Roughness Analysis on Composite Materials (Microfilled, Nanofilled and Silorane) After Different Finishing and Polishing Procedures

W2210742120 · 수집 2026-10-04 18:12:22

T13049 Surface Roughness and Optical Measurements

CoT 라벨링

라벨링 전

PDF 파일

자동 다운로드한 PDF PDF 보기

기본 정보

DOI 제목 발행년도 저널 URL 페이지 열기 PDF URL PDF 열기 발행기관 피인용수 라이선스

추가 정보 초록

The finishing and polishing of composite materials affect the restoration lifespan. The market shows a variety of finishing and polishing procedures and the choice among them is conditioned by different factors such as the resulting surface roughness. In the present study, 156 samples were realized with three composite materials, -microfilled, nanofilled and silorane-, and treated with different finishing and polishing procedures. Profilometric analyses were carried out on the samples’ surface, the measured roughness values were submitted to statistical analysis. A complete factorial plan was drawn up and two-way analysis of variance (ANOVA) was carried out to investigate whether the following factors affect the values of roughness: (i) material; (ii) polishing/finishing procedure. Tukey post-hoc test was also conducted to evaluate any statistically significant differences between the material/procedure combinations. The results show that the tested materials do not affect the resulting surface quality but roughness values depend on the finishing/polishing procedure adopted. The procedures that involve: (a) the finishing with medium Sof-Lex discs and (b) the finishing with two tungsten carbide multi-blade milling cutters Q series and UF series are those that allow the lowest values of roughness to be obtained.

본문

_Send Orders for Reprints to reprints@benthamscience.ae_

_The Open Dentistry Journal,_ 2015, _9,_ 357-367 357

Open Access
# Roughness Analysis on Composite Materials (Microfilled, Nanofilled and Silorane) After Different Finishing and Polishing Procedures

Francesco Pettini 1, Massimo Corsalini 1,*, Maria Grazia Savino 1, Gianluca Stefanachi 1,
Daniela Di Venere 1, Carmine Pappalettere 2, Giuseppe Monno 2 and Antonio Boccaccio 2,*

_1Dental School - University of Bari, Piazza Giulio Cesare 11 – 70125, Bari, Italy;_ _2Department of Mechanics, Mathe-_
_matics and Management, Politecnico di Bari, Viale Japigia 182, 70126 Bari, Italy_

Abstract: The finishing and polishing of composite materials affect the restoration lifespan. The market shows a variety
of finishing and polishing procedures and the choice among them is conditioned by different factors such as the resulting
surface roughness. In the present study, 156 samples were realized with three composite materials, -microfilled, nanofilled
and silorane-, and treated with different finishing and polishing procedures. Profilometric analyses were carried out on the
samples’ surface, the measured roughness values were submitted to statistical analysis. A complete factorial plan was
drawn up and two-way analysis of variance (ANOVA) was carried out to investigate whether the following factors affect
the values of roughness: (i) material; (ii) polishing/finishing procedure. Tukey post-hoc test was also conducted to evaluate any statistically significant differences between the material/procedure combinations. The results show that the tested
materials do not affect the resulting surface quality but roughness values depend on the finishing/polishing procedure
adopted. The procedures that involve: (a) the finishing with medium Sof-Lex discs and (b) the finishing with two tungsten
carbide multi-blade milling cutters Q series and UF series are those that allow the lowest values of roughness to be obtained.

Keywords: Composite, finishing, polishing, profilometer, surface roughness.

INTRODUCTION

The improvement of the superficial properties of biomaterials has steadily grown in importance in modern industry.
Chemical-physical treatments of surface can be utilized to
control the events occurring in the interface between materials and the complex environment of biological phases [1]. In
particular, in the field of restorative materials, the finishing
and polishing phases are compulsory steps in conservative
dentistry not only in terms of beauty of the restoration but
also in terms of oral health keeping [2, 3]. In the last years,
following to the development of nanotechnology, restorative
materials have seen a fast and constant evolution in the quantitative and qualitative composition of the filler, the resin
mold and in the physical-chemical properties of the composite [4, 5]. The high performances exhibited by composite
materials, like microfilled, nanofilled and siloranes, has led
to their intensive utilization in Dentistry. The low roughness
of the restoration surface represents an essential requirement
for the periodontal integrity of teeth, for the marginal integrity of the restoration as well as for its longevity [6-8].

The failure or the absence of appropriate finishing and
polishing procedures leads to high values of roughness and
hence to unfavorable outcomes such as:

*Address correspondence to these authors at the Università degli Studi di
Bari (Italy) - Dental School, Piazza Giulio Cesare, 10, I-70121 Bari, Italy;
Tel: +39 0805478153; Fax: +39 0805478743;
E-mail: massimo.corsalini@uniba.it (Massimo Corsalini)

Politecnico di Bari, Dipartimento di Meccanica, Matematica e Management
(DMMM), Viale Japigia 182, I-70126 Bari, Italy; Tel: +39 0805962829;
Fax: +39 0805962777; E-mail: a.boccaccio@poliba.it (Antonio Boccaccio)

- dental plaque accumulation;

- less endurance to wear;

- gum irritation;

- poor esthetic quality;

- color alteration.

Relationships between polishing/finishing protocols,
thermal treatments and surface roughness were investigated
in the literature [9-11]. It appears that the roughness of restoration surface is mainly affected by polishing and/or finishing technique and operator’s manual skills. Standardized
methods of polishing a surface independently from individual operator’s skills have been proposed [12, 13].

The aim of the present study is to assess how the roughness of a restoration surface changes for different finishing
and polishing procedures and for different materials it is
made from.

MATERIALS AND METHODS

Materials and Finishing/Polishing Procedures Tested in
the Study

The roughness parameters have been investigated for the
following materials:

- _ESTHETX HD_ : Photopolymerizable micro-hybrid composite, radiopaque, utilized in the restoration of the anterior and posterior zones.

- _CERAMX MONO_ : Photopolymerizable nano-hybrid
composite, used in direct and indirect restorations of an

1874-2106/15 2015 Bentham Open

358 _The Open Dentistry Journal,_ 2015 _, Volume 9_ _Pettini et al._

terior and posterior zones, for splinting and tooth stub
restoration.

- _FILTEK SILORANE_ : Photopolymerizable silorane
composite, used in the restoration of the posterior zone.

A large variety of finishing and polishing tools are currently available on the market. Some of these have been investigated in the present study.

- _Tungsten Carbide Multi-blade Milling Cutters_ : These
devices are classified according to the number of blades
(from 8 to 30). The cutting tool includes an entry and exit
angle and to correctly work, must advance in the counterrotation sense;

- _Diamond Milling Cutters_ : These cutters are produced in
different shapes and dimensions and with different types
of grain (the dimensions of which range in the interval 8 50 μm). They are usually utilized in sequence; the cutter
with the higher granulometry (50 - 30 μm) is used to
rough-hew and mold the restoration. The final finishing
is then performed with a lower granulometry (8 - 15 μm)
cutter. The shape of the cutter changes according to the
part to finish; flame-shaped milling cutters are usually
utilized for vestibular zones, olive-shaped milling cutters
for the palatal ones.

- _Abrasive Wheels_ : These are flexible, decreasing granulometry wheels for finishing and polishing, with different
gauges and therefore, different rigidity. Each granulometry is associated with a different color. They can be used
singularly or in combination with diamond or multi-blade
milling cutters. The most common discs are made of a
paper frame sprinkled with abrasive (oxide alloy) of different grain. The discs have a small eyelet to be clickinserted to the spindle mounted on the hand-piece. The
finishing and polishing will be performed in three or four
operative steps. The wheels used in the present study
were Sof-lex (3M, St. Paul, MN, USA). The system includes wheels with four types of oxide alloy grain, from
rough to superfine.

- _Silicon Rubber Tips_ : These are flexible rubber tips composed of a silicon mold to which carbide silicon, oxide
alloy or diamond abrasive particles are added. These devices are strictly used for the final finishing and polishing; they are available on the market in different colors,
shapes and grain dimensions (15 - 40 μm). They are
mounted on the micromotor and used under large
amounts of water spray. In addition to the different grain
tips used in the multi-step procedure, the one-step silicone rubber tip was recently introduced on the market.
Once the finishing is terminated, the operator utilizes the
one-step silicone rubber to obtain a mirror polishing.

- _Polishing Pastes_ : These are diamond or oxide alloy
pastes with different grains. They have to be dry-applied
on the composite one or more times with discs, plastic
tips or goat-hair brushes.

The main features of the adopted procedures, the producer and batch number (of the items utilized in the experiments) are listed in Table 1 .

Preparation of Samples

For each tested material 52 samples were realized, using
thermoplastic resin molds. The molds were built by using the
following items/devices:

- _Nails_ : The nail head (with a diameter of 8 mm and a
thickness of 2 mm) was used as a model for the molds;

- _Extrastrong and Soft Chalk_ (Elite Dental Stones, Zhermack Spa, Badia Polesine (RO), Italy);

- _Thermoplastic Resin Discs_ with a 125.0 mm diameter
and a 3.0 mm thickness (Imprelon, Scheu Dental GmbH,
Iserlohn, Germany)

- _Infrared Heater_ : Biostar (Scheu Dental GmbH, Iserlohn, Germany).

Table 1. Schematic of the principal features of the polishing/finishing procedures adopted in the experiments.

Finishing Procedures Composition Producer Batch N.

Sof-lex middle-grain abrasive discs Oxide alloy 3M ESPE, St. Paul, MN, USA 127683

Tungsten carbide multi-blade milling cutters: 860168�

Tungsten carbide KOMET ITALIA, Milan, ITALY
Q series + UF series 871818

Diamond milling cutters�

Red ring 50 μm�
Yellow ring 30 μm

884220�
Diamond KOMET ITALIA, Milan, ITALY
852330

Polishing Procedures Composition Producer Batch N.

Sof-lex, fine and extrafine grain abrasive discs

Oxide alloy 3M ESPE, St. Paul, MN, USA 127683
(multi-step procedure)

Ultrafine diamond grain rubber tip with
Silicone rubber tip (one-step procedure) KOMET ITALIA, Milan, ITALY 867287

flexible silicone binder

Experience seal coat, Experience polish paste
(+ goat-hair brush and cotton mop (multi-step)

Experience seal coat: resine acrilate e metil
metacrilate Experience polish paste: oxide

alloy, water, glycerine and sweetener.

5105695�
DEI Italia, Mercallo, VA, ITALY
2011003569

_Roughness Analysis on Composite Materials_ _The Open Dentistry Journal,_ 2015 _, Volume 9_ 359

The following procedure was adopted.

1. With the impression chalk, a prism was realized in which
the nails were inserted (Fig. 1(a) );

2. Thermoplastic disks were heated with the Biostar system
at the temperature of 220° C for 90 seconds thus losing
their initial consistency (Fig. 1(b) );

3. The discs were inserted into the model at a pressure of
4.1 atm so as to reproduce the shape of the nail head (Fig.
1(c) );

4. After being shaped and once the cooling was completed,
the discs were finally removed (Fig. 1(d) );

5. The discs were finally cut with a milling cutter in many
different squares (Fig. 1(d-e) ) the surface of which was
then polished (Fig. 1(f) ).

The composite materials were hence put in the molds
with a putty knife and covered with a Mylar strip and a microscope slide (Fig. 2(a) ). The strip was utilized so as to
avoid the formation of an oxygen inhibition layer, whereas
through the slide a load of about 20 N was applied on the

Thermoplastic resin disk

composite surface thus enabling the consolidation and the
discharge of material’s excess.

The samples, together with the strip and the slide, were
radiated for 40 seconds (according to the Manufacturer’s
prescriptions), by a halogen lamp (Degulux soft-star,
Degussa-Hülls, Hanau, Germany) placed perpendicularly
with respect to the sample surface and working at an intensity greater than 600 mW/cm 2 (Fig. 2(b) ). After the polymerization was completed, the samples were kept for 24 hours
at the temperature of 37°C and 100 % of humidity so as to
complete the process and then dried.

Finishing and Polishing of the Samples

After examining the samples to check any possible inner
voids, the samples were finished and polished by adopting
the following procedures:

- _Procedure A_ : (control group): A control group including
4 samples was collected for each of the tested composite
materials. All the samples of the three control groups
were neither finished nor polished after polymerization.

(b)

Nails inserted into
the chalk

(a)

(e) (f)

Fig. (1). Principal phases during the preparation of the samples. ( a ) A prismatic model was first built with impression chalk within which
different nails were inserted. Thermoplastc resin disks were heated with the Biostar System ( b ) and inserted into the model at a pressure of
4.1 atm so as to reproduce the dimension of the nail head ( c ). After being shaped and once the cooling was completed, the discs were removed ( d ). The discs were finally cut with a milling cutter in many different squares ( d-e ) the surface of which was then polished ( f ).

360 _The Open Dentistry Journal,_ 2015 _, Volume 9_ _Pettini et al._

- Superficial degreasing with 95° alcohol;

- Application of Experience seal coat (DEI Italia S.r.l.,
Mercallo (VA), Italy) on the surface with circular
movements with a microbrush gently rubbing it until
the solvent evaporated;

- Removal, after 3 minutes, of the surplus with a new
microbrush and photopolymerization for 90 seconds
with a halogen lamp (Degulux soft-star).

(a)

(b)

Fig. (2). ( a ) The composite materials were put in the molds with a
putty knife and covered with a Mylar strip and a microscope slide.
( b ) The samples, together with the strip and the slide, were radiated
for 40 seconds by a halogen lamp.

- _Procedure B_ : 16 samples for each composite were
treated with this procedure. The finishing procedure was
carried out for thirty seconds with medium Sof-Lex (3M,
St. Paul, MN, USA) discs. The discs, according to the
Producer’s guidelines, were mounted on the micromotor
together with the spindle. The discs were then used with
uniform and regular movements from the restoration towards the margin (and not vice-versa) avoiding forwardbackward movements on the composite/mold margin
which could have resulted in the formation of a white
line and hence of a discontinuous region. The whole
procedure was operated in the absence of water. At the
end of the finishing process, the samples were washed
and dried with an airflow. Twelve samples (four for each
composite) were not polished (Group B1). The remaining
samples (Group B2) were polished as follows:

- 12 samples (4 for each composite) were polished for 30

seconds with fine and superfine Sof-lex discs always inserted to the spindle and mounted on the hand-piece
(Group B2I).

- 12 samples (4 for each composite) were polished for 30

seconds with a silicone rubber tip. The rubber tip was
used with slightly circular movements at a speed of 6000
rpm, under an adequate refrigeration obtained with a 50
ml/min water flow. A special care was taken in minimizing the pressure exerted with the disc on the polished surface (Group B2II);

- 12 samples (4 for each composite) were polished with the

following procedure:

- Dry-application of Experience polish paste (DEI Italia
S.r.l.) with soft goat-hair wheel until the complete
removal of any residual seal coat fast;

- Dry-polishing with cotton mop and Experience Polish
Paste (Group B2III).

- _Procedure C_ : 16 samples for each composite were
treated with this procedure. The samples were finished
with two flame-shaped diamond milling cutters: firstly, a
50 μm (red ring) rough-grain, then a 30 μm (yellow ring)
extrafine grain milling cutter was utilized. Each milling
cutter operated for thirty seconds. The cutters were
mounted on the turbine and used under abundant irrigation. After the finishing, the samples were washed and
dried with an airflow. Twelve samples (four for each
composite) were not polished (Group C1). The remaining
samples (Group C2) were classified and polished according to the scheme utilized for Procedure B and summarized in Table 2 . For instance, Group C2I includes 12
samples (4 for each composite) polished for 30 seconds
with fine and extrafine-grain Sof-lex discs inserted into
the spindle and mounted on the hand-piece. Analogously,
Group C2II includes 12 samples polished for 30 seconds
with a silicone rubber tip, while Group C2III includes 12
samples submitted to the same treatment as that utilized
for samples of Group B2III (Table 2 ).

- _Procedure D_ : 16 samples for each composite were
treated with this procedure. The samples were finished
with two tungsten carbide multi-blade milling cutters Q
series (yellow-blue) and UF series (white) for 30 seconds
for each milling cutter. They were mounted on the turbine and used under plentiful irrigation. After the finishing was completed, the samples were washed and dried
with airflow. Twelve samples (four samples for each
composite) were not polished (Group D1). The remaining
samples (Group D2) were polished according to the
scheme shown in Table 2 .

In order to reduce the variability of the preparation procedures, finishing and polishing were performed by the same
operator. At the end of these phases the samples were
washed with distilled water and left drying for 24 hours before the roughness analysis.

Roughness Analysis

Any surface, even if worked with great accuracy, when
observed with a microscope will reveal roughness due to
grooves and crests determining local distancing, more or less
extended, of the real surface from the one conceived in the
design. Roughness (or absolute roughness) is a property of
the object surface, it consists of geometric microimperfections either originally included in the material of

_Roughness Analysis on Composite Materials_ _The Open Dentistry Journal,_ 2015 _, Volume 9_ 361

Table 2. Groups tested in the study.

Polishing
with silicone

rubber tip

Application of Experience seal coat,
Experience polish paste (+ goat-hair

brush and cotton mop (multi-step))

No
Polishing

Polishing with fine

and superfine

Sof-lex discs

Procedure B
B1 B2I B2II B2III
Samples finished with medium Sof-Lex discs

Procedure C
Samples finished with two flame-shaped diamond

milling cutters

Procedure D
Samples finished with two tungsten carbide multi
blade milling cutters Q series and UF series.

Procedure A
Samples neither finished nor polished after po
lymerization

C1 C2I C2II C2III

D1 D2I D2II D2III

Control Group

which the surface is made or due to the manufacturing process. These imperfections usually take the form of grooves or
scratches varying in shape, depth and direction. In order to
assess the roughness of a surface, a profilometer is used. The
measuring procedure is performed in the recording of the
profile of the surface along a specific measuring path (or
scanning path). This profile is then analyzed defining a numerical parameter which is the roughness value. A crucial
phase of the roughness measurement process is the filtering
procedure which allows the assessment of the sole quality of
the surface to be separated from the effects that the geometrical errors have on the measured profile. In the present
study, after the finishing and polishing were performed, the
superficial roughness of the samples was measured with the
profilometer Mahr MarSurfGD25 (Mahr Inc., Gottingen,
Germany) (Fig. 3 ). The measuring conditions, according to
ISO (International Standards Organization) 4287 Standard
were:

- Value of the profilometric resolution: 0.01 μm

- Transverse length (TL): 5.6 mm (n=5)

- Sample length (SL): 2.5 μm

- Vertical band width: ±250 μm

- Scanning Rate Vt: 0.50 mm/s

- Number of acquired points: 11200

The assessed parameter was Ra, i.e. the average arithmetic roughness. It is the most common parameter and represents the average absolute value of the deviations of the detected surface from the “average value” of the profile (technical surface) (ISO 4287). Also in this case, all the roughness
measurements were carried out by the same operator.

Statistical Analysis

The statistical analysis was aimed at identifying, by twoway analysis of variance (ANOVA), the factors that affect
the quality of the restoration surface. A complete factorial
plan was drawn up (Fig. 4 ), assessing two factors: (i) material; (ii) procedure. The null hypothesis _Ho_ was that factors
(i) and (ii) do not affect the roughness values. _Ho_ was as

sumed to hold true for _p-values_ - 0.05 (95 % confidence
interval). For factor (i) three levels were fixed: ESTHETX
HD, CERAMX MONO and FILTEK SILORANE; for factor
(ii) four levels: procedure A, B, C and D. A total of 156
roughness values were submitted to statistical analysis: 12
values for Procedure A [4 (replications) � 3 (number of
tested composite materials)]; 48 values for Procedure B [4
(replications) � 4 (number of sub-groups, i.e. B1, B2I, B2II,
B2III) � 3 (number of tested composite materials)]; 48 values for Procedure C [4 (replications) � 4 (number of subgroups, i.e. C1, C2I, C2II, C2III) � 3 (number of tested composite materials)]; 48 values for Procedure D [4 (replications) � 4 (number of sub-groups, i.e. D1, D2I, D2II, D2III)

- 3 (number of tested composite materials)].

Profilometer probe

Tested sample

Fig. (3). The profilometer Mahr MarSurfGD25 while measuring the
roughness of a sample. The profilometer probe comes in contact
with the surface detecting the profile of the scanned path.

362 _The Open Dentistry Journal,_ 2015 _, Volume 9_ _Pettini et al._

A non-parametric test (analysis of variance on ranks with
Tukey post-hoc test) was utilized to compare the roughness
values obtained with the different procedures and materials.

PROCEDURE

A (Control)

~~×~~ ~~×~~ ~~×~~

~~×~~

MATERIAL

ESTHETX HD CERAMX MONO

~~×~~

FILTEK SILORANE

Fig. (4). Complete factorial plan designed to identify the factors that
have a statistically significant influence on the roughness surface.

RESULTS

Two-way ANOVA revealed that the factor (ii) procedure,
p-value = 0.000 certainly does affect the roughness values
while roughness seems to be rather insensitive to the factor
(i) material, p-value = 0.109. For each of the investigated
material/procedure combinations, the median value, the first
quartile, third quartile, minimum and maximum values are
indicated in the boxplot of Fig. ( 5 ). In the Tables 3, 4, 5 and
6 we report the mean values with the standard deviation of
Ra evaluated in the procedures A, B, C and D, respectively,
for all the investigated materials. The mean roughness values
measured for different levels of factors (i) and (ii) are shown
in the main effects plot (Fig. 6 ). The highest values of Ra
were found for samples treated with procedure A, i.e. for
samples neither finished nor polished after polymerization.
Tukey post hoc test showed that there were statistically significant differences between the roughness measured on
samples treated with procedure A and that measured on
samples submitted to procedures B and D. No statistically
significant differences could be seen between the Ra values
of procedure A and those of procedure C (Table 7 ). However, averagely, the roughness values found for samples
submitted to procedure C are smaller than those measured in
the case of the procedure A (Fig. 6, Table 7 ). Furthermore,
no statistically significant differences have been found between the roughness values obtained for different materials.
The average values of roughness measured on samples submitted to polishing (in addition to finishing) are approximately 10-20 % smaller than those measured on samples
solely finished (Fig. 7 ).

DISCUSSION

In the present study, different composite materials were
submitted to polishing and finishing procedures. Roughness
measurements were carried out by means of a profilometer
and the resulting roughness values were submitted to statistical analysis. A two-way ANOVA was utilized to analyze
whether the surface roughness depends on the material it is
made from and the procedure with which it has been treated.

(a)

(b)

(c)

(d)

Fig. (5). Boxplot of roughness values determined for the different
groups of tested samples: ( a ) procedure A; ( b ) procedure B; ( c )
procedure C; ( d ) procedure D.

In order to understand the values measured in the study it
must be taken into consideration the fact that the superficial
micromorphology obtained after finishing and polishing is
affected by some factors [14-16].

_Roughness Analysis on Composite Materials_ _The Open Dentistry Journal,_ 2015 _, Volume 9_ 363

Table 3. Average roughness Ra and standard deviation measured for procedure A (control group, samples neither finished nor

polished).

Procedure Ra [μm] Std dev [μm]

ESTHET X HD A 1.288 0.758

CERAM-X MONO A 1.389 0.153

FILTEK SILORANE A 1.081 0.622

Table 4. Average roughness Ra and standard deviation measured for procedure B (samples finished with middle grain abrasive

discs and successively polished).

Procedure Ra [μm] Std dev [μm]

ESTHET X HD B1 0.787 0.240

CERAM-X MONO B1 0.543 0.211

FILTEK SILORANE B1 0.558 0.1812

ESTHET X HD B2I 0.129 0.048

CERAM-X MONO B2I 0.272 0.199

FILTEK SILORANE B2I 1.183 0.802

ESTHET X HD B2II 0.3545 0.127

CERAM-X MONO B2II 0.528 0.099

FILTEK SILORANE B2II 0.126 0.078

ESTHET X HD B2III 0.328 0.125

CERAM-X MONO B2III 0.529 0.125

FILTEK SILORANE B2III 1.055 0.011

Table 5. Average roughness Ra and standard deviation measured for procedure C (samples finished with diamond milling cutters

and successively polished).

Procedure Ra [μm] Std dev [μm]

ESTHET X HD C1 1.556 0.130

CERAM-X MONO C1 1.444 0.096

FILTEK SILORANE C1 0.469 0.249

ESTHET X HD C2I 1.023 0.091

CERAM-X MONO C2I 0.764 0.139

FILTEK SILORANE C2I 0.257 0.029

ESTHET X HD C2II 1.318 0.198

CERAM-X MONO C2II 0.712 0.085

364 _The Open Dentistry Journal,_ 2015 _, Volume 9_ _Pettini et al._

(Table 5) continued

Procedure Ra [μm] Std dev [μm]

FILTEK SILORANE C2II 0.535 0.166

ESTHET X HD C2III 1.311 0.084

CERAM-X MONO C2III 1.218 0.176

FILTEK SILORANE C2III 0.853 0.585

Table 6. Average roughness Ra and standard deviation measured for procedure D (samples finished with tungsten carbide multi-

blade milling cutters and successively polished).

Procedure Ra [μm] Std dev [μm]

ESTHET X HD D1 0.868 0.071

CERAM-X MONO D1 0.751 0.105

FILTEK SILORANE D1 0.319 0.008

ESTHET X HD D2I 0.252 0.108

CERAM-X MONO D2I 0.212 0.085

FILTEK SILORANE D2I 1.022 0.644

ESTHET X HD D2II 0.485 0.103

CERAM-X MONO D2II 0.721 1.103

FILTEK SILORANE D2II 0.257 0.060

ESTHET X HD D2III 0.475 0.151

CERAM-X MONO D2III 0.455 0.109

FILTEK SILORANE D2III 0.342 0.021

(a) (b)

PROCEDURE

Fig. (6). Main effects plot reporting the values of roughness averaged over the factors (i) materials and (ii) procedure. The horizontal line
reported in the two diagrams represents the average roughness value measured in all the experiments conducted. For example, the value of
roughness reported in the diagram ( a ) for the material CERAMX MONO, represents the average roughness value measured on all the samples
made of this material. Similarly, the roughness value reported in the diagram ( b ) for the procedure B represents the value of roughness averaged over all the measurements carried out on samples treated with this procedure.

_Roughness Analysis on Composite Materials_ _The Open Dentistry Journal,_ 2015 _, Volume 9_ 365

Table 7. Average values (computed over the four procedures) and standard deviation of roughness Ra measured in the experimen-

tal tests. Statistical comparisons (Tukey post-hoc test, Control Group A) are shown in the last column.

A [ μ m] B [ μ m] C [ μ m] D [ μ m] Comparison vs A

mean 1.253 0.533 0.955 0.513

B, D
Std dev 0.535 0.401 0.449 0.316

(a)

(b)

(c)

Fig. (7). Boxplot of roughness values measured for the samples
treated with procedure B ( a ), C ( b ) and D ( c ) in the case of polishing included (B2, C2, D2) or excluded (B1, C1, D1). The boxplot
that refers to group B2 includes the roughness values obtained for
the sub-groups: B2I, B2II and B2III. Analogously, groups C2 and
D2 include the sub-groups C2I, C2II, C2III and D2I, D2II, D2III,
respectively.

- Polymerization-related factors: the main controversy related to the finishing and polishing of composites is about
the time to begin these procedures. Whereas some
authors claim that finishing and polishing have to be per

formed after the removal of the mold or in the following
five minutes, other authors advise for a 24 hour-delay as
not to damage the margin of the restoration. Furthermore,
according to these authors, immediate finishing and polishing could result in a flux in composites due to thermal
perturbations [17]. After polymerization, composites are
subjected to hygroscopic expansion which reduces microinfiltrations [18]. Performing the finishing and polishing at a later stage would nonetheless compromise the
marginal sealing obtained with the hygroscopic expansion of the composite and adhesive system, engendering
an increase in microinfiltrations. Instant procedures instead would compromise the initial marginal keeping,
still the hygroscopic expansion could contain the situation [19].

- Finishing and polishing procedures-related factors such
as: abrasive hardness, geometry, flexibility and application speed of the polishing/finishing tools [20-22]. Consistently with this, in the present study statistically significant differences were found between the values of Ra
obtained on samples submitted to different finishing/polishing tools and/or procedures.

- Operator-related factors: studies in literature are conflicting because according to some authors the operator’s age
and experience do not seem to affect the polishing quality
and consequently the superficial characteristics. For other
authors the operator’s experience and expertise can also
affect the final superficial roughness degree [12, 13].

The roughness analysis carried out in the present study
showed that the finishing and polishing procedures have certainly beneficial effects on the quality of the restoration surface. The average value of Ra measured for samples treated
with procedure A (control group) is about twice as large as
that measured for procedure B and D. The statistical analysis
showed no statistically significant differences between the
samples treated with procedure A and those treated with procedure C, however, the values of Ra measured for the first
samples were averagely 20 % higher than those measured for
the second ones (Fig. 6(b) ). ANOVA showed that the tested
materials do not affect the resulting surface quality but
roughness values depend on the finishing/polishing procedure adopted. It can be seen, in fact, that the average values
of Ra obtained for the three tested materials are practically
overlapping (Fig. 6(a) ) while change significantly for different finishing/polishing procedures (Fig. 6(b) ). The procedure
assuring the best results was procedure B and procedure D
(Fig. 5 and 6 ). In all the procedures tested in the study, the
polishing operation allows values of roughness averagely
smaller than those of samples solely finished, to be obtained
(Fig. 7 ).

366 _The Open Dentistry Journal,_ 2015 _, Volume 9_ _Pettini et al._

Ra [  m]

Fig. (8). Histograms showing, for each procedure investigated, the percentage of samples the roughness of which falls within given intervals.
For example, with reference to procedure A, about 8 % of samples presents a roughness within the interval 0.1 - 0.3 μm; similarly, with reference to procedure D, about 37 % of the samples present a roughness that falls within the interval 0.3 - 0.5 μm. The dashed red lines represent
threshold roughness values reported in the literature above which a simultaneous increase in the plaque and in the risk of caries and periodontal inflammation is associated.

Assessing these values is of great importance since a
missing finishing and polishing causes a series of negative
occurrences, among which the adhesion of bacterial plaque
to the composite [2] and the consequent onset of secondary
caries. Many studies show a strong correlation between the
material roughness and the initial adhesion of bacterial
plaque. The minimum roughness value still remains unclear.
Some authors claim it to be 0.7-1.44 μm, others 0.25-0.50
μm or 0.2 μm [23, 24]. Considering that any reduction in
bacterial accumulation is predicted under these thresholds,
any increase in the superficial roughness above these values
is associated with a simultaneous increase in the plaque and
in the risk of caries and periodontal inflammation [2]. Interestingly, a large number of samples with roughness exceeding 1.44 μm has been found only in the case procedure A
(Fig. 8 ). 50 % (note: this value can be easily determined by
summing up the percentages related to the histograms with
Ra > 1.44 μm) of samples treated with procedure A, in fact,
present Ra values greater than 1.44 μm (Fig. 8 ). The percentage of samples with Ra > 1.44 μm is about 32 %, 2 % and 1
%, in the case of procedures C, B and D, respectively. A
wide incidence of samples with Ra < 0.7 μm, can be found
only for procedures B and D (Fig. 8 ).

The proposed study presents some limitations. First of
all, all the polishing/finishing procedures were carried out by
the same expert operator. In spite of the care taken in carrying out all the operations according to the prescribed protocol, it is reasonable to hypothesize that the quality of the
work done may depend on “human” factors such as the level
of attention, wrist trembling, that cannot be controlled. Secondly, the roughness analysis was carried out by using a profilometer that detects the shape of the surface along specific
paths. The utilization of new technologies [25] based on op

tical methods would enable to measure the roughness not
only on paths but on entire areas thus allowing to significantly increase the number of sampled points.

CONCLUSION

1) Different composite materials were submitted to polishing and finishing procedures. Roughness measurements
were carried out by means of a profilometer and the resulting roughness values were submitted to statistical
analysis.

2) ANOVA showed that the tested materials do not affect
the resulting surface quality but roughness values depend
on the finishing/polishing procedure adopted.

3) The roughness analysis showed that the finishing and
polishing procedures have certainly beneficial effects on
the quality of the restoration surface. The average value
of Ra measured for samples neither finished nor polished
is about twice as large as that measured for procedure B
(finishing with medium Sof-Lex discs) and D (finishing
with two tungsten carbide multi-blade milling cutters Q
series and UF series) and 20 % higher than that obtained
with procedure C (finishing with two flame-shaped diamond milling cutters).

4) The procedures that involve: (i) the finishing with
medium Sof-Lex discs and (ii) the finishing with two
tungsten carbide multi-blade milling cutters Q series and
UF series are those that allow the lowest values of
roughness to be obtained.

5) The polishing operation allows values of roughness averagely smaller than those of samples solely finished, to be
obtained.

_Roughness Analysis on Composite Materials_ _The Open Dentistry Journal,_ 2015 _, Volume 9_ 367

CONFLICT OF INTEREST

The authors confirm that this article content has no conflict of interest.

ACKNOWLEDGEMENTS

Declared none.

REFERENCES

[1] Malhotra N, Mala K, Acharya S. Resin-based composite as a direct
esthetic restorative material. Compend Contin Educ Dent 2011; 32:
14-23.

[2] Hossam AE, Rafi AT, Ahmed AS, Sumanth PC. Surface topography of composite restorative materials following ultrasonic scaling
and its impact on bacterial plaque accumulation. An _in-vitro_ SEM
study. J Int Oral Health 2013; 5: 13-9.

[3] Pettini F, Savino M, Corsalini M, Cantore S, Ballini A. Cytogenetic
genotoxic investigation in peripheral blood lymphocytes of subjects
with dental composite restorative filling materials. J Biol Regul
Homeost Agents 2015; 29: 229-33.

[4] Ilie N, Hickel R. Resin composite restorative materials. Aust Dent J
2011; 56 (Suppl 1): 59-66.

[5] Zimmerli B, Strub M, Jeger F, Stadler O, Lussi A. Composite materials: composition, properties and clinical applications. A literature review. Schweiz Monatsschr Zahnmed 2010; 120: 972-86.

[6] Rai R, Gupta R. _In vitro_ evaluation of the effect of two finishing
and polishing systems on four esthetic restorative materials. J Conserv Dent 2013; 16: 564-7.

[7] Sirin Karaarslan E, Bulbul M, Yildiz E, Secilmis A, Sari F,
Usumez A. Effects of different polishing methods on color stability
of resin composites after accelerated aging. Dent Mater J 2013; 32:
58-67.

[8] Egilmez F, Ergun G, Cekic-Nagas I, Vallittu PK, Lassila LV. Short
and long term effects of additional post curing and polishing systems on the color change of dental nano-composites. Dent Mater J
2013; 32: 107-14.

[9] da Silva EM, de Sá Rodrigues CU, Dias DA, da Silva S, Amaral
CM, Guimarães JG. Effect of toothbrushing-mouthrinse-cycling on
surface roughness and topography of nanofilled, microfilled, and
microhybrid resin composites. Oper Dent 2014; 39: 521-9.

[10] Dos Santos PH, Catelan A, Albuquerque Guedes AP, _et al_ . Effect
of thermocycling on roughness of nanofill, microfill and microhybrid composites. Acta Odontol Scand 2015; 73: 176-81.

[11] da Silva EM, Dória J, da Silva Jde J, Santos GV, Guimarães JG,
Poskus LT. Longitudinal evaluation of simulated toothbrushing on
the roughness and optical stability of microfilled, microhybrid and
nanofilled resin-based composites. J Dent 2013; 41: 1081-90.

[12] Corsalini M, Carella M, Boccaccio A, _et al._ An alternative approach to the polishing technique of acrylic resin surfaces. Int J
Prosthodont 2008; 21: 409-12.

[13] Corsalini M, Boccaccio A, Lamberti L, Pappalettere C, Catapano S,
Carossa S. Analysis of the performance of a standardized method
for the polishing of methacrylic resins. Open Dent J 2009; 3: 23340.

[14] Hosoya Y, Shiraishi T, Ando S, Miyazaki M, Garcia-Godoy F.
Effects of polishing on surface roughness and gloss of S-PRG filled
flowable resin composite. Am J Dent 2012; 25: 227-30.

[15] da Costa JB, Goncalves F, Ferracane JL. Comparison of two-step
versus four-step composite finishing/polishing disc systems:
evaluation of a new two-step composite polishing disc system.
Oper Dent 2011; 36: 205-12.

[16] Berger SB, Palialol AR, Cavalli V, Giannini M. Surface roughness
and staining susceptibility of composite resins after finishing and
polishing. J Esthet Restor Dent 2011; 23: 34-43.

[17] Asmussen E, Jorgensen KD. A microscopic investigation of the
adaptation of some plastic filling materials to dental cavity walls.
Acta Odontol Scand 1972; 30: 3-21.

[18] Prati C, Tao L, Simpson M, Pashley DH. Permeability and microleakage of Class II resin composite restorations. J Dent 1994;
22: 49-56.

[19] Yap AU, Yap SH, Teo CK, Ng JJ. Finishing/polishing of composite and compomer restoratives: effectiveness of one-step systems.
Oper Dent 2004; 29: 275-9.

[20] Kaminedi RR, Penumatsa NV, Priya T, Baroudi K. The influence
of finishing/polishing time and cooling system on surface roughness and microhardness of two different types of composite resin
restorations. J Int Soc Prev Community Dent 2014; 4(Suppl 2):
S99-S104.

[21] Ferraris F, Conti A. Superficial roughness on composite surface,
composite enamel and composite dentin junctions after different
finishing and polishing procedures. Part I: roughness after treatments with tungsten carbide vs diamond burs. Int J Esthet Dent
2014; 9: 70-89.

[22] Ferraris F, Conti A. Superficial roughness on composite surface,
composite-enamel and composite-dentin junctions after different
finishing and polishing procedures. Part II: roughness with diamond finishing and differences between enamel composite _vs_ body
composite. Int J Esthet Dent 2014; 9: 184-204.

[23] Heintzen SD, Forjanic M, Rousson V. Surface roughness and gloss
of dental materials as a function of force and polishing time _in vi-_
_tro_ . Dent Mater 2006; 22: 146-65.

[24] Uppal M, Ganesh A, Balagopal S, Kaur G. Profilometric analysis
of two composite resins' surface repolished after tooth brush abrasion with three polishing systems. J Conserv Dent 2013; 16: 30913.

[25] Sciammarella CA, Lamberti L, Sciammarella FM, Demelio G,
Dicuonzo A, Boccaccio A. Application of plasmons to the determination of surface profile and contact stress distribution. Strain
2010; 47: 306-23.

Received: December 30, 2014 Revised: August 17, 2015 Accepted: August 25, 2015

This is an open access article licensed under the terms of the (https://creativecommons.org/licenses/by/4.0/legalcode), which permits unrestricted, noncommercial use, distribution and reproduction in any medium, provided the work is properly cited.

본문 출처 PDF: PDF 보기 · 다른 PDF는 위 [PDF 업로드]로 올릴 수 있습니다.

활용가능성

이력 0건

아직 편집 이력이 없습니다. 저장할 때마다 이전 내용이 여기에 백업됩니다.