Thioredoxin and metallothionein: Homeostasis-related proteins in lip carcinogenesis

ObjectiveThioredoxin (Trx) and metallothionein (MT) are involved in the development of some carcinomas; however, the role of these proteins in labial carcinogenesis has not yet been tested. The aims of the study were to evaluate and to correlate the immunoexpression of Trx and MT in actinic cheilitis, lip squamous cell carcinoma, and normal vermillion lip mucosa.DesignImmunohistochemistry was undertaken for Trx and MT in samples of actinic cheilitis, lip squamous cell carcinoma, and normal lip mucosa. Qualitative and semi-quantitative evaluations were conducted. The proportion of stained cells, intensity of staining, and the cell compartment labeled were evaluated. A quickscore index was also calculated by multiplying the values of extension and intensity of nuclear and cytoplasmic staining, respectively, giving a maximum value of 9. Statistics were performed.ResultsA remarkable nuclear Trx staining was seen in normal lip mucosa and cheilitis, not in carcinoma (p < 0.05). Cytoplasmic Trx expression was widely detected in all lesions (p > 0.05). MT was broadly expressed in nuclei and cytoplasm of carcinoma, but not in normal lip mucosa and cheilitis (p < 0.05). Quickscores were in accordance with the qualitative results.ConclusionsThe current study showed a different immunopattern of Trx and MT between normal lip mucosa, actinic cheilitis and lip squamous cell carcinoma. The cellular compartment-based analyses evidenced differences that can be related to the proteins function. Considering the relevant roles of these proteins in cellular homeostasis, they seem to have an important role in lip carcinogenesis.     

Usefulness of contrast-enhanced CT in the evaluation of depth of invasion in oral tongue squamous cell carcinoma: comparison with MRI

Objectives

There is currently no standardized approach for assessing the depth of invasion (DOI) of oral tongue squamous cell carcinoma via diagnostic imaging. We investigated the usefulness of contrast-enhanced computed tomography (CECT) for estimating the pathological DOI of oral tongue squamous cell carcinoma by evaluating the correlation of pathological DOI with the DOIs on CECT and magnetic resonance imaging (MRI).

Methods

We retrospectively reviewed 21 of 139 patients who underwent radical surgery for primary oral tongue squamous cell carcinoma between 2009 and 2018. The 21 cases were evaluable, without dental artifacts on CECT. DOIs on CECT and MRI, and pathological DOI were measured.

Results

The median pathological DOI was 9 mm, that on CECT was 10.9 mm, that on T2-weighted MRI was 14.2 mm, and that on contrast-enhanced T1-weighted MRI was 13.1 mm. The DOIs on CECT and on MRI were larger than the pathological DOI (p?=?0.003 to <?0.001). The absolute value of the difference between pathological DOI and DOI on CECT was smaller than that between pathological DOI and DOI on MRI (p?=?0.01 and 0.003). DOIs on CECT and on MRI correlated with pathological DOI (r?=?0.74–0.66, all p?<?0.001). Spearman’s correlation coefficient between DOI on CECT and pathological DOI was greater than that between DOI on MRI and pathological DOI.

Conclusions

Compared to the DOI determined on an MRI scan, the DOI determined on a CECT scan correlated with and better approximated pathological DOI. Therefore, CECT can be useful for preoperative staging of patients with oral tongue squamous cell carcinoma.

     

Changes in facial profile during orthodontic treatment with extraction of four first premolars

The present study was designed to evaluate soft tissue profile changes after the orthodontic treatment of class I bimaxillary dentoalveolar protrusion in adult cases. Pre- and post-treatment cephalograms of 20 Caucasian female class I bimaxillary dentoalveolar protrusion patients were selected from private practice. All of them were treated by extraction of four first premolars, and banded and bonded by 022 × 028 standard edgewise technique. t-Test was used to analyze pre- and post-treatment cephalograms. This study showed that upper and lower lip protrusions were decreased respectively 2.7 ± 2.9 mm (p < 0.001) and 2.8 ± 2.8 mm (p < 0.001). The mean changes of upper and lower lip thickness and length, as well as nasolabial and labiomental angles were not significant. Significant positive correlation was found between changes of maxillary and mandibular incisors with changes in upper lip (r_UI = 0.70, p < 0.001, r_LI = 0.59, p < 0.006) and the lower lip positions (r_UI = 0.64, p < 0.002, r_LI = 0.72, p < 0.001). By using stepwise regression it was found that a ratio of 0.63:1 was obtained between upper lip retraction and maxillary incisor retraction and a ratio of 0.62:1 was obtained between lower lip retraction and mandibular incisor changes. This study concluded that, a strong correlation exists between anterior tooth retraction and the position of both lips.     

In situ effect of a CPP-ACP chewing gum on enamel erosion associated or not with abrasion

Objectives

The purpose of this study is to analyze the in situ effect of a casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP) chewing gum on human enamel erosion lesion associated or not with abrasion.

Material and methods

A three-way crossover study of 7 days was conducted involving 10 volunteers subjected to the same protocol: (G1) CPP-ACP sugar-free chewing gum, (G2) regular sugar-free chewing gum without CPP-ACP, and (G3) saliva—no chewing gum. An abrasion test was included in each phase. A 3D non-contact profilometry measurement of lesion depth and surface roughness was obtained of sound and eroded surfaces. A salivary calcium concentration was determined for all volunteers. ANOVA followed by Tukey’s test were used with a p < 0.05.

Results

The enamel depth and the enamel surface roughness of the CPP-ACP gum group were significantly lower than the others (ANOVA, p < 0.05). No significant differences were observed between the treatments when associated with abrasion (p > 0.05). A positive and significant correlation was seen between the lesion depth and enamel surface roughness for GI (r = 0.87, p = 0.00) and GIII (r = 0.79, p = 0.00) groups. The estimated total calcium presented in the saliva after the chewed CPP-ACP gum showed no statistical significance between the mean absorbance values at the different time collections (p > 0.05).

Conclusions

It is demonstrated that the incorporation of the CPP-ACP into a sugar-free gum significantly increased the remineralization/protection of eroded enamel surface.

Clinical relevance

The CPP-ACP added to gum may be a suitable alternative vehicle, to deliver calcium ions to saliva and therefore protecting enamel.

     

The relationship between ezrin and podoplanin expressions in keratocystic odontogenic tumors

Background

The aims of this study were to investigate the immunolocalization of ezrin and its relationship with the podoplanin expression in keratocystic odontogenic tumors.

Material and Methods

The immunohistochemical expressions of ezrin and podoplanin by odontogenic epithelium were evaluated in keratocystic odontogenic tumors using monoclonal antibodies.

Results

Our results showed strong cytoplasmic ezrin and membranous podoplanin expressions in basal epithelial layer of all keratocystic odontogenic tumors. The cytoplasmic and membranous ezrin expressions were also detected in suprabasal epithelial layers of tumors. Statistically significant difference between cellular immunolocalization of ezrin and podoplanin odontogenic epithelium were found by Wilcoxon’s test (p < 0.05). No correlation between both proteins in keratocystic odontogenic tumors was detected by Spearman test.

Conclusions

These results suggest that ezrin and podoplanin may contribute to the expansive growth and local invasiveness of keratocystic odontogenic tumors. Additionally, as both proteins were overexpressed by odontogenic epithelium, their possible roles need to be further explored in benign odontogenic tumors.

     

Expression of CD44 (NKI-P1) in oral squamous cell carcinoma associated vascular endothelial cells: A relationship to tumor angiogenesis

BackgroundOral squamous cell carcinoma is characterized by high degree of local invasion with metastasis as well as characteristic angiogenic features. Angiogenesis is a critical step in the growth and metastasis of tumors. Cluster of differentiation 44 (CD44) is a cell surface glycoprotein which is widely expressed in both physiological and pathological conditions.AimThe study was designed to assess the expression of CD44 (NKI-P1) in oral squamous cell carcinoma associated endothelial cells and to correlate this expression with matrix metalloprpteinase-9 (MMP-9) and transforming growth factor-beta (TGF- β) expression immunohistochemically.Materials and methodsOne hundred fourteen archival oral squamous cell carcinoma cases were used in this study. Immunohistochemistry was performed for CD44 (NKI-P1), Ki-67, cluster of differentiation 31(CD31), podoplanin (D2-40), MMP-9 and TGF- β. Microvessel density was also determined morphologically. Results: CD44 was expressed in (CD31+/ Podoplanin –) blood vascular endothelial cells in a strong cytoplasmic fashion. In addition, the extracellular matrix proteins (MMP-9 and TGF-β were expressed in oral squamous cell carcinoma stroma which was enriched with CD44 + blood vessels. The mean numbers of microvessel density in connective tissue beneath normal epithelium and different grades of oral squamous cell carcinoma stroma were 5.8, 22.1, 22.4 and 23.5, respectively with the P-value < 0.05, where a significant statistical difference between microvessel density in the connective tissue beneath normal epithelia and stroma of all grades of oral squamous cell carcinoma was found. Conclusion: CD44 (NKI-P1) is considered a potential marker of oral squamous cell carcinoma angiogenesis and it can be used as a valuable biomarker of tumor invasion and as a therapeutic target for anti-angiogenic therapies.     

Impact of pretherapeutic neutrophil-to-lymphocyte ratio,serum albumin,body-mass index,and advanced lung cancer inflammation index on clinical outcome in sinonasal squamous cell carcinoma

BackgroundSquamous cell carcinoma of the nasal cavity and paranasal sinuses is a rare and aggressive cancer entity with poor survival rates. Data on this group of head and neck tumors are scarce. Inflammation and cachexia-based markers and their impact on clinical outcome have been studied in several cancer groups. The aim of this study was to evaluate their prognostic potential in sinonasal squamous cell carcinoma.Patients and methodsThis retrospective analysis included all patients treated for sinonasal squamous cell carcinoma at a tertiary referral center between 2002 and 2015. Patients were divided into groups with low and high pretherapeutic values based on the values of serum albumin (ALB, median 41.6 g/l), neutrophil-to-lymphocyte ratio (NLR, median 3.5), body-mass index (BMI, median 24.7), or advanced lung cancer inflammation index (ALI, median 29.5). Main outcome measures were overall survival (OS) and disease-free survival (DFS). Statistical analysis included calculation of survival differences using log-rank tests, hazard ratios (HR), and respective 95% confidence intervals (CI).Results41 patients were included. Low ALB values did not influence OS (median OS not reached in both groups; p = 0.59, HR = 0.75, CI = 0.3–2.1) or DFS (median DFS 0.9 years vs 2.2 years; p = 0.6, HR = 0.8, CI = 0.4–1.8). High NLR was significantly associated with worse OS rates (median OS not reached vs 1.7 years, p = 0.02, HR = 3.4, CI = 1.0–108) but with no influence on DFS (median DFS 3.1 years vs 0.8 years; p = 0.15, HR = 1.8, CI = 0.8–4.2). Similar results were observed for patients with low ALI (median OS 1.7 years vs not reached; p = 0.03, HR = 0.3, CI = 0.1–0.9 and median DFS 0.8 years vs 2.2 years; p = 0.58, HR = 0.8, CI = 0.3–1.8). BMI was the strongest prognosticator in our study. Low pretherapeutic BMI was linked to significantly worse OS (median OS 1.4 years vs not reached; p = 0.003, HR = 0.2, CI = 0.0–0.6) and DFS (median DFS 0.8 years vs not reached; p = 0.02, HR = 0.4, CI = 0.2–0.8). In multivariate analysis BMI was revealed as an independent marker for OS (p = 0.015). No marker reached the level of significance in regard to DFS in multivariate analysis.ConclusionPretherapeutic BMI had a superior prognostic value in patients with sinonasal squamous cell carcinoma in comparison with other tested variables. BMI may be a simple tool for estimating clinical outcome in SNSCC. However, larger studies are necessary to validate our results.     

Physical and mechanical properties of dual functional cements—an in vitro study

Objectives

The aim of this study was to evaluate the physical and mechanical properties of different dual functional cements.

Materials and methods

Three dual functional cements (Allcem Core (FGM), Rebilda DC (VOCO), and LuxaCore Z (DMG)), a luting resin cement (Rely X ARC (3 M ESPE)), and a Core Buildup composite resin GrandioSo (VOCO) were used. Flexural strength (n = 10) and film thickness (n = 6) were evaluated according to ISO 4049:2009. Flow (n = 6) was evaluated according to ISO 6876:2001. Degree of conversion (DC) was assessed immediately and 24 h after polymerization (n = 5). For resistance to dislodgment (RD) analysis, bovine teeth were prepared to receive fiber glass posts, and a push-out test (n = 12) was used.

Results

Luxacore Z presented lower flexural strength when compared to GrandioSo (p < 0.001). No statistical difference was found between cements for film thickness (p = 0.66). Reduced flow values were found for Allcem Core (p = 0.006). No statistical difference was found for immediate DC for different cements (p > 0.05). After 24 h, DC increased for all groups, except for Luxacore Z (p = 0.054). The RD did not differ from the control Rely X ARC, regardless of the root third (p > 0.05). Luxacore Z showed lower mean values in the apical third compared to the coronal third (p = 0.046).

Conclusions

The dual functional cements (Allcem Core and Rebilda DC) possessed similar physical and mechanical properties of luting resin cement (RelyX ARC) and Core Buildup composite resin (GrandioSo). Hence, they could be used for one-stage post and core buildup restorations.

Clinical relevance

The dual functional cements could be used for one-stage post and core buildup restorations since they possess similar physical and mechanical properties of luting resin cements and Core Buildup composite resin.

     

Cranio-maxillofacial reconstruction with microvascular radialis flaps—parameters and correlations of postoperative pain management

Objectives

Postoperative pain management is of highest interest for patients undergoing maxillofacial surgery including microvascular reconstructive surgery. Currently, there is a lack of information regarding process and outcome of postoperative pain management after microvascular reconstruction.

Materials and methods

In a prospective clinical study, 31 adults were evaluated on the first postoperative day following microvascular reconstruction with a radial forearm flap using the standardized questionnaire of the Germany-wide project Quality Improvement in Postoperative Pain Management (QUIPS). It enables a standardized assessment of patients’ characteristics, pain parameters, outcome and pain therapy process parameters.

Results

Pain management consisted predominately of premedication with midazolam, sufentanil and metamizol intraoperatively, piritramid in the intensive care unit and metamizol, tramadol and fentanyl patches on ward. Nineteen patients (61.3 %) showed inadequate pain management with pain levels ≥4. Among other significant relations, patients exhibiting an age below the median presented significant higher levels of pain under strain (p = .041) and maximum pain (p = .006) as well as rate of breathing (p = .009) and mood (p = .006) disturbance. Performance of pain counselling showed specific impact on pain under strain (p = .008), maximum pain (p = .004) and satisfaction with pain intensity (p = .001). Whether microvascular reconstruction was performed with primary or secondary intention or performance of a neck dissection did not show significant influence.

Conclusions

QUIPS helped us to adequately evaluate the procedure-specific quality of postoperative management following microvascular reconstruction with a radial forearm flap. It helped us to identify a surprisingly high amount of inadequate pain management. Postoperative pain levels seem to be primarily influenced by the performed reconstruction.

Clinical relevance

Establishment of a continuous and procedure-specific evaluation of postoperative pain levels should help to avoid inadequate pain management, which is widely prevalent according to the literature and our study. Preoperative pain counselling is essential and should be procedure specific to be its best.

     

Glass hybrid,but not calcium hydroxide,remineralized artificial residual caries lesions in vitro

Objectives

For deep carious lesions, less invasive carious tissue removal is recommended. The resulting residual carious lesions might benefit from remineralization by lining or restoration materials. We aimed to compare mineral gains in artificial residual lesions provided by calcium hydroxide and glass hybrid materials in combination with pulpal fluid simulation.

Methods

On the coronal aspect of human dentin discs (n = 20), artificial carious lesions were induced using acetic acid. Median mineral loss ΔZ [25th/75th percentiles] of resulting lesions was 1643 [1301/1858] vol% μm. One third of each disc served as baseline sample. The remaining disc was divided into four groups, each being covered with one experimental material (n = 20/group): flowable composite (control (CO)), setting or non-setting calcium hydroxide liner plus flowable composite (CH-S, CH-NS), and glass hybrid (GH). Samples were mounted in a dual-chamber device. Pulpal surfaces were exposed to simulated pulpal fluid at 2.94 kPa. Coronal surfaces were exposed to artificial saliva and rinsed with 200 ppm NaF every 2 weeks. After 12 weeks, mineral loss differences (ΔΔZ) were assessed using transverse microradiography. Electron probe microscopic analysis was used to measure fluoride and strontium concentrations.

Results

Mineral gains were not significantly different between CO (ΔΔZ = 372 [115/501] vol% μm), CH-S (ΔΔZ = 317 [229/919] vol% μm), or CH-NS (ΔΔZ = 292 [130/579] vol% μm; p > 0.05/Wilcoxon test) but significantly increased in GH (ΔΔZ = 1044 [751/1264] vol% μm, p < 0.001). Samples in GH showed fluoride and strontium enrichment deep into the dentin. Such enrichment was not found in CO.

Conclusions

Within the limitations of this study, GH, but not calcium hydroxide, provided coronal remineralization of residual carious lesions.

Clinical relevance

Glass hybrids might provide additional remineralization of residual carious lesions. The functional implications of this mineral gain need to be evaluated.

     

E-cadherin and β-catenin expression in well-differentiated and moderately-differentiated oral squamous cell carcinoma: relations with clinical variables

The aim of this study was to establish the expression and localisation of E-cadherin and β-catenin in oral squamous cell carcinomas (SCC) so that we could correlate the findings with prognostically-relevant clinicopathological variables. E-cadherin and β-catenin expression in normal oral mucosa and in oral squamous cell carcinomas were examined immunohistochemically, and their association with clinicopathological factors and prognosis were then analysed in 69 patients who had been operated on for oral SCC. E-cadherin expression was found in all 69 cases: in 11 cases (16%) it was weak; in 21 (30%) moderate, and in 37 (54%) high. β-Catenin expression was found in 64 cases (93%): in 18 cases (26%) cell-membrane expression was weak; in 26 (38%) it was moderate; in 19 (28%) it was high, and in one case (1%) there was cytoplasmic staining. No nuclear staining was detected. E-cadherin was significantly associated with histological grade (p = 0.002) and alcohol consumption (p = 0.05), and β-catenin was significantly associated with nodal stage (p = 0.02), TNM stage (p = 0.009), and E-cadherin expression (p = 0.01). However, none of them were independent prognostic factors in the disease-specific survival analysis. E-cadherin is closely linked to β-catenin expression in oral SCC and to tumour differentiation. Alcohol consumption could increase the aggressiveness of SCC, leading to reduced expression of E-cadherin. β-catenin could be an early marker for the identification of occult metastases in patients with oral SCC.     

Study of the participation of MMP-7, EMMPRIN and cyclophilin A in the pathogenesis of periodontal disease

Background and objectivePeriodontal disease is an infectious disease resulting from the immunoinflammatory response of the host to microorganisms present in the dental biofilm which causes tissue destruction. The objective of this study was to evaluate the immunohistochemical expression of matrix metalloproteinase 7 (MMP-7), extracellular matrix metalloproteinase inducer (EMMPRIN) and cyclophilin A (CypA) in periodontal disease.DesignGingival tissue samples were divided as follows: clinically healthy gingiva (n = 32), biofilm-induced gingivitis (n = 28), and chronic periodontitis (n = 30). Histological sections of 3 μm were submitted to immunoperoxidase method and undergone quantitative analysis. The results were analyzed statistically by the Mann-Whitney and Spearman correlation tests, with the level of significance set at 0.05 (α = 0.05).ResultsImmunopositivity for MMP-7, EMMPRIN and CypA differed significantly between the three groups, with higher percentages of staining in chronic periodontitis specimens, followed by chronic gingivitis and healthy gingiva specimens (p < 0.05). Immunoexpression of CypA and MMP-7 was higher in the intense inflammatory infiltrate observed mainly in cases of periodontitis (p < 0.05). CypA expression was positively correlated with MMP-7 (r = 0.831; p < 0.001) and EMMPRIN (r = 0.289; p = 0.006). In addition, there was a significant positive correlation between probing depth and expression of MMP-7 (r = 0.726; p < 0.001), EMMPRIN (r = 0.345; p = 0.001), and CypA (r = 0.803; p < 0.001).ConclusionThese results suggest that MMP-7, EMMPRIN and CypA are associated with the pathogenesis and progression of periodontal disease.     

The time-course change in the lip closing force in Class III malocclusion after orthognathic surgery

ObjectivesThe purpose of this study was to examine the changes with time in lip pressure after orthognathic surgery for skeletal Class III patients.Study designThe subjects consisted of 63 patients (32 female and 31 male) diagnosed with mandibular prognathism who underwent sagittal split ramus osteotomy with and without Le Fort I osteotomy. Maximum and minimum lip closing forces were measured with Lip De Cum^®. The changes with time were compared statistically.ResultsThe maximum and minimum lip closing force increased time-dependently in men and women after surgery and there were significant differences between men and women with changes with time in the maximum lip closing force (p = 0.0086) and the minimum lip closing force (p = 0.0302). After 1 year, the Class III group maximum lip closing force was significantly smaller than the control group in both men (p < 0.0001) and women (p < 0.0001).ConclusionsThis study suggests that there was significant difference in over time in the lip closing force between men and women in Class III patients. Although the maximum lip closing force increased with time, it did not reach the level of the control group after 1 year.     

Association of ENAM gene single nucleotide polymorphisms with dental caries in Polish children

Objectives

The objective of this study was to prove the association between dental caries and single nucleotide polymorphisms (SNPs) in the ENAM gene.

Material and methods

The research was carried out in 96 children (48 with caries and 48 counterparts free of this disease), aged 20–42 months, with 11–20 erupted teeth. All children were from four day nurseries located in Poznan. The study included the dental examination to select individuals to the research and oral swab collection for molecular evaluation. Seven selected SNPs markers of the ENAM gene were genotyped, five using TaqMan probe assay (rs2609428, rs7671281, rs36064169, rs3796704, and rs12640848) and two by Sanger sequencing (rs144929717 and rs139228330).

Results

Statistically significant higher prevalence of the alternative G allele and the alternative GG homozygote in the control group in comparison with the caries group in SNP rs12640848 was observed, respectively, p = 0.0062 and 0.0010. Although the prevalence of the AG heterozygote was higher for the caries subjects in comparison with controls (OR = 2.9), and the result was statistically significant (p = 0.0010), the overall prevalence of the G allele for this SNP was significantly higher in control group (OR = 2.3; p = 0.0062).

Conclusions

The study revealed the strong association between rs12640848 marker of ENAM gene and caries susceptibility in primary teeth in children from Poznan.

Clinical relevance

The presence of SNPs in the ENAM gene may be important as suspected predictive factor of dental caries occurrence in children.

     

Proliferative index activity in oral squamous cell carcinoma: indication for postoperative radiotherapy?

The predictive value of the Ki-67 labelling index and its relationship with radiosensitivity in oral squamous cell carcinoma (SCC) remains controversial. We sought to evaluate whether the expression of Ki-67 antigen found in SCC of the tongue and the floor of the mouth is an indication for postoperative radiotherapy (PORT). The first study group included 34 patients who were treated only with primary surgery, while the second group included 26 patients who underwent primary surgery combined with PORT. The correlation between Ki-67 expression and loco-regional recurrence, as well as the 5-year disease-specific survival, was assessed in the two groups. Cases of high-proliferative tumours showed a significantly higher risk of loco-regional recurrence (P = 0.018) and a poorer prognosis (P = 0.001) only in the 34 patients treated with surgery alone. In multivariate Cox regression analysis, high Ki-67 expression was an independent predictor of loco-regional recurrence (HR 5.42, P = 0.029) and disease-specific survival (HR 9.02, P = 0.004). The correlation between Ki-67 expression and the risk of loco-regional recurrence in SCC of the tongue and the floor of the mouth may be useful in the selection of patients at a higher risk of recurrence who would benefit from PORT, despite adequate margins of resection and early stage of the disease.     

Immunoexpression of proteins involved in cytoskeleton remodeling in benign odontogenic lesions

ObjectiveThe present study was designed to analyze the immunolocalization of proteins involved in cytoskeleton remodeling, such as moesin and Rho-A, in benign odontogenic lesions that present with expansive growth and invasive clinical behavior.Materials and methodsExpressions of moesin and Rho-A in odontogenic epithelium were evaluated by immunohistochemical analysis in 45 odontogenic lesions using monoclonal antibodies.ResultsOur results demonstrated strong membranous and cytoplasmic expressions of moesin in the epithelial cells in 66.7% and 44.4% of the odontogenic lesions, respectively. Furthermore, Rho-A expression in odontogenic epithelium was strong in the membrane and cytoplasm of 51.1% and 62.2% of the odontogenic lesions, respectively. A statistically significant correlation was found between the membranous and cytoplasmic expressions of moesin (p = 0.000) and those of Rho-A (p = 0.048) in odontogenic epithelial cells, while no statistically significant correlation was found between moesin and Rho-A expressions (p > 0.05).ConclusionsThe present study confirmed the strong expressions of moesin and Rho-A by odontogenic epithelial cells, suggesting their involvement in the development of benign odontogenic lesions. However, this study has failed to detect the connection between the moesin and Rho-A interaction in expansive growth and local invasiveness of these lesions.     

Bonding effectiveness and multi-interfacial characterization of two direct buildup resin core systems bonded to post-space dentin

Objectives

The aim of the present study was to evaluate the bonding effectiveness of two resin core buildup systems using conventional methods in the field of adhesive dentistry and a new non-destructive method.

Materials and methods

Twenty-four single-rooted human teeth were built up with dual-cure one-step self-etch adhesive and composite systems (SY1: Clearfil DC bond and Clearfil DC core automix, SY2: Clearfil bond SE one and Clearfil DC core automix one). The prepared samples were sectioned into approximately 1 × 1-mm-thick beams and subjected to micro-tensile bond strength (μTBS) testing (n = 24). The fractured beams after μTBS testing were analyzed by SEM and energy-dispersive X-ray (EDX) spectrometry. The three teeth filled with each resin core system were sectioned and embedded in epoxy resin to observe the dentin–bonding interface under TEM (n = 6). Moreover, three of each resin core-filled teeth without any processing were examined using μCT (n = 6).

Results

Two-way ANOVA revealed that the two factors “root region” (p < 0.001, F = 15.22) and “system” (SY1 < SY2; p < 0.001, F = 22.52) had a significant influence. The μTBS gradually decreased from the coronal side to the apical side of the root canal. Morphological evaluation revealed that SY2 was superior in terms of resin curing at the apical side. μCT non-destructive evaluation clearly revealed gap formation in SY1.

Conclusion

SY2, which included a new light-independent catalyst, showed better bonding effectiveness and adhesive interface to dentin compared to that of SY1.

Clinical relevance

The new catalyst, which is activated by contact with adhesive and resin composite, can be used for resin core buildup restorations.

     

Impact of combined CO2 laser irradiation and fluoride on enamel and dentin biofilm-induced mineral loss

Objectives

The caries-protective effects of CO₂ laser irradiation on dental enamel have been demonstrated using chemical demineralization models. We compared the effect of CO₂ laser irradiation, sodium fluoride, or both on biofilm-induced mineral loss (∆Z) and Streptococcus mutans adhesion to enamel and dentin in vitro.

Materials and methods

Ground, polished bovine enamel, and dentin samples were allocated to four groups (n = 12/group): no treatment (C); single 22,600-ppm fluoride (F) varnish (5 % NaF) application; single CO₂ laser treatment (L) with short pulses (5 μs/λ = 10.6 μm); and laser and subsequent fluoride treatment (LF). Samples were sterilized and submitted to an automated mono-species S. mutans biofilm model. Brain heart infusion plus 5 % sucrose medium was provided eight times daily, followed by rinses with artificial saliva. After 10 days, bacterial numbers in biofilms were enumerated as colony-forming units/ml (CFU/ml) (n = 7/group). ∆Z was assessed using transversal microradiography (n = 12/group). Univariate ANOVA with post hoc Tukey honestly-significant-difference test was used for statistical analysis.

Results

Bacterial numbers were significantly higher on dentin than enamel (p < 0.01/ANOVA). On dentin, LF yielded significantly lower CFUs than other groups (p = 0.03/Tukey), while no differences between groups were found for enamel. The lowest ∆Z in enamel was observed for L (mean/SD 2036/1353 vol%×μm), which was not only significantly lower than C (9642/2452 vol%×μm) and F (7713/1489 vol%×μm) (p < 0.05) but also not significantly different from LF (3135/2628 vol%×μm) (p > 0.05). In dentin, only LF (163/227) significantly reduced ∆Z (p < 0.05).

Conclusion/clinical relevance

CO₂ laser irradiation did not increase adhesion of S. mutans in vitro. Laser treatment alone protected enamel against biofilm-induced demineralization, while a combined laser-fluoride application was required to protect dentin.

     

Modified tricalcium silicate cement formulations with added zirconium oxide

Objectives

This study aims to investigate the effect of modifying tricalcium silicate (TCS) cements on three key properties by adding ZrO₂.

Materials and methods

TCS powders were prepared by adding ZrO₂ at six different concentrations. The powders were mixed with 1 M CaCl₂ solution at a 3:1 weight ratio. Biodentine (contains 5 wt.% ZrO₂) served as control. To evaluate the potential effect on mechanical properties, the mini-fracture toughness (mini-FT) was measured. Regarding bioactivity, Ca release was assessed using ICP-AES. The component distribution within the cement matrix was evaluated by Feg-SEM/EPMA. Cytotoxicity was assessed using an XTT assay.

Results

Adding ZrO₂ to TCS did not alter the mini-FT (p = 0.52), which remained in range of that of Biodentine (p = 0.31). Ca release from TSC cements was slightly lower than that from Biodentine at 1 day (p > 0.05). After 1 week, Ca release from TCS 30 and TCS 50 increased to a level that was significantly higher than that from Biodentine (p < 0.05). After 1 month, Ca release all decreased (p < 0.05), yet TCS 0 and TCS 50 released comparable amounts of Ca as at 1 day (p > 0.05). EPMA revealed a more even distribution of ZrO₂ within the TCS cements. Particles with an un-reacted core were surrounded by a hydration zone. The 24-, 48-, and 72-h extracts of TCS 50 were the least cytotoxic.

Conclusions

ZrO₂ can be added to TCS without affecting the mini-FT; Ca release was reduced initially, to reach a prolonged release thereafter; adding ZrO₂ made TCS cements more biocompatible.

Clinical relevance

TCS 50 is a promising cement formulation to serve as a biocompatible hydraulic calcium silicate cement.

     

Effect of primary correction of nasal septal deformity in complete unilateral cleft lip and palate on the craniofacial morphology

PurposeTo assess the long-term effect of primary correction of the nasal septum during lip repair in unilateral complete cleft lip and palate on the craniofacial morphology.Material, subjects, methodsThe study material consisted of 54 lateral cephalograms made at the ages 7–22, including 28 cephalograms of patients from a study group (aged 7–14 years) after a primary correction of the nasal septum during lip closure and 26 cephalograms of patients from a control group (aged 12–22 years) operated on without septal correction. All cephalograms have been analysed with regard to skeletal, dental and soft-tissue relationships. Data distribution has been checked using Shapiro–Wilk test (α = 0.05). Student t-test was used to compare values of normal distribution and for the latter – Mann–Whitney test.ResultsThe comparison of all cephalometric values between the study and control groups revealed a statistically significant (α = 0.05) difference only for H (p = 0.0267), 1+: NB angle (p = 0.0175) and 1+: NA (mm) (p = 0.0249). Each of the three cephalometric measurements mentioned were greater in the study than in the control group.ConclusionNo negative effect from the primary nasal septum correction on maxillary development could be found in the study group.