Separation of Oral Cooling and Warming Requires TRPM8.

Cooling sensations arise inside the mouth during ingestive and homeostasis behaviors. Oral presence of cooling temperature engages the cold and menthol receptor TRPM8 (transient receptor potential melastatin 8) on trigeminal afferents. Yet, how TRPM8 influences brain and behavioral responses to oral temperature is undefined. Here we used in vivo neurophysiology to record action potentials stimulated by cooling and warming of oral tissues from trigeminal nucleus caudalis neurons in female and male wild-type and TRPM8 gene deficient mice. Using these lines, we also measured orobehavioral licking responses to cool and warm water in a novel, temperature-controlled fluid choice test. Capture of antidromic electrophysiological responses to thalamic stimulation identified that wild-type central trigeminal neurons showed diverse responses to oral cooling. Some neurons displayed relatively strong excitation to cold <10°C (COLD neurons) while others responded to only a segment of mild cool temperatures below 30°C (COOL neurons). Notably, TRPM8 deficient mice retained COLD-type but lacked COOL cells. This deficit impaired population responses to mild cooling temperatures below 30°C and allowed warmth-like (≥35°C) neural activity to pervade the normally innocuous cool temperature range, predicting TRPM8 deficient mice would show anomalously similar orobehavioral responses to warm and cool temperatures. Accordingly, TRPM8 deficient mice avoided both warm (35°C) and mild cool (≤30°C) water and sought colder temperatures in fluid licking tests, whereas control mice avoided warm but were indifferent to mild cool and colder water. Results imply TRPM8 input separates cool from warm temperature sensing and suggest other thermoreceptors also participate in oral cooling sensation.

The tolerance of a keystone ecosystem engineer to extreme heat stress is hampered by microplastic leachates.

Plastic pollution and ongoing climatic changes exert considerable pressure on coastal ecosystems. Unravelling the combined effects of these two threats is essential to management and conservation actions to reduce the overall environmental risks. We assessed the capacity of a coastal ecosystem engineer, the blue mussel Mytilus edulis, to cope with various levels of aerial heat stress (20, 25, 30 and 35°C) after an exposure to substances leached from beached and virgin low-density polyethylene pellets. Our results revealed a significant interaction between temperature and plastic leachates on mussel survival rates. Specifically, microplastic leachates had no effect on mussel survival at 20, 25 and 30°C. In turn, mussel survival rates significantly decreased at 35°C, and this decrease was even more significant following an exposure to leachates from beached pellets; these pellets had a higher concentration of additives compared to the virgin ones, potentially causing a bioenergetic imbalance. Our results stress the importance of adopting integrated approaches combining the effects of multiple environmental threats on key marine species to understand and mitigate their potential synergistic effects on ecosystem dynamics and resilience in the face of the changing environment.

Post-operative pain in non-surgical root canal treatment after sealer-based obturation versus warm vertical compaction: A randomized clinical trial.

AIM: Post-operative pain may occur after non-surgical root canal treatment (NSRCT). The root filling technique and choice of sealer may be contributing factors. This randomized controlled clinical trial compared post-operative pain and analgesics intake after NSRCT using a sealer-based obturation technique (SBO) with single-cone gutta-percha and calcium silicate sealer (CSS) versus a warm-vertical compaction (WVC) technique with gutta-percha and a resin-based sealer (RBS). METHODOLOGY: This study was designed as a parallel-two arm, double-blind, randomized superiority clinical trial registered at www. CLINICALTRIALS: gov (NCT04753138). Patients referred for NSRCT fulfilling the inclusion criteria participated in this study. Pre-operative periapical radiographs and CBCT scans were taken and numerical rating scale (NRS) pain scores were recorded. Upon completion of canal instrumentation, participants were randomly allocated to either Group SBO: SBO with CSS or Group WVC: Warm-vertical compaction with RBS. Post-operative pain and analgesics intake were recorded at 1, 3 and 7 days after endodontic treatment completion. Non-parametric Mann-Whitney U and Friedman tests and a generalized estimating equation were used to assess differences in pain scores between the groups, within each treatment group at different time points and for correlations, respectively. RESULTS: The study included 195 participants (212 teeth). One participant declined to submit the NRS form. Therefore, 194 participants (211 teeth) were included in the final analysis (99.5% response rate). No statistically significant differences in post-operative pain or analgesic intake existed between the two groups at any time point (p > .05). Age, pre-operative pain, apical diagnosis and post-operative analgesic intake were significantly related to post-operative pain (p < .05). CONCLUSIONS: Sealer-based obturation technique with CSS was associated with similar post-operative pain levels and analgesics intake as WVC with RBS. Regarding post-operative pain, SBO with CSSs may be a suitable clinical alternative.

Effect of heat application on the physicochemical properties of new endodontic sealers: an in vitro and SEM study.

Understanding the properties of endodontic sealers is vital for treatment planning. Calcium silicate-based sealers are important in modern endodontics. This study investigates the effect of heat on the physicochemical properties of new calcium silicate sealers, addressing concerns raised by clinicians seeking to combine their benefits with the gutta-percha obturation technique. Five endodontic sealers (AH Plus Bioceramic®, Total Fill® BC®, One-fil® Bioceramic, K-Biocer, Any-seal®) were evaluated. Each sealer (n = 16/group) was either kept at 37 °C or subjected to heat at 60 or 200 °C for 30 s. ISO 6876-2012 standards were used to measure setting time, flow, film thickness, and dimensional changes over time. SEM and EDS were utilized for surface and chemical analysis. Data analysis employed IBM SPSS Statistics version 26 with a 5% significance level for two-sided tests. The sealers' setting times were shortened by heat, except for Total Fill® BC with extended setting time. All sealers had significantly longer setting times than manufacturer specifications. Film thickness increased with temperature, while flow values decreased. K-Biocer sealer showed the highest flow (16.89 ± 0.57 mm) at 200 °C, while Total Fill® sealer had the lowest (15.32 ± 0.62 mm). Shrinkage was significant at 60 °C and 200 °C, with greater shrinkage at 200 °C. Heat caused surface deformations in all sealers. The 200 °C groups exhibited more voids in AH Plus Bioceramic®, Any-seal®, and One-fil® sealers, and higher void area in Total Fill®, One-fil®, and K-Biocer sealers (p value < 0.001). EDX analysis confirmed heat-induced chemical and elemental changes in all tested sealers. Elevated temperature affects the physicochemical properties and structure of the tested endodontic sealers. The consideration of endodontic sealer compatibility is essential when warm gutta-percha obturation techniques are used.

Fish fauna and environmental factors in river estuaries of small and medium-sized rivers on islands significantly influenced by warm currents.

River estuaries are influenced by terrestrial and marine areas, and have a unique environment that is constantly fluctuating. They are also important habitats for biodiversity conservation. Tanegashima Island is significantly influenced by the Kuroshio Current. Although nearby Yakushima Island has been recognized as a World Natural Heritage site and information on many species has been collected, there is little information on species inhabiting the river estuaries of Tanegashima Island. In this study, the river estuarine ichthyofauna of 26 small and medium-sized rivers on Tanegashima Island was surveyed and a total of 2758 individuals of 29 species and one genus belonging to 15 families were collected. The fish fauna of the river estuaries of Tanegashima Island were classified into three groups, namely the river estuaries where coastal terraces are underdeveloped and drowned valleys are formed, the river group where the riverbed gradient at the mouth is high, and other river groups. Environmental factors selected as being important for ordination of fish fauna were the altitude of the headstreams at the watershed scale, the gradient of the river estuarine area, and the presence or absence of rapids in the estuary. The importance of the geohistorical factor of drowned valley formation, in addition to habitat and watershed scale environmental factors, as a factor on river estuarine fish fauna is an important finding for future conservation of local biota diversity.

[Sealing effect of GuttaFlow2 in curved root canals].

OBJECTIVE: To evaluate the sealing ability of GuttaFlow2 single cone obturation in curved root canals. METHODS: (1) Slight, moderate and severe curved 3D printed root canals were made. After instrumentation, these samples were randomly divided into 2 groups (n = 10) according to different root canal filling techniques: GuttaFlow2 single cone group (GF2) and AH-Plus warm vertical compation group (WVC). All the samples were sectioned at 2 mm to apex (the apical of the root), 4 mm, 6 mm to apex (the middle of the root) and 8 mm to apex (the coronal of the root). The filling void areas were observed by stereomicroscope, and the percentages of void areas in each section were calculated by ImageJ 1.52a. (2) Forty-eight roots of extracted adult molars were selected. After instrumentation, they were randomly divided into 2 groups (n = 8): GF2 group and WVC group. Before root canal filling, the sea-lers were mixed with Rhodamine B dye for visualization under confocal laser scanning microscope. All samples were sectioned at 2 mm to apex (the apical of the root), 5 mm to apex (the middle of the root) and 8 mm to apex(the coronal of the root). Then, the percentages of sealer penetration into dentinal tubules in each section were calculated. RESULTS: At the apical of the root, there were no obvious voids in slight, moderate and severe curved canals in the GF2 group and the WVC group. There was no significant difference between the two groups (P > 0.05). At the middle of the root, there was no significant difference in the percentages of void areas between the two filling methods, but at the coronal of the root, there were more voids in the slight curved root canal in the GF2 group than in the WVC group, and the difference was significant (P = 0.009). The percentages of sealer penetration into dentinal tubules of slight, moderate and severe curved root canals in the GF2 group were 36.10%, 55.80%, 65.08%, respectively. And they were all higher than those in the WVC group (15.78%, 20.70%, 15.61%), respectively, the difference between the two groups was significant (P = 0.001). At the middle of the root, the percentages of sealer penetration into dentinal tubules of slight and moderate curved root canals in GF2 group were also significantly higher than those in the WVC group (P = 0.001). At the coronal of the root, there was no significant difference between the two groups (P > 0.05). CONCLUSION: GuttaFlow2 filling technique has the same sealing effect on the root canal at the apical and middle of the root as the warm vertical technique, but has a better sealing effect on the dentin tubules, especially for severe curved root canal.

Marine plastics, circular economy, and artificial intelligence: A comprehensive review of challenges, solutions, and policies.

Global plastic production is rapidly increasing, resulting in significant amounts of plastic entering the marine environment. This makes marine litter one of the most critical environmental concerns. Determining the effects of this waste on marine animals, particularly endangered organisms, and the health of the oceans is now one of the top environmental priorities. This article reviews the sources of plastic production, its entry into the oceans and the food chain, the potential threat to aquatic animals and humans, the challenges of plastic waste in the oceans, the existing laws and regulations in this field, and strategies. Using conceptual models, this study looks at a circular economy framework for energy recovery from ocean plastic wastes. It does this by drawing on debates about AI-based systems for smart management. In the last sections of the present research, a novel soft sensor is designed for the prediction of accumulated ocean plastic waste based on social development features and the application of machine learning computations. Plus, the best scenario of ocean plastic waste management with a concentration on both energy consumption and greenhouse gas emissions is discussed using USEPA-WARM modeling. Finally, a circular economy concept and ocean plastic waste management policies are modeled based on the strategies of different countries. We deal with green chemistry and the replacement of plastics derived from fossil sources.

Wound Healing Following Palatoplasty Using Either Honey or Warm Saline Mouth Bath for Postoperative Wound Care: A Randomized-Controlled Study.

OBJECTIVE: To evaluate and compare the effect of honey or saline mouth bath for wound care on the rate of re-epithelisation of the lateral palatal defects and occurrence of early postoperative complications following palatoplasty. METHODOLOGY: This was a prospective randomized study on participants with non-syndromic cleft palate conducted at a tertiary health institution in Lagos, Nigeria. The test group received oral honey drops for post-operative care for an initial period of two weeks post-surgery, while the control group had regular oral toileting using a warm saline solution. The primary outcome was epithelisation of lateral palatal defect at 2- and 4-weeks post repair. Descriptive and comparative statistics were computed, and the p-value was set at <0.05. RESULTS: Fifty participants were recruited into the study, 24 in the Test group and 26 in the Control group. The frequency of occurrence of oronasal fistula in the Test group was 4.0% while in the Control group was 10.0%, however, this was not statistically significant. Complete epithelisation of the lateral palatal defect was clinically observed in 66.7% of the participants in the Test group at 2 weeks post-operation, while only 38.5% of participants in the Control group had clinically observed complete epithelisation at the same time point (ß = 1.70, p = .035, 95% CI 1.122-26.533). At four weeks, all wounds had epithelised irrespective of the study group. CONCLUSION: The application of honey appears to aid earlier epithelization of palatal surgical wounds following cleft palate repair and reduced the incidence of palatal fistula.

Long-term porosity and retreatability of oval-shaped canals obturated using two different methods with a novel tricalcium silicate sealer.

OBJECTIVE: To evaluate the percentage volume of voids and gaps in oval-shaped canals obturated using two different methods with a tricalcium silicate-based sealer after short- or long-term storage. The long-term effect of storage on the efficiency of removing filling material was also investigated. MATERIALS AND METHODS: Forty premolar teeth with oval-shaped canals were instrumented to Reciproc R25 and obturated using single cone obturation (SCO) or warm vertical compaction (WVC) techniques with gutta-percha and HiFlow sealer. The specimens were stored at 100% humidity and 37°C for 2 weeks or 6 months and scanned using micro-computed tomography. Initial retreatment was performed up to a Reciproc R40, and the operating time was recorded. The residual material in the canal received a supplementary procedure using XP-endo Finisher R (XPFR) files. After each retreatment procedure, the specimens were rescanned. RESULTS: The percentage volume of voids and gaps in the SCO group was higher than that of the WVC group at both 2 weeks and 6 months (P < 0.05). The percentage volume of the filling material removed after initial retreatment and XPFR cleaning was significantly higher in the 6-month group than in the 2-week groups (P < 0.05). The proportion of the residual material decreased significantly when XPFR files were used, compared to the initial retreatment group (P < 0.05) in both storage times. CONCLUSION: The efficiency of retreatment in the oval-shaped canal was closely related to the storage time rather than the filling technique using a tricalcium silicate sealer. The XPFR instrument proved effective in the removal of the remaining materials from the oval-shaped canal. CLINICAL RELEVANCE: Obturation of the oval-shaped canal with TSBS using the SCO technique in the coronal area needs to be optimized. The retreatment was less efficacious in freshly filled canals than aged filled canals.

The Impact of Atmospheric Parameters on the Dielectric Permittivity Values of SikaBlock®-M150 and Other Rigid Polyurethane Foams Measured with a Capacitive One-Side Access Sensor.

A shortage of research on the impact of atmospheric parameters on the measured dielectric permittivity values of rigid polyurethane (PU) foams was identified. Therefore, the impact of temperature, pressure, and relative humidity of air in the test room on the measured values of dielectric permittivity of rigid PU foams of different densities as well as monolithic polyurethane was investigated in a year-long experimental research study with a capacitive one-side access sensor. It was shown that relative humidity has the highest correlation with the dielectric permittivity values of rigid PU materials. The detected values of parameters were linked to the water vapour mass in ambient air and its correlation with permittivity of the investigated materials was determined. The warm-up drift and warm-up time of the spectrometer were estimated experimentally. A novel methodology was demonstrated to determine the true permittivity spectrum of rigid PU foams without any involvement of the environmental chamber, desiccators, or saturated salt/water solutions. A relative increase in the measured dielectric permittivity value was estimated numerically for the entire density range of rigid PU foams, i.e., 33-1280 kg/m3 (including monolithic PU).

Comparison of Fracture Resistance between Single-cone and Warm Vertical Compaction Technique Using Bio-C Sealer® in Mandibular Incisors: An In Vitro Study.

AIM: The aim of the study was to compare the fracture resistance of the single-cone technique with the warm vertical compaction technique (WVCT) in mandibular incisors using Bio-C sealer®, by applying a compressive force using a universal testing machine (UTM) (Instron 5943; Instron, Norwood, Massachusetts, USA). MATERIALS AND METHODS: Twenty-two mandibular incisors were selected and divided into two groups after applying the same shaping protocol. To assess the influence of the wave vertical compaction technique on the fracture resistance, the first group was obturated by a single-cone obturation technique (SCOT) (n = 12), and the second group was obturated with a WVCT (n = 10). Bio-C sealer® (Angelus, Hague Netherlands) was used in the two obturation techniques. Wax-coated roots were put in an acrylic mold and loaded to compressive strength fracture in a mechanical material testing machine (UTM) (Instron 5943; Instron, Norwood, Massachusetts, USA), with Bluehill 3 software (version 3.15.1343) recording the maximum load at fracture. Fracture loads were compared statistically, and data were examined with the Mann-Whitney U test with a level of significance set at p ≤0.05. RESULTS: No statistically significant difference was registered between the SCOT (264.97 ± 83.975 N) and WVCT (313.35 ± 89.149 N) concerning the endodontically treated mandibular incisors' fracture resistance (p = 0.159). CONCLUSION: Warm vertical compaction technique (WVCT) did not affect the fracture resistance of endodontically treated mandibular incisors when compared to SCOT canal preparation. CLINICAL SIGNIFICANCE: General practitioners and endodontists face challenges during root canal treatment such as cracks and root fractures. This article aims to guide experts in choosing between the single-cone and the continuous WVCT aiming for higher long-term quality of root canal filling.

Effect of heat application on the physical properties and chemical structure of calcium silicate-based sealers.

OBJECTIVE: To determine the effect of heat application on the setting and chemical properties of HiFlow BC Sealer and compare to other calcium silicate (CSBS) and epoxy resin-based root canal sealers. MATERIALS AND METHODS: AH Plus, BioRoot RCS (BioRoot), Endosequence BC (Endosequence), and HiFlow BC (HiFlow) sealers were placed at 37 °C or subjected to heat at 200 °C for 10 or 30 s, followed by incubation at 37 °C in a humidified incubator during experiments. Setting time, viscosity, and flow were assessed, and changes in chemical structure were evaluated using the Fourier-transform infrared spectroscopy (FTIR). Thermogravimetric analysis was also used to evaluate the weight change (%) of the sealers upon heating from room temperature to 37 °C or 200 °C at a rate of 20 °C/min. Data were analyzed using a two-way ANOVA with a Bonferroni post-hoc test (p = 0.05). RESULTS: Application of heat extended the setting time for Endosequence and HiFlow but resulted in a faster setting of AH Plus and BioRoot. The highest flow and lower viscosity were observed in HiFlow at high temperature (p < 0.05), whereas the lowest flow with the highest viscosity and greatest weight loss were observed in BioRoot after heat application (p < 0.05). FTIR spectra demonstrated no changes to functional groups after heat application, except for the strong H-O-H absorption peak corresponding to water in BioRoot. CONCLUSIONS: Endosequence and HiFlow showed similar chemical properties with a higher flow and lower viscosity in HiFlow after heat application. Heat application resulted in reduced flow, increased viscosity, and weight loss for BioRoot. The setting of AH Plus was fastened with heat, while its weight loss, viscosity, and flow characteristics were stable. CLINICAL RELEVANCE: HiFlow, Endosequence, and AH Plus can be all used with WVC obturation techniques. Heat application resulted in minor changes in their physical properties including setting time, flow, weight loss, and chemical properties, while BioRoot showed a significant amount of weight loss, increase in viscosity, and reduced flowability after heat application.

Efficiency of Using Different Greater Taper Gutta-Percha Cones in Continuous Warm Vertical Condensation: An Ex Vivo Study.

AIM: The aim of this ex vivo randomized study is to evaluate the efficiency of gutta-percha cones that match a nickel-titanium instrumentation system and nonmatching greater taper cones, when used with continuous warm vertical condensation technique. MATERIAL AND METHODS: Thirty-six straight canals were prepared using ProTaper Next files, and the apical third was obturated using either ProTaperNext cones (group A), ISO uniform greater taper cones (group B), or nonstandardized cones (group C). Cone adaptation time was quantified by the number of required modifications. Micro-computed tomography was used to measure voids and sealer percentage. RESULTS: There was no significant difference between the groups regarding void volume (p = 0.666), percentage (p = 0.379), and the number of modifications (p = 0.757). Sealer percentage, however, was significantly lower in group B when compared to group A (p = 0.0194). CONCLUSION: In straight canals, matching gutta-percha cones were not associated with significantly better obturation or saving time to fit the cone. CLINICAL SIGNIFICANCE: Using gutta-percha cones that do not match a nickel-titanium instrumentation system to obturate the straight canals with continuous warm vertical condensation technique is as efficient as using matching cones in terms of obturation quality and ease of cone fit.

Real-time chemical analysis of root filling materials with heating: guidelines for safe temperature levels.

AIM: To investigate the chemical changes affecting different types of gutta-percha and endodontic sealers during heating, and correlate changes with the heating capacity of different heat carriers. METHODOLOGY: The heating capacity of three endodontic heat carriers was evaluated using thermocouples to produce heat profiles. The devices were activated at different temperature set-ups, in continuous or cut-out modes. Chemical changes of six brands of gutta-percha and four types of sealers were assessed in real time during heating using micro-Raman spectroscopy equipped with a heating stage. Raman spectra of each tested material were averaged and compared at different temperature levels. The sealers were further assessed by Fourier transform infrared (FT-IR) spectroscopy. RESULTS: None of the tested heat carriers achieved the temperature levels that were set by the devices and recommended by the manufacturer. The use of continuous heating mode resulted in higher rises in temperature than the 4 s cut-out mode that reached 110 °C. The various brands of gutta-percha exhibited different chemical changes in response to heat. Some changes even occurred below temperature levels generated by the heating devices. All sealers revealed changes in their chemical composition upon heating. Changes in epoxy resin- and zinc oxide-eugenol-based sealers were detectable at 100 °C, with structural alterations beyond that temperature and irreversible changes after cooling. Water loss was irreversible in BioRoot, but its chemical structure was stable as well as for the TotalFill. CONCLUSIONS: The heating capacity of endodontic heat carriers needs to be standardized, so that the temperatures delivered by the tips are the same as that set on the dial. Practitioners should be aware of the actual temperatures generated by these devices, and the suitability of sealers to be used at the temperature levels achieved.

Physico-chemical investigation of endodontic sealers exposed to simulated intracanal heat application: epoxy resins and zinc oxide-eugenols.

AIM: To gain information in a laboratory setting about the effect of thermal treatment of epoxy resin-based and zinc oxide-eugenol-based sealers. METHODOLOGY: AH Plus and Pulp Canal Sealer (PCS) were exposed to thermal treatment at 37, 47, 57, 67, 77, 87 and 97 °C for 30 s. According to clinically relevant considerations, intracanal sealer temperature is likely not to exceed 60 °C during warm vertical root canal filling. Heat application is recommended for less than 30 s during continuous wave technique, but might exceed this threshold in complex cases. Furthermore, heat treatment at 97 °C was performed for 60 and 180 s to simulate inappropriate implementation of warm vertical filling techniques. Specimens were heated inside 2-mL plastic tubes in a thermo-controlled water bath until the temperatures were reached and kept at this temperature for the determined period of time. Afterwards, specimens were cooled to body temperature and physical properties (setting time, flow, film thickness according to ISO 6876) were assessed. Chemical properties (Fourier transformed infrared spectroscopy) were assessed after complete setting of the specimens in an incubator at 37 °C and 100% humidity. Statistical analysis of physical properties was performed using Kruskal-Wallis test (P = 0.05). RESULTS: The setting time of AH Plus and PCS decreased when temperature and duration of heat application increased. Whilst the setting time of AH Plus decreased from 622 min at 20 °C (for 30 s) to 381 min at 97 °C (for 180 s; P < 0.05), heat treatment of PCS at 97 °C for 180 s led to an immediate setting of the material. From 20 °C (for 30 s) to 97 °C (for 30 s), the setting time of PCS decreased from 80.1 to 41.0 h (P < 0.05). Film thickness and flow were not relevantly influenced by thermal treatment except for PCS at 97 °C for 180 s. FT-IR spectroscopy did not reveal any chemical changes of either sealer after thermal treatment. CONCLUSIONS: Thermal treatment simulating clinically relevant temperature levels and heating times did not lead to any substantial physical or chemical changes at all temperature levels when heating did not exceed 60 s. AH Plus and Pulp Canal Sealer can be considered suitable for warm root filling techniques.

Evaluation of effect of warm local anesthetics on pain perception during dental injections in children: a split-mouth randomized clinical trial.

OBJECTIVES: The present study evaluates the efficacy of warm local anesthetic (37 °C) administration and injections of local anesthetics at room temperature (21 °C) in reducing pain during injections in children undergoing dental procedures. MATERIALS AND METHODS: Enrolled for this split-mouth randomized clinical study were 100 children aged 5-8 years. Within the random crossover design selected for the study, each patient was randomly assigned to receive either a body or room temperature local anesthesia in the first session and the other local anesthesia on the second session. During the injection, the Wong-Baker Faces Pain Rating Scale was used as a subjective measure of discomfort, and heart rate as an objective measure. The Face, Legs, Arms, Cry, and Consolability (FLACC) scale was used to record the child's pain, based on the perception of the dental assistant. The data were analyzed using a Wilcoxon sign rank test and a paired t test. RESULTS: Based on the score of the Wong-Baker Faces Pain Rating Scale, the FLACC scale, and heart rate, the sensation of pain during dental injection in both girls and boys is statistically significantly lower at body temperature than at room temperature (p < 0.05). CONCLUSIONS: It was determined that the application of local anesthetic at body temperature reduces dental injection pain significantly when compared with local anesthetics administered at room temperature. CLINICAL RELEVANCE: The successful management of dental injection pain is an important issue during dental procedures in children. Accordingly, warming the local anesthesia prior to use in children can be recommended to clinicians.

Comparison of warm vertical compaction and cold lateral condensation of α, ß gutta-percha and resilon on apically extruded debris during retreatment.

BACKGROUND: This study was performed to evaluate the amount of apically extruded debris removed from a root canal filled with cold lateral condensation (CLC), and warm vertical compaction (WVC) techniques, using b or a phase gutta-percha with AH-Plus (Dentsply DeTrey, Konstanz, Germany) or Resilon (Resilon Research LLC, Madison, WI) with RealSeal SE (SybronEndo, Amersfoort, The Netherlands). MATERIALS AND METHODS: About 100 human incisor teeth were prepared with a #25.06 NiTi rotary system and divided into five groups according to the filling material used: Group 1: CLC (gutta-percha, AH-Plus); Group 2: WVC (b phase gutta-percha, AH-Plus); Group 3: WVC (a phase gutta-percha, AH-Plus); Group 4: CLC (Resilon, RealSeal SE); and Group 5: WVC (Resilon, RealSeal SE). Extruded debris during the retreatment procedure was collected in preweighed Eppendorf tubes. The times required for retreatment were recorded. RESULTS: The amount of debris extrusion was significantly greater with WVC than CLC in the gutta-percha and Resilon groups (P < 0.001). Using a phase gutta-percha resulted in significantly more debris extrusion than b phase gutta-percha (P < 0.001). In the WVC groups, Resilon caused significantly more debris extrusion than gutta-percha (P < 0.05). Retreatment was faster for CLC than WVC (P < 0.05). CONCLUSIONS: In the retreatment procedure, the amount of apically extruded debris and retreatment duration were dependent on the type of obturation material and technique used.

Can the Use of a Warm-Air Stream for Solvent Evaporation Lead to a Dangerous Temperature Increase During Dentin Hybridization?

PURPOSE: To analyze the effect of a warm-air stream for solvent evaporation on the temperature rise in the pulp chamber during dentin hybridization. MATERIALS AND METHODS: Dentin disks with thicknesses of 0.5, 1.0 and 1.5 mm were obtained from extracted human molars. A model tooth was set up with the dentin disks between a molar with an exposed pulp chamber and a crown with an occlusal preparation. A K-type thermocouple connected to a digital thermometer was placed in the molar root until it entered the pulp chamber and made contact with the dentin disks. After 10 s of adhesive application, solvent evaporation was performed for 10, 20, 30, and 40 s and the increase in temperature was monitored for 200 s after the warm-air stream began. RESULTS: The temperature increase was significantly influenced by the thickness of the dentin disks (0.5 mm = 1.0 mm > 1.5 mm). With respect to the duration of the warm-air stream, the temperature increase was as follows: 10 s < 20 s < 30 s < 40 s (p < 0.05). The highest temperature was found after 40 s with dentin disks that were 0.5 mm (16.6°C) and 1.0 mm (15.8°C) thick, whereas the lowest temperature increase occurred after 10 s with a dentin disk that was 1.5 mm thick (4.1°C) (p < 0.05). CONCLUSION: The temperature in the pulp chamber was strongly influenced by the dentin thickness and the duration of the warm-air stream. Thinner dentin and a longer duration of the warm-air stream both lead to a greater temperature increase in the pulp chamber.

Micro-CT evaluation of voids using two root filling techniques in the placement of MTA in mesial root canals of Vertucci type II configuration.

OBJECTIVE: The present study aims to compare two mineral trioxide aggregate (MTA) placement techniques, manual compaction and ultrasonic activation of manually compacted MTA, with warm vertical compaction (WVC) for orthograde obturation of mesial root canals of mandibular first molars showing Vertucci type II root canal configuration. MATERIALS AND METHODS: Thirty roots were selected according to their micro-CT scanned images. Root canals were chemomechanically prepared using Reciproc R25 and NaOCl using EndoVac. The specimens were divided into three groups according to the root canal filling technique, as manual compaction of MTA, ultrasonic activation of manually compacted MTA and WVC using gutta-percha and AH Plus (Denstply Sirona, Ballaigues, Switzerland). Percentages of voids located in apical 3 mm and remaining coronal half until the level where separate root canals re-join within filling were calculated. Data were analyzed using the Kruskal-Wallis and Dunn's tests, and significance was set at 5%. RESULTS: No significant difference was found among the filling techniques regarding the percentage volume of voids at apical 3 mm (P > 0.05). At the coronal half of the isthmus, WVC produced significantly less percentage volume of voids than manual compaction of MTA (P < 0.05) and similar to ultrasonic activation group did (P > 0.05). There was no significant difference between two MTA placement techniques at the coronal half of the isthmus (P > 0.05). CONCLUSIONS: No filling technique produced void-free fillings. The percentage of void volume was similar among groups at apical 3 mm but was different at the coronal half of the isthmus. CLINICAL RELEVANCE: Warm vertical compaction and ultrasonically activated MTA fillings revealed similar quality at the isthmus area, which was superior to manually compacted MTA.

Self-retaining barbed suture reduces warm ischemia time during laparoscopic partial nephrectomy.

OBJECTIVE: To evaluate the efficacy and safety of self-retaining barbed suture in renorrhaphy during laparoscopic partial nephrectomy by comparing surgical outcomes in a prospective randomized manner. MATERIAL AND METHODS: From July 2014 to July 2015, a total of 60 patients with T1 renal tumor were randomized into two equal groups: self-retaining barbed suture (SRBS) and conventional absorbable polyglactin suture (non-SRBS group). All patients were treated by retroperitoneal laparoscopic partial nephrectomy. One surgeon with high volume experience performed all procedures. The patient demographics and perioperative outcomes were compared. RESULTS: The patient demographics and tumor characteristics were comparable. The mean tumor size and R.E.N.A.L. scores were comparable between the two groups. LPN was successfully accomplished in all patients without open conversion. The warm ischemia and renorrhaphy times were significantly shorter in the SRBS group (18.8 ± 8.2 vs. 22.9 ± 7.3 min, P = .04; 10.4 ± 3.7 vs. 13.8 ± 5.6 min, P = .01). The minor complication rate was 13.3% vs. 10.0%, which was comparable. No major complication occurred. CONCLUSIONS: The randomized controlled trial demonstrates that SRBS for renorrhaphy during retroperitoneal laparoscopic partial nephrectomy is safe and efficient. Application of barbed suture simplifies the parenchymal repair procedure and reduces warm ischemia time in comparison with conventional suture.