Clinical applications of calcium silicate-based materials: a narrative review

Calcium silicate-based materials are hydrophilic materials with biocompatibility and bioactivity properties. Despite many advantages, they might present some problems related to discolouration, setting time, manipulation and solubility depending on the composition of the product and the type of clinical application. Calcium silicate-based materials can be evaluated under two types according to their intended use: calcium silicate-based cements (CSCs) and calcium silicate-based sealers (CSSs). CSCs can be used in many endodontic procedures including perforation repair, resorption repair, apical barriers, guided endodontic repair, vital pulp treatment, endodontic surgery, root fractures and root canal filling as a core obturation material. CSSs are available for use with gutta-percha to obturate root canals using cold and warm techniques, including the sealer-based obturation technique. The purpose of this review is to evaluate the available literature on CSCs and CSSs and to provide up-to-date information and recommendations for their clinical applications.

The value of potential immunohistochemical biomarkers and clinicopathological findings in predicting response to neoadjuvant chemotherapy in breast cancer

OBJECTIVE

Following neoadjuvant chemotherapy (NAC) in breast cancer (BC), complete treatment response is achieved in some patients, while treatment response is limited in others. Predicting non-responder patients can prevent exposure to adverse effects associated with chemotherapeutic agents and delays in selecting other treatment modalities. In this study, we aimed at identifying predictive factors related to tumor regression in patients with BC who received NAC.

PATIENTS AND METHODS

This single-center cohort included 91 patients with BC who underwent surgery following NAC based on pretreatment tumor biopsy. According to BC molecular subtype, tumor regression grade (TRG) was determined using the Miller-Payne scoring system in patients who received standard NAC. Immunohistochemical stainings for VEGFR3 and CD44 were applied to needle core biopsies obtained prior to NAC in these patients.

RESULTS

Pathological complete response (pCR) was achieved in 20 patients (22%). In univariate analysis, high Ki-67 expression, ER negativity, and HER2 positivity were determined to be predictive factors of TRG (p < 0.05). In multivariate analysis, Ki-67 was the single independent predictor of TRG, with a 1.05-fold effect size. CD44 and VEGFR3 levels did not affect TRG or survival (p > 0.05). There was a significant difference in TRG according to molecular subtype of BC (p < 0.001). The treatment response was 5.5-fold higher in HER2-positive patients compared with HER2-negative patients.

CONCLUSIONS

pCR rates were significantly higher in TNBC, HER2, and luminal HER2+ subtypes when compared with luminal HER2- subtype. Ki-67 >25% and ER negativity had a favorable effect on TRG after NAC. CD44 and VEGFR3 were not effective in predicting treatment response.

Comparison of clinical features and the impact of reproductive factors on by age at diagnosis young and elderly breast cancer patients in the middle Anatolian region of Turkey

OBJECTIVE

Reproductive risk factors have been shown to influence breast cancer etiology for women of different origin worldwide; most studies in young/older patients have been limited to analyzing survival or tumor characteristics within their age group. This study aimed to compare the clinicopathological characteristics, treatment regimens, survival outcomes, and the impact of reproductive risk factors on young and elderly breast cancer patients.

PATIENTS AND METHODS

The data were collected retrospectively between October 2015 and March 2021, where 77 young patients (≤ 40 years) and 107 elderly patients (>65 years) were included out of a total of 567 patients undergoing treatment at Kayseri City Training and Research Hospital General Surgery Clinic, Turkey. Logistic regression analysis was performed to assess the impact of risk factors according to age.

RESULTS

Luminal-like tumors were in the majority in both age groups; there was no difference in diagnostic stages and survival between groups. The nulliparity ratio, total breastfeeding duration, number of biological children, first full-term pregnancy age, body mass index (BMI), and breast density distribution were significantly statistically different between groups. According to the multiple binary logistic regression analysis results for age, the most significant factors with risk effects were variables age of menarche OR= 3.36 (95% CI: 1.44-7.86) and child number OR= 2.58 (95% CI: 1.75-3.79), respectively.

CONCLUSIONS

The importance of looking at the impact of different risk factors on breast cancer risk lies in the potential to develop valid risk prediction models that can allow targeted screening and preventive interventions for high-risk women. By identifying more influential risk factors in different geographical profiles, risk-based screening, and targeted prevention efforts can be encouraged, and these factors can be included in risk prediction models.

In vitro fracture strength and patterns in root-filled teeth restored with different base materials

BACKGROUND

There is little research on the effects of an intermediate base on the fracture strength of root-filled teeth. This study compared the fracture strengths and patterns of root-filled teeth restored with intermediate bases of glass-ionomer cement (GIC), zinc polycarboxylate cement (ZPC), dual-cured resin composite (DCRC) and Biodentine^® under resin composite.

METHODS

Standardized cavities were prepared in 100 extracted human maxillary and mandibular premolars, and root canal treatment was performed. The teeth were stratified and randomly allocated to five groups (n = 20): (i) GIC; (ii) ZPC; (iii) DCRC; (iv) Biodentine; and (v) prepared but unrestored (control). The teeth were subjected to an oblique, ramped load until fracture. The fracture loads, level, mode and location were recorded.

RESULTS

Mean fracture strengths of all restored groups were not significantly different amongst the groups. There were significant overall effects on mean fracture strength for tooth type (P = 0.002) and buccolingual width of the crown (P = 0.001).

CONCLUSIONS

The four materials were appropriate intermediate bases. The laminate restorative technique promoted fracture strengths that are likely to withstand normal and maximum masticatory function. The base material can influence failure mode, which may have implications for the clinical presentation of fractures of root-filled teeth.