Publications

UNLABELLED: Endodontic failures are usually the result of technical errors compromising the proper endodontic procedures required to control and prevent periradicular infections. Among these errors, the extrusion of materials through the apical foramen has been associated with periapical inflammation, postoperative pain, tissue necrosis, delayed periapical healing and long-term failure.

AIM: To compare the debris extruded through the apical foramen when different glide path files are used prior to endodontic instrumentation with the WaveOne Gold Primary file.

MATERIALS AND METHOD: Twenty-four mesial roots of extracted human mandibular first molars were divided into three groups (n=8): C-Pilot hand file (CPH) #15/.02; R-Pilot (RPL); WaveOne Gold Glider (WGG). The roots were placed in Eppendorf tubes containing 1.5% agar gel and weighed before and after instrumentation to calculate the weight of debris and irrigant solution extruded. Apical extrusion of debris was compared using one-way analysis of variance. The Games-Howell test was used for multiple comparisons due to heteroscedasticity, with a significance level of 5%.

RESULTS: Debris extrusion was significantly lower with the WaveOne Gold Glider file than with the R-Pilot file, which in turn produced less extrusion than the C-Pilot file.

CONCLUSION: All glide path files caused apical extrusion, with the WaveOne Gold Glider causing the least.

UNLABELLED: There are multiple methods for determining Vertical Dimension of Occlusion (VDO), but most of them require scientific validation.

AIM: To study the correlation between mandibular cephalometric measurements and VDO in young Chilean adults with complete dentition and known inclusion criteria, by using modified Knebelman's technique.

MATERIALS AND METHOD: The study population consisted of 96 young Chilean adults aged 18 to 35 years. Inclusion criteria were complete natural dentition, bilateral molar support, skeletal class I or mild class II, presence of anterior coupling, and asymptomatic temporomandibular joints. Exclusion criteria were prior or ongoing orthodontic treatment, having undergone orthognathic or other facial surgery, poor oral habits (mouth breathing, or lingual, labial or object interposition), severe dental crowding (IOTN score > 2), too much beard and/or soft tissue under the chin. Anthropometric measurements were taken with a modified digital vernier caliper. Mandibular cephalometric measurements were taken with the QuickCeph 2000 software on digital lateral cephalometric x-rays. All anthropometric and cephalometric measurements were taken by one operator. Based on the mandibular cephalometric measurements with the highest correlation, a mathematical model was proposed to predict the VDO [VDO' = (XAEO-STF)*0.3 + (R3R4 dist.)0.5 + (Go-Ar dist.)- 0.3 + (Ar-Po Mand.Depth.)*0.4 - 8], whose predictive capacity will be tested.

RESULTS: The three cephalometric measurements with highest correlation with VDO were selected. The resulting predictive model correlated significantly with actual VDO (r= 0.77), in addition to having significant correlation values according to the Björk-Jarabak facial biotypes.

CONCLUSIONS: The proposed mathematical model demonstrated a strong correlation with the Vertical Dimension of Occlusion. It is a reliable method, uninfluenced by the patient's sex or biotype, and is useful for restoring the VDO within a physiological range close to its original state.

UNLABELLED: Facial asymmetries, often subtle, can indicate imbalances that go beyond aesthetic concerns.

AIM: This cross-sectional study analyzed molar bite force, occlusal contact distribution, and masseter and temporal muscle thickness in adult women with facial symmetry and slight non-pathological facial asymmetry, which generally goes unnoticed and is often considered a variation of normality.

MATERIALS AND METHOD: Forty-two women aged 18 to 30 were evaluated for slight non-pathological facial asymmetry using the VECTRA M3. Two groups were established: facial symmetry (n=21) and slight non-pathological facial asymmetry (n=21). Molar bite force was measured with a dynamometer. T-Scan was used to evaluate occlusal contact distribution. Masseter and temporal muscles thickness was assessed using ultrasound. Analyses used a 5% significance level (Student's t-test).

RESULTS: No significant difference was found in maximum molar bite force between the groups, though the slight asymmetry group showed lower force in clinical observation. No significant difference was observed in masseter and temporal muscle thickness during rest and maximum voluntary contraction, but clinically, the masseter was thicker than the temporal in both groups, being thicker in the slight non-pathological facial asymmetry group than in the facial symmetry group. Occlusal contact distribution did not differ significantly between groups, but clinically, the slight non-pathological facial asymmetry group showed less distribution in the occlusal contacts of the first permanent molars and more pronounced distribution in the left hemiarch compared to facial symmetry group.

CONCLUSION: Although no significant difference was observed between groups in this study, the numerical analysis of the results highlights the importance of evaluating the stomatognathic system in dental procedures, particularly with regard to non-pathological facial asymmetry.

UNLABELLED: Oropharyngeal candidiasis (OC) is common among people living with HIV (PLWH). Persistent colonization of oral epithelial surfaces serves as an ecological niche for opportunistic pathogens and is a significant predisposing factor for OC development in PLWH. Mucosal colonization can lead to biofilm formation, directly impacting oral epithelium.

AIM: To assess Candida albicans and Candida dubliniensis colonization in subgingival biofilms of people living with HIV (PLWH) and undergoing antiretroviral therapy (ART).

MATERIALS AND METHOD: A sample of 51 PLWH who were receiving ART was studied, focusing on dental and periodontal parameters. Subgingival biofilm and mucosa samples were collected, and Candida spp. were identified using molecular techniques.

RESULTS: Men (average age: 41.11 ± 8.63) predominated. The main cause of HIV was sexual transmission. Fungal-related opportunistic diseases were observed in 18 patients, and LT CD4 counts were evaluated. A total 255 samples were collected, including 204 from gingivoperiodontal sites and 51 from oral mucosa. Candida spp. was detected in 55% of patients, with particular distribution patterns. Positive Candida spp. presence correlated with clinical attachment level and HIV treatments. Microscopic identification revealed the presence of hyphae at the time of microbiological sample collection. Molecular identification confirmed 16 Candida albicans and 36 Candida dubliniensis isolates, challenging their diagnostic importance.

CONCLUSIONS: The presence of yeast hyphae/pseudohyphae in subgingival biofilms indicates their role in gingivo-periodontal disease dysbiosis. PLWH in this Argentine region face challenges including limited access to healthcare. The study underscores the need for early oral health intervention, emphasizing the diagnostic significance of Candida.

UNLABELLED: Rehabilitating teeth after root canal treatment often requires the use of glass fiber posts (GFPs) to retain the final restorations, so the choice of resin cement is critical for bond strength (BS) and treatment success.

AIM: The aim of this study was to evaluate the effect of different GFP systems on BS to intraradicular dentin using two dual-curing resin cement types.

MATERIALS AND METHOD: Thirty bovine incisors with wide canals were filled endodontically with gutta-percha and epoxy resin sealer. Initially, the canal filling was removed, and 4 mm of the apical seal was left intact. The teeth were divided into three groups according to the GFPs used: AP (anatomical posts - prefabricated GFP (Reforpost #2, Angelus®) relined with composite resin (Filtek Z350, 3M ESPE); SPLENDOR (Splendor SAP, Angelus®), and milled CAD/CAM (FiberCAD, Angelus®). Posts were fixed with conventional (RelyX Ultimate, 3M ESPE) or self-adhesive resin cement (RC) (RelyX U200, 3M ESPE), following the manufacturer's instructions. After 48 h, the roots were sectioned into thirds and subjected to pushout BS testing using a universal testing machine. BS data were analyzed using Wilcoxon and Mann- Whitney U tests. Failure modes were assessed with Fisher's Exact test (α=0.05).

RESULTS: In the apical and middle root sections, BS was similar in the AP and Splendor groups, both of which performed better than the milled CAD/CAM group (p≤0.05). In the cervical section, BS was significantly higher for the anatomical posts than for Splendor and milled CAD/CAM posts. Self-adhesive RC promoted statistically lower BS compared to conventional RC for the milled CAD/CAM post in the cervical and middle thirds (p≤0.05). Self-adhesive RC provided statistically higher bond strength than conventional RC for the anatomical post in the apical third (p≤0.05). No significant difference in failure modes was observed between resin cements and different root sections (p>0.05).

CONCLUSION: The BS of the GFP system was affected by resin cement type and root section, with composite resin-relined anatomically shaped posts generally performing better.

AIM: To evaluate the influence of spatulas on resin composite color stability, and characterize the surface of both the spatulas and the resin composites before and after manipulation.

MATERIALS AND METHOD: Discs (ø6 mm x 2 mm) of suprananofilled resin composite (Palfique LX5/Tokuyama) and nanohybrid resin (Empress Direct/Ivoclar Vivadent) were fabricated. They were divided into groups (n=10), and manipulated with different spatulas: non-manipulated (control), metal spatulas (Almore Millennium/ Golgran, Almore #3/ Quinelato, LM Arte Modella/ Quinelato), or plastic spatulas (Jon). Manipulation involved lightly pressing the spatula 50 times against the resin composite on waterproof paper. Color was analyzed at three time points: immediately, after finishing and polishing, and after 24-hour immersion in distilled water, with CIELab* parameters, ΔEab, ΔE00, and ΔWID. Spatulas and resins were submitted to micromorphological and energy-dispersive X-ray spectroscopic (EDS) analysis. Generalized linear models or Kruskal-Wallis and Dunn tests (α=5%) were applied.

RESULTS: Resin color changed after manipulation with a metal spatula, but there was no significant difference in ΔEab and ΔE00 for the resin composites according to the spatula (p>0.05). The suprananofilled resin varied more than the nanohybrid resin over time (p<0.05). Abrasive wear was observed on the spatulas after manipulating the resin composites, with greater wear for the spatulas used with suprananofilled resin. EDS showed different spatula and resin composite compositions.

CONCLUSIONS: Metal spatulas influenced resin composite color stability, with greater color change for suprananofilled resin. The spatulas exhibited abrasive wear, attributable to the difference in hardness between the spatulas and the resin composites.