DOI: 10.3290/j.cjdr.b1530481, PubMed ID (PMID): 34219440Pages 79-84, Language: English
The endoplasmic reticulum has emerged as a modulator that is essential for cellular homeostasis
and human health. It is an extensive membranous organelle that acts as a hub for the
physiological and pathological processes. In recent years, it has become a topic of interest in
studies on the relationship between endoplasmic reticulum homeostasis and system diseases.
Periodontal disease is a prevalent chronic disease that affects tooth-supporting tissues, initiated
by the interaction between pathogenic bacterial infection and immune defence and resulting
in tooth loss. The endoplasmic reticulum participates in the responses to the fluctuating
microenvironments in periodontal pathogenesis and regulates periodontal homeostasis. In
this review, we present an overview of the significance of endoplasmic reticulum regulation
as a multidimensional mediator in periodontal disease and highlight the potential strategies
for periodontal regeneration.
Keywords: endoplasmic reticulum, periodontal disease, periodontal regeneration
DOI: 10.3290/j.cjdr.b1530533, PubMed ID (PMID): 34219441Pages 85-94, Language: English
Wnt signalling pathways have been the focus of intense research activity for decades due to
their fundamental role in skeletal and dental development. Wntless, an exclusive chaperone
protein for the exocytotis of Wnt ligands, was identified in 2006. In the last decade, the molecular
biological studies of Wntless and its genetic studies in human and mice have highlighted the
importance of this protein in mineralised tissues, including bone, cartilage and teeth. This article
reviews recent developments and discrepancies in the role of Wntless in skeletal and dental
development based on mutant phenotypes, as well as the underlying mechanism involved in its
molecular and physiological regulation. We conclude that, though some controversial phenotypes
exist due to different Cre line resources, Cre recombinase activity and detection time
points, Wntless undeniably exerts a context- and stage-dependent regulatory function during
the development and homeostasis of both skeletal and dental tissue.
Keywords: odontogenesis, osteogenesis, Wnt signalling, Wntless
DOI: 10.3290/j.cjdr.b1530421, PubMed ID (PMID): 34219442Pages 95-103, Language: English
Objective: To estimate the prevalence and distribution of tooth wear among groups of adolescents
and adults in Shanghai, China through an epidemiological survey, and explore the
Methods: Multistage, stratified, constant volume and cluster sampling methods were used in
an epidemiological survey conducted in Shanghai in 2014. The basic erosive wear examination
(BEWE) index was used to screen for tooth wear in different age groups: 12 years, 15
years, 18 to 35 years, 36 to 49 years and 50 to 74 years. A previously published questionnaire
collected information including dietary habits, oral hygiene habits and general conditions.
Results: This survey reports the results for 1806 participants in Shanghai. The prevalence
of tooth wear was 59.7% in adolescents (BEWE ≥ 1) and 93.1% in adults (BEWE ≥ 2). The
prevalence and severity of disease increased with age (P < 0.01). The teeth most susceptible
to wear were the central incisors and first molars. Multivariate analysis of covariance
(ANCOVA) results showed that soft drinks, alcoholic drinks, pickled vegetables and hard food,
gastroesophageal reflux disease (GERD), xerostomia and poor tooth brushing habits were
statistically correlated with tooth wear in different age groups.
Conclusion: The prevalence of tooth wear appears to be high in adolescents and adults in
Shanghai. Frequent consumption of soft or alcoholic drinks, GERD, xerostomia and poor
tooth brushing habits were positively associated with tooth wear in different age groups.
Keywords: adolescents, adults, basic erosive wear examination index, epidemiological survey, tooth wear
DOI: 10.3290/j.cjdr.b1530497, PubMed ID (PMID): 34219443Pages 105-112, Language: English
adolescents aged 12 to 15 years based on the 4th National Oral Health Survey and to explore
its associated factors.
Methods: Students aged 12 to 15 years were recruited using to a multistage stratified random
sampling method. All the subjects received oral examination and completed a questionnaire.
Information relating to OHRQoL was collected through a Mandarin version of the child oral
impacts on daily performances (Child-OIDP) questionnaire. The relationship between the
Child-OIDP scores and independent variables was assessed using a Mann-Whitney U-test,
Kruskal-Wallis test and a multivariate Poisson regression.
Results: A total of 89,582 subjects were included in the analysis, of whom 76.6% reported oral
impacts in the last 6 months. Eating was the most affected daily performance. The results of
the regression analysis showed that factors associated with adolescents’ OHRQoL included
sex, location of residence, region, only child status, parents’ level of education, frequency of
sugar consumption, self-perception of general/oral health, dental appointments in the past
12 months, oral health knowledge status, age, decayed, missing and filled teeth (DMFT)
index and number of teeth with gingival bleeding.
Conclusion: Oral impacts were common among Chinese adolescents, although most were not
so severe. Eating was the most commonly affected performance. Sex, location of residence,
region, only child status, parents’ level of education, frequency of sugar consumption, selfperception
of general/oral health status, dental appointments in the previous 12 months, oral
health knowledge status, age, DMFT index and number of teeth with gingival bleeding were
found to be associated with OHRQoL.
Keywords: adolescents, associated factors, child OIDP, China, oral health–related quality of life
DOI: 10.3290/j.cjdr.b1530507, PubMed ID (PMID): 34219444Pages 113-118, Language: English
Objective: To compare the efficiency of a new sonic powered irrigation system named EDDY
(VDW, Munich, Germany), passive ultrasonic irrigation (PUI) and conventional needle irrigation
(CNI) in root canal sealer penetration.
Methods: A total of 45 mandibular premolars were instrumented up to size 30, 0.9 taper and
randomly divided into three groups (n = 15) depending on the final irrigation activation technique:
EDDY, PUI or CNI. After the final irrigation procedures, the root canals were obturated
with labelled sealer mixed with 0.1% rhodamine B. Transverse sections at 3, 5 and 7 mm from
the root apex were examined using confocal laser scanning microscopy. The maximum depth
and total area and percentage of sealer penetration were measured using ImageJ analysis
software (National Institutes of Health, Bethesda, MD, USA).
Results: In the EDDY group, the penetration depth was higher compared to the CNI group in
the apical and middle sections and compared to the PUI group in the apical section (P ˂ 0.05).
The penetration area in the EDDY group was higher compared to the CNI group in all sections
and compared to the PUI group in the coronal section (P ˂ 0.05). The percentage of penetration
was higher in the EDDY group compared to the CNI group in all sections and compared
to the PUI group in the coronal section (P ˂ 0.05).
Conclusion: In the present study, sealer penetration was superior in the EDDY group than the
CNI group in the apical section. In the middle and coronal sections, sealer penetration was
similar for the EDDY and PUI groups.
Keywords: EDDY, passive ultrasonic irrigation, sealer penetration, sonic irrigation
DOI: 10.3290/j.cjdr.b1530491, PubMed ID (PMID): 34219445Pages 119-124, Language: English
Objective: To evaluate the microshear bond strength (μSBS) of resin cement to a lithium disilicate
glass ceramic conditioned with different surface treatment procedures.
Methods: Crystallised slices of lithium disilicate glass ceramic were randomly divided into
five groups (n = 10) according to different surface treatment procedures: the no surface treatment
(NT) group was untreated; the hydrofluoric acid (HF) group was conditioned with 4.5%
HF; the silane (S) group was conditioned with a silane coupling agent; the hydrofluoric acid
and silane (HFS) group was conditioned with HF followed by the silane coupling agent; and
the Monobond Etch & Prime (MEP) (Ivoclar Vivadent, Schaan, Liechtenstein) group was
conditioned with the one-step self-etching primer MEP. Resin cement was applied to the ceramic
surfaces and irradiated. A μSBS test was performed. Failure analysis, surface roughness
tests, surface topography examination and elemental analysis were also conducted. The data
were analysed with a one-way analysis of variance (ANOVA) and Tukey honestly significant
difference test (P < 0.05).
Results: The MEP group resulted in comparable μSBS to the HFS group (16.9 ± 4.3 MPa and
16.0 ± 2.2 MPa, respectively), but a significantly higher μSBS than the NT (1.0 ± 0.9 MPa), HF
(8.9 ± 3.9 MPa) and S (12.6 ± 2.5 MPa) groups. Adhesive failure was mainly observed in the
NT and HF groups, while the S, HFS and MEP groups demonstrated the most mixed failure.
Though micrographs revealed a roughened surface in the HF group, no significant difference
was found with any other groups.
Conclusion: Within the limitations of this study, it can be concluded that the μSBS of resin
cement to lithium disilicate glass ceramic etched with MEP is as efficient as that treated with
HF and silane.
Keywords: bond strength, lithium disilicate glass ceramic, self-etching primer, surface treatment
DOI: 10.3290/j.cjdr.b1530527, PubMed ID (PMID): 34219446Pages 125-132, Language: English
Objective: To compare the reduction of residual dentine thickness of two different post preparation
methods on the mandibular second molars with a C-shaped root canal configuration.
Methods: A total of 26 extracted right mandibular second molars with a C-shaped root canal
configuration were selected and paired based on similar canal morphology. Each of the
paired teeth was randomly allocated to the heat and ultrasonic instruments group (HU group)
or Peeso Reamer (Mani, Utsonomiya, Japan) group (PR group) (n = 13) and received post
preparation with different instruments after the same endodontic treatment. The reduction of
residual dentine thickness and the minimal remaining dentine thickness at the apical sections
at 4 or 7 mm below the cementoenamel junction (CEJ) were recorded. The data were analysed
using an independent samples t test (α = 0.05).
Results: The reduction of residual dentine thickness for the HU group was less than that for the
PR group in the two sections. Moreover, at the section 7 mm below the CEJ, the teeth reduction
of the distolingual wall in the HU group (0.022 ± 0.007 mm) was significantly lower than that
in the PR group (0.101 ± 0.013 mm) (P < 0.01).
Conclusion: Using heat and ultrasonic instruments to perform post preparation could follow
the original canal configuration to save more tooth structure in the remaining root canal wall,
minimise the reduction of residual dentine thickness and decrease the incidence of root canal
Keywords: C-shaped canal, mandibular second molars, post preparation, teeth reduction