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April 2018 Abstracts
Erosion protection efficacy of a 0.454% stannous fluoride
dentifrice
Nicola West, bds, fds rcs, phd fds (rest dent), Tao He, dds, phd, Nikki Hellin, rdn, Nicholas Claydon, bds, mscd, phd, Joon Seong, bds, mfds rcps, Emma Macdonald, hnd, bsc, msc, phd & Rachelle Eusebio, mas
Abstract: Purpose: To assess the anti-erosion effects of a 0.454% stannous
fluoride dentifrice versus a marketed dentifrice in an in situ clinical study. Methods: This was a double-blind,
randomized and controlled, two-treatment, four-period crossover clinical study
involving healthy adults. Each study period was 10 days. Subjects were
randomized to one of two dentifrice products each period: an experimental
0.454% stannous fluoride dentifrice (1,100 ppm fluoride) or a marketed 1.5% arginine-containing
dentifrice (Colgate Maximum Cavity Protection, 1,450 ppm fluoride). Subjects wore an intra-oral appliance fitted with two polished human
enamel samples for 6 hours per day, swishing with the assigned dentifrice
slurry twice a day in addition to sipping and swishing with 250 ml of orange
juice for 10 minutes (in increments of 25 ml each minute) four times each day.
Contact profilometry was used to measure surface loss
of tooth enamel over the course of the study. Two measurements for each sample
were taken at baseline and Day 10. Results: 35 subjects were randomized to treatment and 31 completed the study (mean
age = 40 years). At Day 10, enamel loss means were 0.128 µm for the stannous fluoride
dentifrice and 1.377 µm for the arginine-containing
dentifrice, respectively (P< 0.001). This represents 90.7% less enamel loss
for the stannous fluoride dentifrice. Both products were well tolerated. (Am J Dent 2018;31:63-66).
Clinical significance: The 0.454% stannous fluoride
dentifrice demonstrated significantly greater protection to human enamel
against erosive acid challenges relative to the marketed 1.5% arginine-containing dentifrice in this in situ clinical
study.
*: Prof. Nicola X.
West, Restorative Dentistry, Clinical Trials Unit, Bristol Dental School, Lower
Maudlin Street, Bristol BS1 2LY, United Kingdom. E-E-mail: N.X.West@bristol.ac.uk
Effect of pulsed ultrasound toothbrush on Streptococcus mutans biofilm
Shinya Horiuchi, dds, phd, Hiromichi Yumoto, dds, phd, Tomoko Kimura, dds, phd, Minami Sato, dds, phd,
Abstract: Purpose: To evaluate the effect of pulsed
ultrasound toothbrush on the removal of biofilm formed by Streptococcus mutans (S. mutans). Methods: S. mutans biofilm grown on apatite pellet
was destructed with four different sonic action toothbrushes: 1) pulsed
ultrasound with sonic vibration (PUV), 2) continuous ultrasound with sonic
vibration (CUV), 3) sonic vibration only (SV), and 4) no ultrasound nor sonic
vibration (control). After 3 minutes of noncontact brushing, the amount of
water-insoluble glucan was measured, and the residual
biofilm was observed by scanning electron microscopy. Results: PUV group revealed the smallest amount of the residual
water-insoluble glucans (32 ± 19%), followed by the CUV group (54 ± 12%) and the SV group (64 ± 13%). The PUV group
showed a significantly lower amount of the residual water-insoluble glucan than the SV group, while no significant difference
was found between SV and CUV. The bacterial adherence and aggregation notably
decreased in the PUV group, compared to the remaining three groups. (Am J Dent 2018;31:67-70).
Clinical significance: The sonic vibration with pulsed
ultrasound showed more reduction of the biofilm compared to the control and the
sonic vibration with and without continuous ultrasound. Thus, pulsed ultrasound
action may be beneficial for biofilm removal of interproximal regions.
Mail: Dr. Eiji Tanaka, Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences,
Tokushima University Graduate School, 3-18-15 Kuramoto-Cho,
Tokushima 770-8504, Japan. E-mail: etanaka@tokushima-u.ac.jp
An exploratory study to investigate stain build-up
with long term
Kimberly R. Milleman, rdh, bsed,
ms, Avinash Patil, msc, Martin R. Ling, bds, phd, Stephen Mason, phd
Abstract: Purpose: To monitor extrinsic stain
formation over 24 weeks with twice-daily use of an anhydrous 0.454% SnF2 dentifrice containing 5% sodium tripolyphosphate (STP) (‘Test’), compared to a standard fluoride dentifrice (0.76% fluoride as
sodium monofluorophosphate [SMFP]) (‘Comparator’)
following a professional prophylaxis. Methods: Primary efficacy variables were between-treatment differences in extrinsic
dental stain of anterior teeth after 4, 8, 12, and 24 weeks’ use using mean
area and intensity scores of the MacPherson modification of the Lobene stain index (MLSI), and to
monitor oral tolerability. Results: Overall,
214 subjects were randomized to treatment. The Test dentifrice group
demonstrated statistically significantly less stain compared with the
Comparator at each timepoint for all outcome
variables (MLSI - Area × Intensity, Area only, and Intensity only) with the
exception of MLSI (Area × Intensity) at Week 12. Products were generally well
tolerated with 26 treatment-related adverse events (TRAEs) reported (10 with
Test, 16 with Comparator). Five subjects withdrew from the 24-week study due to
TRAEs, three in the Test group, two in the Comparator
group. Statistically significantly less anterior tooth staining was observed
with up to 24 weeks twice-daily brushing with a 0.454% SnF2/5% STP
anhydrous dentifrice compared to a marketed fluoride dentifrice with 0.76%
SMFP. (Am J Dent 2018;31:71-75).
Clinical significance: Long term use of a SnF2/STP
dentifrice demonstrated minimal stain build-up after 24 weeks, twice-daily use;
products were generally well-tolerated.
Mail: Kimberly R. Milleman, 1220 Medical Park Drive, Building 4, Fort Wayne,
IN 46825 USA. E-mail: KMilleman@SalusResearch.us
Effect of ultrasonic, sonic and rotating-oscillating
powered toothbrushing
Patrícia Hernandéz-Gatón, dds, msc, phd, Regina Guenka Palma-Dibb, dds, msc, phd,
Abstract: Purpose: To evaluate the effect of ultrasonic,
sonic and rotating-oscillating powered toothbrushing systems on surface roughness and wear of white spot lesions and sound enamel. Methods: 40 tooth segments obtained
from third molar crowns had the enamel surface divided into thirds, one of
which was not subjected to toothbrushing. In the
other two thirds, sound enamel and enamel with artificially induced white spot
lesions were randomly assigned to four groups (n=10): UT: ultrasonic toothbrush
(Emmi-dental); ST1: sonic toothbrush (Colgate ProClinical Omron); ST2: sonic toothbrush (Sonicare Philips); and ROT: rotating-oscillating toothbrush
(control) (Oral-B Professional Care Triumph 5000 with SmartGuide).
The specimens were analyzed by confocal laser
microscopy for surface roughness and wear. Data were analyzed statistically by
paired t-tests, Kruskal-Wallis, two-way ANOVA and Tukey’s post-test (α= 0.05). Results: The different powered toothbrushing systems did not cause a significant increase in the surface roughness of sound
enamel (P˃ 0.05). In the ROT group, the roughness of white spot lesion
surface increased significantly after toothbrushing and differed from the UT group (P˂ 0.05). In the ROT group, brushing
promoted a significantly greater wear of white spot lesion compared with sound
enamel, and this group differed significantly from the ST1 group (P˂ 0.05).
None of the powered toothbrushing systems
(ultrasonic, sonic and rotating-oscillating) caused significant alterations on
sound dental enamel. However, conventional rotating-oscillating toothbrushing on enamel with white spot lesion increased
surface roughness and wear. (Am J Dent 2018;31:76-80).
Clinical significance: None of the powered toothbrushing systems (ultrasonic, sonic and
rotating-oscillating) tested caused significant alterations on sound dental
enamel. However, conventional rotating-oscillating toothbrushing on enamel with white spot lesion increased surface roughness and wear.
Mail: Prof. Dr. Paulo Nelson-Filho, Department of Pediatric Clinic, Faculty of Dentistry
of Ribeirão Preto, University
of São Paulo, Av. do Café s/n, Monte Alegre,
14040-904, Ribeirão Preto,
SP, Brazil. E-mail: nelson@forp.usp.br
A 12-week randomized clinical study investigating
the anti-gingivitis
Charles Parkinson, phd, Pejmon Amini, dds, Anto Jose, phd & John Gallob, dmd
Abstract: Purpose: To evaluate and compare gingival health, as measured by
a bleeding index (BI), a modified gingival index (MGI), number of bleeding
sites, and blood in expectorate following twice daily use of a non-aqueous
0.454% weight/weight (w/w) stannous fluoride dentifrice (‘Test dentifrice’)
compared to a sodium monofluorophosphate (SMFP)
dentifrice (‘Negative Control’) over 12 weeks, in subjects with moderate
gingivitis and gingival bleeding following tooth brushing. Methods: This was a single-center, examiner-blinded, randomized, stratified, two-treatment arm, parallel group, 12-week clinical
study in healthy adult volunteers with moderate gingivitis who demonstrated
gingival bleeding following tooth brushing. Subjects were assessed at baseline
for MGI, visible blood in dentifrice expectorate and BI. Following
randomization, eligible subjects underwent a thorough dental prophylaxis and
flossing. After 4 and 12 weeks of twice daily brushing with their allocated
treatment, subjects returned to the site for MGI, visible blood in dentifrice
expectorate, and BI assessments. Results: Of 317 screened subjects, 253 were randomized, and 238 completed the study.
Statistically significant differences between treatments were observed in favor
of the Test dentifrice compared to the Negative Control dentifrice in terms of
gingival bleeding (number of bleeding sites and bleeding index), and visual
signs of gingival inflammation (MGI) (P< 0.0001 at Weeks 4 and 12 for all).
The visual assessment of the level of blood in expectorate following brushing
demonstrated large reductions from baseline, however no significant difference
between treatments was observed. Treatments were generally well tolerated. (Am J Dent 2018;31:81-85).
Clinical significance: Use of a
dentifrice containing 0.454% w/w stannous fluoride led to significantly greater
control of gingivitis (gingival bleeding and visual signs of gingival
inflammation) compared to a SMFP dentifrice over a 12-week period. This study
was conducted in subjects with moderate gingivitis and in a population
represented by individuals who experience gingival bleeding on brushing, and is
therefore considered representative of individuals who may opt for treatment
therapies in the form of a daily use toothpaste.
Mail: Dr. Charles Parkinson, GSK Consumer
Healthcare, St George’s Avenue, Weybridge, KT13 0DE,
United Kingdom. E-mail: charles.x.parkinson@gsk.com
Physical and biological properties of a newly
developed
Liang Chen, phd, Jie Yang, phd, Rebecca
Wang, ms & Byoung In Suh, phd
Abstract: Purpose: To evaluate the physical and biological properties of a
novel calcium silicate-based self-adhesive resin cement (TheraCem)
by comparison with a traditional self-adhesive resin cement (UniCem 2) and a resin-modified glass-ionomer cement (FujiCEM 2). Methods: pH of the cements was measured with moist pH strips. Antimicrobial activity
was evaluated by a modified disk diffusion assay. Calcium release of TheraCem in water or lactic acid was measured with an ion selective pH meter for 56 days. Shear bond strength of
the cements to zirconia after incubation in water or
lactic acid for 7 days was assayed according to ISO 29022:2013, and the
fractured surface of zirconia and cement were
observed with a stereomicroscope and a scanning electron microscope,
respectively. Results: TheraCem started with an acidic pH value of 4.0 and
stabilized at pH 9.0, whereas the other two cements remained acidic. TheraCem and FujiCEM 2 displayed
antimicrobial activity, but not UniCem 2. Calcium
release was observed from TheraCem, which was higher
in lactic acid than in deionized water. TheraCem showed highest shear bond strength to zirconia among the three cements, which was not impaired by
incubation in lactic acid. In contrast, bond strength of UniCem 2 and FujiCEM 2 decreased significantly under the
acidic condition. Consistently, scanning electron micrographs demonstrated
marginal degradation of UniCem 2 and FujiCEM 2, but not TheraCem,
samples in the acid. The results suggest that TheraCem had features that would help reduce or prevent secondary caries. (Am J Dent 2018;31:86-90).
Clinical significance: The new calcium silicate-based
self-adhesive resin cement, TheraCem, had an alkaline
pH and could be desirable in clinical applications with advantages such as bond
strength and stability, antimicrobial activity, as well as calcium release.
Mail: Dr.
Liang Chen, BISCO, Inc., 1100 W. Irving Park Road, Schaumburg, IL 60193 USA. E-mail:
lchenchem@yahoo.com
Effects of various polishing techniques and thermal
cycling on the surface
Burcu Acar, dds & Ferhan Egilmez, dds, phd
Abstract: Purpose: To investigate and compare the effects of several
polishing systems and thermal cycling on the surface roughness and color change
of various polymer-based CAD/CAM materials. Methods: Bar-shaped specimens (GC CeraSmart,
CS; Lava Ultimate, LU and Vita Enamic, VE) were
prepared. All specimens were polished with SiC papers. The specimens in Group A served as control and no additional surface
polishing was applied. Final polishing was performed using diamond polishing
paste (Diapolisher Paste) in Group B. In Group C,
aluminum oxide abrasive discs (Sof-Lex XT Pop on)
were used. Group D was polished with diamond impregnated spiral polishing
system (EVE Diacomp Plus Twist). In Group E,
polishing was done with rubber-based silicon abrasives (Polydentia).
Thereafter, the specimens were submitted to thermal cycling. The surface
roughness and color measurements were performed. Kruskal-Wallis
and the Mann-Whitney U tests were applied for the evaluation of ΔE00 data.
Ra data were evaluated using three-way ANOVA. Pearson’s correlation between Ra
and ΔE00 was further investigated. Results: Neither the CAD/CAM materials nor thermal cycling affected
the Ra data (P> 0.05). In contrast, significant difference was found among
the polishing methods (P< 0.001). On the other hand, VE showed the highest
color change whereas LU showed the lowest (P< 0.05). Additional-ly, the specimens in Group D exhibited significantly higher
color change than other tested groups (P< 0.05). A moderate positive
correlation was seen between Ra and ΔE00 data of LU (rho = 0.390, P=
0.01). (Am J Dent 2018;31:91-96).
Clinical significance: The diamond impregnated
two-stage polishing procedure may not be an appropriate method for the tested CAD/CAM
materials, as it resulted in the highest color change. On the other hand, all
tested materials exhibited visually perceptible, but clinically acceptable
color changes following the different polishing techniques. Additionally,
diamond paste polishing could be a clinically acceptable procedure in terms of
surface roughness.
Mail: Dr.
Ferhan Egilmez, Mutlukent Mah. 10, Cadde 2065, Sk. No:15, Beysukent-Ankara, Turkey. E-mail: ferhanegilmez@gmail.com
Retention of CAD/CAM resin composite crowns
following different
Amir H. Nejat, dds, ms, Jinwhan Lee, phd, Shreya Shah, bds,
ms, Chee Paul Lin, phd, Prajakta Kulkarni, dds,
Abstract: Purpose: To evaluate the effect of different surface treatments
and primers with a CAD/-CAM resin composite block on its crown retention. Methods: 120 human molars were prepared
with a 24° total convergence angle, 1.5 mm height, and axial walls in dentin.
Surface area was measured by digital microscopy. Crowns were machined from CAD/CAM
resin composite blocks. Teeth were randomly allocated to 12 groups (n= 10)
based on possible combinations of three surface treatments: [Control, Alumina
air abrasion (50-µm Al2O3 at 0.28 MPa)];
5% hydrofluoric acid etch (20-second scrub); silane application (with or without Kerr Silane primer); and
adhesive application (with or without Optibond XTR
Adhesive). Optibond XTR Adhesive was applied to the
tooth preparations and crowns were bonded with MaxCem Elite cement. Crowns were fatigued for 100,000 cycles at 100 N in water and debonded in tension (1 mm/minute). Crown retention strength
(maximum load/surface area) values were analyzed using a three-way ANOVA with Tukey's post-hoc tests (α= 0.05). Results: Surface treatment, silane and
adhesive applications independently affect retention force (P< 0.05). All
interactions were not significant (P> 0.05). Alumina airborne abrasion
surface treatment, silane and adhesive applications
all improve retention strength. Therefore, CAD/CAM resin composite crowns can
withstand debonding while undergoing mechanical fatigue. Although all forms of
surface treatment and primer application improve bond strength, the highest
mean retention strength values were recorded when the crowns were alumina
particle abraded and coated with adhesive (with or without silane).
(Am J Dent 2018;31:97-102).
Clinical significance: In order to improve the bonding
of resin composite crowns, application of alumina airborne particle abrasion
and a coat of adhesive (proceeded by an optional coat of silane)
is recommended. If hydrofluoric acid is utilized, the crowns should be treated
with a coat of silane followed by adhesive application.
Mail: Dr. Amir H. Nejat, SDB 3339, 1100 Florida Ave., New Orleans LA 70119,
USA. E-mail: anejat@lsuhsc.edu
Fluoride activity of antibacterial ammonium hexafluorosilicate solution
Toshiyuki Suge, dds, phd, Shingo
Shibata, dds, phd, Kunio Ishikawa, phd & Takashi Matsuo, dds, phd
Abstract: Purpose: To evaluate the acid resistance of various antibacterial ammonium hexafluorosilicate (SiF)
solutions. Methods: Antibacterial SiF solutions were prepared with the addition of chlorhexidine (CHX), cetylpyridinium chloride (CPC), isopropyl methylphenol (IPMP), or epigallocatechin gallate (EGCG). Hydroxyapatite pellets were treated with SiF solution with or without antibacterial agents for 3
minutes. The demineralized depth of hydroxyapatite pellets after SiF treatment was measured using a surface roughness analyzer. Results: SiF+CPC solution showed
equivalent acid resistance to SiF and AgF treatment. In contrast, the original acid resistance
activity of SiF solution was diminished by the
addition of other antibacterial agents (CHX, IPMP and EGCG). SiF with the addition of CPC was the most effective for
reducing the demineralized depth, showing the same
levels as those of SiF and AgF.
(Am J Dent 2018;31:103-106).
Clinical significance: The addition
of CPC to the SiF solution did not reduce its
fluoride activity, indicating that it may be useful for the prevention of
dental caries. SiF with added antibacterial agents
may have the potential to prevent dental caries.
Mail: Dr.
Toshiyuki Suge, Department of Conservative Dentistry,
Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto, Tokushima 770-8504, Japan. E-mail: suge@tokushima-u.ac.jp
Sealing of restorations with marginal defects does
not affect their longevity
Juan Estay Larenas, dds, phd, Javier
Martin Casielles, dds, ds, phd, Patricio Vildósola Grez, dds, ds, phd,
Abstract: Purpose: To evaluate sealed amalgam and resin-based composite restorations after
12 years to determine whether sealing minor defects (micro-repairs) enhanced
the longevity of restorations. Methods: 34
subjects aged 18-80 were recruited. This sample group underwent 137
restorations, including 51 resin-based composite (RC) and 86 amalgam (AM)
restorations. Existing restorations with localized, marginal defects were
assigned to one of two groups: (a) the Sealing group (n=48, 27 AM; 21 RC) or
(b) the Control group (n=89, 59 AM; 30 RC). The quality of each restoration was
scored according to the modified USPHS criteria by two examiners at the
beginning of the study and after 1-5, 10, and 12 years. Kaplan Meier survival
curves were created and a Cox regression was applied to investigate survival
variables. Mantel Cox, Wilcoxon, and Friedman tests
were performed for comparisons within groups. Results: After 12 years, no statistically significant differences were
observed for the variables “restorative material” (P= 0.538) or “sealing
yes/no” (P= 0.136) with respect to the longevity of the restorations. All
groups behaved similarly with regard to marginal adaptation, secondary caries,
and tooth sensitivity (P≥ 0.05). Cumulatively, after a 12-year
observation period, sealing minor restoration defects did not affect the
longevity of the restorations. (Am J Dent 2018;31:107-112).
Clinical significance: Sealing minor marginal defects
for resin composites or amalgam restorations did not affect their longevity.
This intervention may be considered over-treatment for patients with
low-to-medium risks for developing dental caries.
Mail: Dr. Eduardo Fernández G., Department of Restorative Dentistry, University
of Chile, Dental School, Sergio Livingstone Pohlhammer 943, Independencia, Santiago, Chile and Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile. E-mail: edofdez@yahoo.com
