Pro pH electrode
(Mettler Toledo, Columbus, Ohio). Prior to the pH measurement, the electrode was calibrated using
standard buffer solutions at pH = 4 and pH = 7.
A volume of 4.5 ml of the medium and 0.5 ml of TISAB III buffer (Total Ionic Strenght Adjustment
Buffer, Thermo Fisher Scientific, Chelmsford, USA) were placed in a new beaker to determine the
concentration of fluoride ions. Quantitative fluoride ions release was measured using a standard
ion-selective electrode Orion 9609BNWP (Thermo Fisher Scientific, Massachusetts, USA), ISO
19448: 2018. Before measurements, the ion-selective electrode was calibrated using a series of
standards of known concentration in a range of 10−5
–10−2 mol/L F−
.
Results: The cumulative amounts of fluoride ions released after 168 days increased for the
uncoated specimens of the restorative materials in the following order: Filtek Z250 < Beautifil II
< Cention < Fuji IX Extra. When comparing cumulative values after 168 days, FUJ demonstrated
3 times higher values than CN, and 35 times higher values than BF. FIL released fluoride ions only
when fluoride-releasing adhesive CB was applied. The composite specimens coated with Clearfil
Universal Bond Quick released a lower amount of fluoride ions than the uncoated specimens, with
cumulative values reached after 168 days increasing in the following order: Filtek Z250 < Beautifil
II < Cention. The composite specimens coated with G-aenial Bond also released lower amounts of
fluoride ions compared to the uncoated specimens; with cumulative values increasing in the
following order: Filtek Z250 < Beautifil II < Cention. pH values among dental materials differed
in the first measurement (1 h time point) in the following order: FIL < FUJ < CN < BF (6,16, 6,47,
6,83, and 7,26). Also, the values differed at the last measurement (168 days): FUJ < FIL < CN <
Katarina Kelić, disertacija_________________________________________________________________
BF (6,56, 6,63, 6,91, and 7,45). pH values showed growth tendency over time in all tested
materials. The composite specimens coated with G-aenial Bond in all groups showed pH values in
the acidic range (4,4- 5,7) at time intervals of 1 hour and 24 hours. There was no statistical
significance in mass changes in all tested materials.
Conclusion: The amount of released fluoride ions varied among dental materials and depended on
the use of adhesive systems and coatings. The glass ionomer Fuji IX Extra showed the highest
values of released fluoride ions followed by the alkasite material Cention and the giomer Beautifil
II. Both adhesive systems and the coat had a diminishing effect on released fluoride ions. pH values
of the immersion medium differed among materials, treatments, and time points. The amount of
released fluoride ions showed a growth tendency over time in all tested materials. pH values
showed growth tendency over time in all tested materials. The lowest pH values were identified in
all material specimens when coated with G-aenial Bond. Immersion in deionized water didn´t show
statistical significance in mass changes in all tested materials during all time points. |