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February 2022 Abstracts
Color stability of bulk-fill resin
composites exposed to caffeinated beverage:
Esra
Özyurt, dds & Ayşegül
Kurt, dds, phd
Abstract: Purpose: To
evaluate the in vitro color stability and surface properties of bulk-fill resin
composites after exposure to coffee and cola. Methods: Color stability was evaluated in a conventional resin
composite (Filtek Z250) and three bulk-fill resin
composites (Filtek One Bulk Fill, Tetric N-Ceram Bulk Fill, and Beautifil Bulk Fill as giomer). Color change (CIEDE 2000 ΔE00) was
calculated after 12 days of immersion in distilled water (control), coffee, or
cola (Diet Coke). Water sorption (%Wsp) and
solubility (%Wsl) ratios were calculated for each
material in each solution. One sample of each material from each condition was
observed with scanning electron microscopy and atomic force microscopy.
Generalized linear modeling and Bonferroni correction were used for ΔE00 value analysis. One-way ANOVA and Kruskal Wallis tests were performed to
analyze %Wsp and %Wsl ratios. Results: Tetric N-Ceram Bulk Fill showed the highest ΔE00 value in distilled
water. Beautifil Bulk Fill had the highest ΔE00 value in coffee and cola. Beautifil Bulk Fill had the
highest %Wsl ratio. Filtek One Bulk Fill and Tetric N-Ceram Bulk Fill had the
highest and lowest %Wsp ratios, respectively. Coffee
and cola exposure had surface property-disrupting and discoloration effects on
both conventional and bulk-fill resins. (Am
J Dent 2022;35:3-8).
Clinical
significance: Acidic beverages could negatively affect the surface properties of bulk-fill
and conventional resin composites. The usage of the giomer composite might have disadvantages in terms of esthetics.
Mail: Dr. Esra Özyurt, Trakya
University Balkan Campus, Edirne, Turkey 22030. E-mail: esraozyurt@trakya.edu.tr
Joseph Katz, dmd & Ilana Sacks
Abstract: Purpose: To
evaluate whether the prevalence of glossodynia increased among patients affected by COVID-19 compared to other hospital
populations. Methods: The i2b2 patient registry platform at the
University of Florida Health Center was used to generate a count of patients
using the international classification of diseases (ICD)-10 diagnosis codes
from October 2015 to June 2021. Logistic regression of the aggregates was used
for analysis. Results: Of the patients with both glossodynia and COVID-19, 60% were females, 32% were African American, 64% were white, and
100% were adults. There were 72% females, 19% African Americans, 72% whites,
and 93% adults with glossodynia only. For COVID-19
patients, 57% were females, 23% were African American, 56% whites, and 90% were
adults. The odds ratio (OR) for glossodynia in the
COVID-19 patients was significant (OR = 2.9; 95% CI, 1.94-4.32; P < 0.0001).
(Am J Dent 2022;35:9-11).
Clinical significance: Glossodynia is significantly more common in COVID-19 patients and should be considered in
the differential diagnoses among the oral complications of this infection.
Mail: Dr. Joseph Katz, Department
of Oral Diagnostic Sciences, University of Florida College of Dentistry, 1395
Center Drive, Gainesville, FL 32610, USA. E-*: jkatz@dental.ufl.edu
Effect of
cannabidiol oil on the color stability of resin composites
Max
Schmeling, dds, ms, phd, Neimar Sartori, dds, ms, phd & Renan
Belli, dds, ms, phd
Abstract: Purpose: To evaluate
the influence of cannabidiol (CBD) oil on the color stability of resin
composites. Methods: Three different resin composites were chosen to
prepare 90 disk-shaped specimens. The specimens were randomly selected to
compose two test groups (classic CBD or chocolate CBD) and one control group
(distilled water) for a 14-day test. Two-way ANOVA was used to evaluate the
influence of the CBD oil on the color stability of the three resin composites.
Tukey post-hoc test (HSD) was used to determine the statistical difference
among the groups. Results: ANOVA indicated statistically significant
differences among the storage solutions, resin composite, and their
correlations (P< 0.001). HSD indicated significant differences among resin
composites after staining. No difference was noticed between the color change
of the specimens immersed in classic CBD or chocolate CBD. Color differences of
the resin composites was related to the hydrophilic/hydrophobic nature of the
resin matrix. (Am J Dent 2022;35:12-14).
Clinical significance: CBD oil affected the color
stability of all the examined resin composite specimens. Considering the
obtained results, appropriate guidance should be provided to patients to
prevent potential color alteration owing to the usage of CBD oil.
Mail: Dr. Max Schmeling, Department
of Dentistry - Federal University of Santa Catarina, Brazil (UFSC), Av.
Gilberto Amado 574/201, Barra da Tijuca, Rio de Janeiro, RJ CEP: 22620-062,
Brazil. E-mail: schmeling1971@gmail.com
Photoelastic, microhardness
and roughness analysis of zirconia
Emilia
Valenzuela Espinoza, dds, msc, phd, Regina Guenka Palma-Dibb, dds, msc, phd,
Abstract: Purpose: To compare the stress distribution through photoelasticity,
microhardness and roughness of intact crowns of primary molars (CC) and the
preformed crowns of stainless steel (SSC) and zirconia (ZC) used in dental
restorations in pediatric dentistry. Methods: Six healthy primary molars were selected. For the photoelastic models, the teeth were fixed in photoelastic resin. A load of 100 N was applied, and the
models were analyzed by transmission polariscope. The Tardy method was used to quantify
the fringe order which calculates the maximum stress (T) value in each selected
point. The teeth were prepared for cementation of the crowns. The photoelastic test was repeated for each experimental crown.
Knoop microhardness was assessed on the buccal surfaces of the CCs, SSCs, and
ZCs using a microhardness tester. Parameters were 50 gf for 5 seconds.
Roughness was evaluated using a confocal 3-D laser scanning microscope/software
at 216× magnification. Roughness average (Ra) values from each model (expressed
in μm) were collected and group means were
calculated. The stress distribution, microhardness, and roughness data were
compared by using one-way ANOVA and the Tukey’s test (α= 0.05). Results: There
was no difference in the stress distribution for the CCs, SSCs and ZCs. For the
microhardness analysis, the ZCs obtained the highest values compared to the CCs
and the SSCs (P< 0.001). The CCs were significantly higher than the SSCs (P=
0.027). There was no difference in roughness for the three models (P= 0.615).
The SSCs and ZCs showed satisfactory mechanical behavior. (Am J Dent 2022;35:15-19).
Clinical significance: The
use of preformed crowns, especially those made of esthetic materials, is
currently increasing in the field of pediatric dentistry. The knowledge of
mechanical properties of stainless steel- and zirconia-prefabricated crowns
provides scientific foundation for safe clinical application, especially in
primary teeth.
Mail: Dr. Marília Pacífico Lucisano, Department of Pediatric Clinic, Faculty
of Odontology of Ribeirão Preto (US), Av. do Café,
s/n, Monte Alegre, 14040-904 Ribeirão Preto, SP, Brazil.
E-mail: marilia.lucisano@forp.usp.br
Comparison of the effectiveness of professionally
delivered
Julia Guerrero-Gironés, dds, ms, phd, Sara
Dudek, dds, Gonzalo Llambés, dds, ms, phd, María Melo, dds, ms, phd
Abstract: Purpose: To evaluate
the effectiveness of five whitening toothpastes applied three times a day for 4
weeks. Methods: 25 human extracted
teeth were selected. Two peroxide-based dental bleaching pastes (professionally
delivered): Enawhite 2.0 (En), Whitekin (Wk); and three
over the counter whitening toothpastes: Opalescence whitening toothpaste (Op),
Colgate max White expert White (Cg) Premium activated charcoal (Cr) were used.
Teeth were brushed for 4 weeks, three times a day. Color was measured with a
spectrophotometer according to the CIELab system.
∆Eab, W* and ΔE00 values were calculated at baseline, at the end of
the treatment, and 1 week after the end of treatment. Data analysis was
performed using a generalized estimating equations model, evaluating the effect
of treatment, time and interaction (P< 0.05). Results: ΔEab values ranged from
5.01 for En to 3.22 for Wk after the 4-week treatment period. One week after the end of treatment, ΔEab ranged from 5.91 for Cr to 3.62 for Op (P>
0.05 between groups). The closest to pure white (W* differences between
baseline and after 1 week from the end of treatment) was for En and Wk. ΔE00 values after 4 weeks of treatment
ranged from 3.23 for En to 1.79 for Wk. One week
after the end of treatment, the ΔE00 ranges were between 3.31 for Cr to
2.03 for Op (P> 0.05 between groups). (Am
J Dent 2022;35:20-24).
Clinical
significance: All
the evaluated whitening toothpastes improved dental color values higher than
those perceptible and acceptable at the 50:50 threshold.
Mail: Dr. María Melo, Gascó Oliag, 1, 46010 Valencia,
Spain. E-mail: mapimeal@uv.es
Effect of cigarette smoking on the color stability and
surface roughness
Ahlam Abdalla Mohamed Smew, dds, Gulhan Yıldırım, dds, phd & Melahat celik Guven, dds, phd
Abstract: Purpose: To evaluate the effect of cigarette smoking on the color stability and
surface roughness of heat-polymerized poly(methylmethacrylate)
(PMMA) and computer-aided design and computer-aided manufacturing (CAD-CAM)
PMMA denture base materials. Methods: A total of 40 disc-shaped
specimens (diameter 15 mm × thickness 2 mm) were divided into two groups
according to their processing technique: Group CC, CAD-CAM PMMA; and Group HP,
heat-polymerized PMMA. The specimens were exposed to cigarette smoke with 20
cigarettes daily for 5 days. Before the procedure, the color of the denture
base was measured using a spectrophotometer in accordance with the Commission Internationale de I’Eclairage (CIE) color system. The surface roughness (Ra) of each sample was measured five
times before and after exposure to smoke using a profilometer, and the mean
roughness (Ra) values were calculated. The color change and surface roughness
were statistically analyzed (P< 0.05). Results: Greater discoloration
was observed in the HP group, whereas the CC group showed clinically acceptable
color change. Smoking increased the surface roughness of both denture base
materials. However, the HP group had higher mean values than the CC group. (Am
J Dent 2022;35:25-29).
Clınıcal sıgnıfıcance: Denture base materials are susceptible to changes in color and surface roughness due to oral habits such as cigarette smoking. This in vitro study suggested that smoking can exacerbate the color changes and surface roughness of denture base materials, especially in heat-cured acrylic resins.
Mail: Dr. Gülhan Yıldırım, Beykent University, Cumhuriyet Mah, Turgut Özal Bulvarı Beykent Üniversitesi Diş Hekimliği Fakültesi, Büyükçekmece/Istanbul,
Turkey. E-mail: glhnchatzi@gmail.com
Influence of
cervical margin relocation with direct restorative materials
Luiz Felipe de Oliveira Pereira, dds, ms, Fabricio Perucelli, dt, ms, Evelise Machado Souza, dds, ms, phd
Abstract: Purpose: To
evaluate the in vitro marginal integrity of CAD-CAM composite inlays with the
proximal box margin relocated with different direct restorative materials
before and after thermomechanical aging. Methods: Standardized 4 mm-wide Class II cavities were prepared in 40
sound human upper molars. The mesial cervical margin was located in enamel
(control) and 1 mm occlusal to the cemento-enamel
junction (CEJ), while the distal cervical margin was located in dentin
(experimental) and 2 mm apical to the CEJ. In the experimental groups (n=10),
the distal margins were relocated up to the CEJ level by using a highly viscous
conventional glass ionomer cement (Equia Forte), low-viscosity bulk-fill
composite (SureFil SDR Flow), highly viscous nanofilled composite (Filtek Supreme XT), or a highly viscous bulk-fill composite (Filtek Bulk Fill). The inlays were milled from CAD-CAM nanohybrid composite blocks
(Brava Block) and luted with dual-cure resin cement (Allcem). The specimens were submitted to thermocycling
(5-55°C, 7,800 cycles) and fatigue loading (50 N, 1 Hz, 240,000 cycles). Epoxy
resin replicas of the margins were obtained before and after aging and evaluated
through scanning electron microscopy. The percentage of continuous margin in
relation to individual assessable margin was calculated as the marginal
integrity. The data were statistically analyzed using Wilcoxon and
Kruskal-Wallis tests (α= .05). Results: The marginal integrity
before and after aging was not significantly different (P> 0.05). Similarly,
no significant differences were observed between margins relocated with
different restorative materials in comparison to enamel margins (P> 0.05). (Am
J Dent 2022;35:30-36).
Clinical significance: Cervical margin relocation is a
valid protocol to simplify intra-oral scanning and luting of CAD-CAM composite
inlays with deep proximal margins. The marginal integrity at deep margins with
relocation material was comparable to that of enamel margins.
Mail: Dr. Rodrigo Nunes Rached, Rua Imaculada Conceição,
1155, Curitiba, PR, Brazil, 80215-901. E-mail: r.rached@pucpr.br
Effect of
different polishing systems and staining solution on surface
Helanne de Oliveira do Nascimento, dds, ms, Waldemir
Francisco Vieira Junior, dds, ms, phd,
Abstract: Purpose: To evaluate
the effect of polishing systems (discs or rubbers) on surface roughness (Ra)
and color change (∆E) of two bulk fill and one conventional resin composite
after immersion in a dye solution. Methods: 180 samples (10 mm × 2 mm) were separated into three groups: (1) Resin composite: Filtek One Bulk Fill (FO), Tetric N-Ceram Bulk Fill (TNC), Filtek Z350 XT (FXT) (n=
60); (2) polishing system: unpolished (control); aluminum oxide discs (Sof-Lex,
AOD); cup-shaped abrasive rubber polishers (Astropol,
CSA) (n= 20), and (3) immersion solutions: coffee or distilled water (n= 10).
Immersion was under 5 mL of each solution for 3 hours daily, for 30 days.
Measurement of Ra and ∆E was made considering two times: initial (after
polishing) and final (after immersion), in addition to surface analysis by
scanning electron microscopy at the end. Kruskal-Wallis, Mann-Whitney, and Dunn
(α= 0.05) was used. Results: For the unpolished samples after
immersion in coffee, TNC (P= 0.007) showed lower ΔE than FXT and FO. For
polished samples with CSA and immersed in coffee, TNC followed by FXT showed
lower ∆E than in the absence of polishing. Polishing with AOD and
immersed in coffee: FO had smaller ∆E than when not polished. For Ra, TNC
and FO had lower values after using AOD, whereas for FXT lower Ra was noted
with CSA. (Am J Dent 2022;35:37-42).
Clinical significance: The roughness and color
stability of resin composites are mediated by the polished material, polishing
system and dye solution. The best results were found for Tetric N-Ceram polished with aluminum oxide discs.
Mail: Dr. Fabiana
Mantovani Gomes França, Faculty São Leopoldo Mandic, São Leopoldo Mandic
Research Institute, Rua José Rocha Junqueira, 13 - Swift, Campinas - SP,
13045-755, Brazil. E-mail:
biagomes@yahoo.com
A new look
toward crown-to-implant ratio
Pedram
Pakzad, dds & Alireza Mosavar, msc
Abstract: Purpose: To
clarify how crown-to-implant ratio (C-I ratio) influences the bone
biomechanically with its two components: crown height and implant length. Methods: This three-dimensional finite element study was performed in two phases. The
first phase aimed to show the influence of the C-I ratio on the stresses in the
peri-implant bone and the second phase to reveal the impact of each of the two
components of the C-I ratio: crown height and implant length. During analyses,
all models were subject to three different loading conditions – axial,
buccolingual, and oblique. Results: The crown-to-implant ratio was
significantly influential on stress distribution in the peri-implant bone.
However, the crown’s height was significantly more prominent than the length of
the implant. The most substantial amount of stress was seen when long crowns
were combined with off-axial loads. Being mostly dominated by the height of the
crown and far less by the implant’s length, the C-I ratio is not balanced and
seems not to be a predictive parameter in implant dentistry. (Am J Dent 2022;35:43-48).
Clinical significance: Crown-to-implant ratio is
recommended to be assessed by its two components: crown height and implant
length because the former impacts stresses significantly more than the latter.
Mail: Dr. Pedram Pakzad, Department
of Prosthodontics, Dental Faculty, Isfahan (Khorasgan)
Branch, Islamic Azad University, Isfahan, Iran. E-mail: pakzadpedram@yahoo.com
Monitoring erosive tooth wear with
intraoral 3D scanner: A feasibility study
Alana
Cristina Machado, msc, Thaís Santiago Phillips, dds, Richard
Zimmermann, dds, Taís Scaramucci, phd
Abstract: Purpose: To evaluate
in vitro the potential of an intraoral scanner (IOS) to monitor erosive tooth
wear (ETW) using different alignment software with distinct quantitative measurement
metrics. Methods: 15 unpolished bovine crowns were exposed to citric
acid (pH ~2.5) at 24-hour intervals up to 168 hours. At baseline and after each
acid exposure episode, the teeth were scanned with IOS (3Shape TRIOS 3). Scanned
images from each data point were superimposed on baseline image using WearCompare software to obtain volume loss (mm3)
and area loss (mm2) and using IOS built-in software (3Shape TRIOS
Patient Monitoring) to obtain depth loss (mm). Pearson’s test was used to
determine the correlation between acid exposure time (h) and each outcome
measure (α= 0.05). Results: As the acid exposure time increased,
the lesion parameters (depth, volume, and area) increased. Friedman’s test
showed that relative to baseline volume loss became significant (P< 0.05)
after 72 hours from median 11.48 mm3 (IQI 25% = 8.72 mm3),
eroded area became significant (P< 0.05) from median 48.67 mm2 (IQI 25% = 44.46 mm2, P< 0.05) after 96 hours, and erosion depth
became significant (P< 0.05) from median 0.69 mm (IQI 25% = 0.66 mm2)
after 144 hours. A strong correlation was observed between depth (mm2)
and time (r= 0.9993 P< 0.0001), volume (mm3) and time (r= 0.9968,
P< 0.0001), and area (mm2) and time (r= 0.9475, P= 0.0003). (Am
J Dent 2022;35:49-54).
Clinical significance: Currently, there is no
quantitative method for clinical monitoring of erosive tooth wear. The present
study demonstrated that the intraoral scanner is a potential clinical tool for
detecting and quantitatively monitoring early and advanced erosive tooth wear.
Mail: Dr. Bennett Tochukwu
Amaechi, Department of Comprehensive Dentistry, University of Texas Health
Science Center at San Antonio, 7703 Floyd Curl Dr, San Antonio, TX 78229, USA.
E-mail: amaechi@uthscsa.edu
Effect of type 2 diabetes mellitus and periodontitis
on the Th1/Th2
Jinfeng Li, bsc, Jia Wang, msc, Xiangxin Song, msc, Zhiwei
Li, md, Yanjun Zhang, msc, Hao
Lu, msc
Abstract: Purpose: To investigate the effect of type 2 diabetes mellitus (T2DM) and periodontitis on the Th1/Th2/Th17/Treg paradigm. Methods: A total of 107 volunteers (aged 18-78 years) were recruited. Peripheral blood samples from patients with periodontitis and T2DM (n= 43), patients with periodontitis only (n= 20), patients with T2DM only (n= 23), and healthy controls (n= 21) were collected. Blood pressure, glycated hemoglobin, fasting plasma glucose, probing depth, gingival index, and clinical attachment loss were measured. The circulating proportions of Th1, Th2, Th17, and Treg cells were estimated by flow cytometry. The data were analyzed by a 2×2 factorial ANOVA. Results: We observed higher ratios of Th1/Th2 and Th17/Treg cells among patients with T2DM (P< 0.05) than among healthy controls. The proportion of Th17 cells in patients with periodontitis and T2DM was higher than that in other groups (P< 0.05). T2DM exhibited a predominant effect on the proportion of Th1 cells (F= 18.127, P= 0.000) and the Th17/Treg ratio (F= 45.384, P= 0.000). A significant "T2DM × periodontitis" interaction effect on the proportion of Th2, Th17, Treg cells, and the Th1/Th2 ratio (P< 0.05) was also noticed. The area under curve of Th17 was 0.711 (95% CI= 0.584 to 0.803, P< 0.01) in the receiver operating characteristic curve analysis. (Am J Dent 2022;35:55-60).
Clinical significance: The results suggest that the proportion of Th2, Th17, Treg cells and the Th1/Th2 ratio is indicative of immune activation and inflammation, which are evident in patients with type 2 diabetes mellitus (T2DM) and periodontitis. The data indicate that the high expression of Th17 cells may be a relevant biological factor that can be associated with an increased risk of developing chronic periodontitis in patients with T2DM.
Mail:
Dr. Xiaotao Chen, Department of Stomatology, The
People's Hospital of Xinjiang Uygur Autonomous Region, No. 91 Tianchi Road, Tianshan
District, Urumqi, Xinjiang, China. E-mail: 1440945785@qq.com
