Temperature Changes In Pulp Chamber Research Articles

A comparative in vitro analysis of various temporization materials with respect to pulp chamber temperature changes during polymerization.

(1) To compare the temperature rise in the pulp chamber with different resin materials used for making provisional fixed partial dentures in anterior and posterior region while using Polyvinylsiloxane impression materials as matrix. (2) To identify a superior provisionalization material based on the amount of heat dissipated suitable for anterior and posterior provisional fixed partial denture fabrication. Temporary crowns and bridges are integral to Fixed Prosthodontics. It has been observed that conventional fixed prosthesis temporisation materials release heat due to the exothermic polymerisation reaction. When such a provisional material is directly let to set on a vital tooth, the heat transfer causes irreversible changes in the pulp tissue depending of the degree of change. Hence, this study observes amount of heat generation in various materials during temporisation procedure, by simulating similar conditions. Two Models were fabricated, one simulating missing lateral incisor (Model A) and another simulating missing first molar (Model B). Intact maxillary central incisors and canine for Model A and intact mandibular Second Premolar and Second Molar were selected to act as abutments. These abutment teeth were fitted with the tip of a K-type Thermocouple inside their pulp chambers and these were connected to a digital thermometer. Five temporisation materials were chosen for fabrication of temporary crowns through Direct technique. (1) polymethy methacrylate (Self Cure acrylic), (2) bisacryl composite (Protemp 4), (3) visible light cure urethane dimethacrylate (Revotec LC), (4) barium glass and fumed silica infused methacrylate (Dentsply Integrity) and (5)nano-hybrid composite (VOCO Structur 3). Ten observations were made for each provisional material on each model. During each observation, temperature rise was recorded at 30s interval from the time of application, through the peak and till a decrease in temperature is observed. Polyvinyl siloxane was used as matrix for all except light cure resin, where polypropylene sheet was used. Anova test used for statistical. ANOVA test revealed that there was a significant difference in the temperature changes associated with the provisional restorative materials used. Among the five, polymethy methacrylate (self cure resin) showed the maximum rise in temperature, followed by bisacryl composite (Protemp 4), visible light cure urethane dimethacrylate (Revotec LC), barium glass and fumed silica infused methacrylate (Dentsply Integrity) and nano-hybrid composite (VOCO Structur 3). There was no comparable difference between Model A and B but an overall reduction of temperature rise was observed in model B. VOCO Structur 3 showed the least temperature rise in the pulp chamber, and overall temperature rise was less for model B which can be attributed to the residual dentin thickness.

Pulp chamber temperature changes and enamel surface analysis during orthodontic composite removal using 3 different burs in a repeatable approach: an experimental study.

During the debonding phase every clinician has to take care of preserving the enamel structure and tooth temperature. The objective of this study was to analyze in vitro the increase of the pulp chamber temperature and the wearing of enamel surface, during adhesive removal after debonding. Sixty extracted human teeth were selected. An orthodontic bracket was bonded on each tooth and after bracket removal, intraoral scanner pictures were used to evaluate ARI for each tooth. Three different burs were tested: tungsten-carbide multiple blades, arkansas stone and ceramic bur. A mechanical arm controlled by a dedicated software was used to reproduce a repeatable act of composite removal. To analyze in vitro the pulp chamber temperature during the composite removal procedure, teeth were treated endodontically placing a thermocouple through the root canal from the apex. A software registered temperature changes in a continuous manner. The enamel surface of every tooth was tested after the removal of composite with an optical stereoscopic microscope. An association existed between maximum internal pulp chamber temperature variation and irrigation (P<0.0001) and between maximum internal pulp chamber temperature variation and bur type (P=0.0133), with a significantly lower temperature increase produced by the arkansas bur. A significant difference among groups was detected for ESI and EDI assessment (P=0.002, P=0.010). Considering the initial setup, temperature variation analysis showed more conservative results using the arkansas burs with irrigation. ESI and EDI indexes showed significant enamel surface damage using tungsten-carbide burs.

Pulp chamber temperature changes during orthodontic bonding – an in vitro study

Abstract Aim Using a thermal camera, the aim of the study was to determine pulp chamber temperature changes during orthodontic bonding produced as a result of variations in curing light sources, different curing distances and bracket types. Methods One hundred sixty maxillary premolar teeth were sectioned into two halves and embedded into acrylic moulds. Four curing light sources were used which further divided the overall sample into Halogen, light emitting diode (LED), powered LED, and high-power LED groups. Additional subgroups were created according to the applied curing distances (5 mm, 10 mm) and different bracket types (metallic or ceramic). A standardised bonding procedure was performed and pulp chamber temperature changes were evaluated using a thermal camera. Statistical analysis was performed using a three-way ANOVA. Results The Halogen light curing group revealed a significantly higher temperature rise in the pulp chamber compared to the other groups. A shorter curing distance produced increases in pulpal temperature. There was no significant effect as a result of the bracket type. Conclusions None of the curing light sources exceeded the critical value for pulp chamber temperature rise. The primary desirable outcome was the lowest temperature increase noted with the high-power LED unit. The secondary outcome related to the different brackets revealed no difference relative to pulp chamber temperature change. From a clinical perspective, high-power LED units could be safely used.

The effect of laser-activated bleaching with 445 nm and 970 nm diode lasers on pulp chamber temperature rise: an in vitro study

The aim of this study was to determine the pulp chamber temperature changes during bleaching procedures with irradiation from 445 nm and 970 nm diode lasers at different powers. A total of 120 human maxillary central incisors were used for this study. Diode lasers at two different wavelengths were irradiated in this evaluation: 970 nm at 1.5 W of power, 970 nm at 2 W, 445 nm at 1 W and 445 nm at 1.5 W. A thermometer was inserted into the pulp chamber and the temperature increase after bleaching was recorded. The results indicated that there was not a significant difference between the groups at the same wavelengths (P > 0.05). However, there was a significant difference between groups at different wavelengths (P < 0.05). The highest recorded pulp temperature increase was for the 970 nm diode laser with 2 W of power (2.0 0.5), and the lowest pulp temperature rise was 0.1 0.2 for the 445 nm diode laser with 1 W of power. According to the results of this study it can be concluded that the temperature elevation after bleaching with the diode laser at the wavelengths 970 nm and 445 nm is in the safe range, and both wavelengths with the parameters applied in this study can be used as prudent in-office bleaching techniques.

Pulp chamber temperature changes during orthodontic bonding – an in vitro study

Pulp chamber temperature changes during orthodontic bonding – an in vitro study

Impact of the Enamel Cleaning Procedure during Debonding on Endodontium Temperature: In Vitro Tests

Interference with live tooth tissue during dental treatment affects the temperature within the pulp. The pulp is sensitive to temperature changes, which can cause its inflammation. The aim of this study was to analyze the dynamics of pulp chamber temperature changes in response to the enamel cleaning procedure after orthodontic treatment. In the presented in vitro studies, by using a thermal imaging camera, the change in the temperature of the vestibular wall of the pulp chamber of the incisors and premolars was assessed as a function of time under the influence of polishing the enamel with the silicone rubber and aluminum oxides used during the debonding procedure after completion of orthodontic treatment with fixed appliances. The relationship between dentin density and enamel from changing the chamber temperature was evaluated by using Micro computed tomography, microtomography (micro-CT). The maximum achieved tooth surface temperature during polishing was 52.34 °C without water cooling and 43.15 °C using water cooling. The time after which a safe pulp temperature of 40 °C was obtained without water cooling was 29.4 s, while the time with water cooling was 34.6 s. The correlation between the maximum and average temperature achieved and the density of the teeth was analyzed based on micro-CT scans. No correlation between enamel or dentin density and rise in temperature was found.

Temperature change in pulp chamber of primary teeth during curing of coloured compomers: an in vitro study using pulpal blood microcirculation model.

IntroductionAn increase in the temperature of the pulp chamber occurs during polymerisation of all types of light-curing resin-containing restorative materials, due to both the exothermic reaction of the material and the energy absorbed during the curing process. Increase in temperature of the pulp chamber of primary teeth during the curing process or the thermal conductivity properties of coloured compomers (CCs) have not yet been investigated in detail. The aim of the present study was to investigate the increase in pulpal temperature in primary teeth during curing of CCs.Materials and MethodsA Class-II cavity was prepared on the extracted primary mandibular second molar. Pulpal microcirculation of the tooth was performed using an experimental mechanism. The study included 15 groups and 10 experiments in each. Seven different CCs: pink, blue, gold, silver, orange, lemon, green, respectively from two different manufacturers (Groups 1–7: Twinky Star; VOCO, Cuxhaven, Germany. Groups 8–14: Nova Rainbow; IMICRYL, Konya, Turkey.) and a tooth-CC (Group 15: Dyract XP; DENTSPLY, Weybridge, UK.) were applied in prepared cavity. In all groups the compomers were light cured for 40 s. Intrapulpal temperature changes (Δt) in 20th and 40th second were recorded. In Group-15 the Δt values in 10th second were also recorded as per the manufacturer’s instructions. The Kruskal–Wallis test and the Mann–Whitney-U test were used for statistical analyses.ResultsAt the end of 40-s irradiation time, the orange, lemon and green colours of Nova Rainbow resulted in significantly lower Δt values than the same colours of Twinky Star (p = 0.0001), and silver, blue, lemon, green, orange, and pink CCs of Nova Rainbow and the blue and silver shades of Twinky Star demonstrated lower Δt values than the reported critical temperature increase (5.5 °C).ConclusionAn increase in the irradiation time consequently led to an increase in the intrapulpal temperature. Therefore, manufacturers should focus on production of new CCs with shorter polimerization time.

Effect of cooling water temperature on the temperature changes in pulp chamber and at handpiece head during high-speed tooth preparation

ObjectivesIt was the aim of this study to evaluate the effect of cooling water temperature on the temperature changes in the pulp chamber and at the handpiece head during high-speed tooth preparation using an electric handpiece.Materials and MethodsTwenty-eight intact human molars received a standardized occlusal preparation for 60 seconds using a diamond bur in an electric handpiece, and one of four treatments were applied that varied in the temperature of cooling water applied (control, with no cooling water, 10°C, 23°C, and 35°C). The temperature changes in the pulp chamber and at the handpiece head were recorded using K-type thermocouples connected to a digital thermometer.ResultsThe average temperature changes within the pulp chamber and at the handpiece head during preparation increased substantially when no cooling water was applied (6.8°C and 11.0°C, respectively), but decreased significantly when cooling water was added. The most substantial drop in temperature occurred with 10°C water (−16.3°C and −10.2ºC), but reductions were also seen at 23°C (−8.6°C and −4.9°C). With 35°C cooling water, temperatures increased slightly, but still remained lower than the no cooling water group (1.6°C and 6.7ºC).ConclusionsThe temperature changes in the pulp chamber and at the handpiece head were above harmful thresholds when tooth preparation was performed without cooling water. However, cooling water of all temperatures prevented harmful critical temperature changes even though water at 35°C raised temperatures slightly above baseline.

Evaluation of Time-Dependent Temperature Changes during Different Interdental Stripping Procedures by Thermal Imaging: An In Vitro Study.

To investigate the temperature changes in pulp chamber of incisor and canine teeth during different stripping procedures with thermal imaging. Intact and freshly extracted human permanent 40 maxillary lateral incisor, 40 mandibular canine and 40 mandibular incisor teeth were selected for this study. Diamond bur, tungsten carbide bur and perforated diamond-coated disc were used for interdental stripping in high and low speed handpieces by air and water cooling. Temperature changes and cooling time of the tooth groups were recorded by a thermal imaging system. Paired t test and one-way analysis of variance (ANOVA) tests were performed for intragroup and intergroup comparisons of temperature changes and cooling time values. Stripping procedures created a statistically significant temperature rise in all study groups (p < 0.05). For maxillary lateral incisors and mandibular incisors, the greatest temperature rise was calculated during stripping with tungsten bur and perforated disk under air cooling (p < 0.001), while no statistically significant difference was found between the temperature rise values of mandibular canine teeth during different stripping procedures (p = 0.053). The lowest temperature rise and cooling time values among all tooth groups were observed during stripping with diamond bur under water cooling and the longest cooling time values were detected during stripping with perforated disc under air cooling (maxillary incisor; p < 0.001, mandibular incisor; p < 0.05, mandibular canine; p < 0.05). For all tooth groups, stripping with diamond bur in a high speed handpiece under water cooling produced the lowest temperature rise in the pulp chamber and the shortest cooling time values among different stripping procedures.

Evaluation of Temperature Changes in the Pulpal Chamber of the Primary Tooth During Curing of Colored Compomers

Purpose: To investigate the temperature changes in the primary teeth pulp chambers during the curing of different colored compomers Methods: Five extracted primary mandibular second molars were prepared with class II cavities. Gold, blue, green, berry, and tooth (control group) colored compomers were tested in two steps (aproximal and occlusal). Measurement of pulp chamber temperature changes during curing was performed with a J type thermocouple. The data including differences between the highest and initial temperature values were recorded and analyzed by two-way ANOVA and Mann-Whitney U tests Results: There were statistically significant differences temperature changes in groups (p&amp;lt; 0.05). Gold colored compomer showed the highest temperature increase in both proximal and occlusal surfaces. Tooth colored compomer(A2) showed the lower temperature increase. The temperature increase in aproximal cavities was found to be higher than the temperature increase in occlusal cavities. Conclusions: Colored compomer can be an alternative restorative materials in superficial class I and II cavities in primary teeth. Dark coloured compomers should be used in deep cavities.

Effect of laser treatment of dentin hypersensitivity on pulp chamber temperature

Objective To compare the pulp chamber temperature changes of Nd:YAP laser, Nd:YAG laser and semiconductor laser with the same power during dentin hypersensitivity treatment, and to evaluate the safety of these three laser treatments for dentin hypersensitivity. Methods 50 intact third molars were collected to prepare the dentin hypersensitivity model. The samples were randomly divided into Nd:YAP laser group (n=15), Nd:YAG laser group (n=15), semiconductor laser group (n=15), and blank control group (n=5). Each experimental group was divided into three subgroups (n=5) of 0.9 W, 1.4 W, and 1.8 W according to the laser power. The experiments were conducted with the corresponding laser parameters and thermocouple thermometer was used to record the temperature changes in the pulp chamber. The control group does not do any processing. After laser irradiation, one sample was randomly taken from each group and the morphology of dentin tubules was observed by scanning electron microscopy. Results When different power lasers were used to irradiate the samples, the temperatures of the pulp chamber in each group were increased. Among them, the temperature rise of the pulp chamber was smallest in the Nd:YAP laser group, followed by the semiconductor laser group, and the temperature rise was highest in the Nd:YAG laser group, but it was still lower than 5.5 °C that could cause pulp necrosis. Scanning electron microscopy results showed that after irradiation with different power lasers, the diameters of most dentinal tubules in the Nd:YAG laser group and the semiconductor laser group were narrowed or even melted, and the effect was better than that of the Nd:YAP laser group. Conclusion The treatment using Nd:YAP laser, Nd:YAG laser and semiconductor laser for dentin hypersensitivity will increase the temperature of the pulp chamber. However, the temperature rise is less than 5.5 ℃ and that will not cause irreversible damage to the pulp tissue. Nd:YAG laser and semiconductor laser have better dentinal tubule blocking effect, which is more suitable for laser dentin desensitization treatment than Nd:YAP laser. Key words: Laser; Dentin hypersensitivity; Pulp chamber; Temperature; Dentinal tubule

Bulk-Fill Restorative Materials in Primary Tooth: An Intrapulpal Temperature Changes Study.

Objectives:It was aimed to investigate the temperature changes in primary teeth pulp chamber during the curing/setting of bulk-fill restorative materials with different nanoparticle contents.Methods:Twenty-five extracted, primary mandibular second molars were prepared as a Class II cavity. Five bulk-fill restorative materials consisting of Equia Fil (HVGIC), glass carbomer (GC) cement, Sonic Fill (SF), X-tra Fil (XF), and Quix Fil (QF) were tested. The measurement of the pulp chamber temperature changes (starting temperature 37°C) during setting/curing was performed with a J type thermocouple. The data, differences between highest and initial temperature values, were recorded and analyzed by one-way ANOVA.Results:The temperature changes in the pulp chamber were in EF (2.81°C), GC (7.92°C), SF (3.33°C), XF (3.43°C), and QF (3.02°C). There were statistically significant differences between temperature changes in groups (P < 0.05).Conclusion:The tested bulk-fill resin composites and high-viscosity glass ionomer cement do not increase the intrapulpal temperature in primary teeth during the curing/setting.

Pulpal Temperature Rise: Evaluation after Light Activation of Newer Pulp-Capping Materials and Resin Composite.

Background:To evaluate temperature changes in pulp chamber during light activation of newer pulp- capping materials and composite resin using light-emitting diode.Materials and Methods:A standardized Class I cavity was prepared in 80 extracted, intact, noncarious mandibular first molars, keeping remaining dentin thickness of 0.5 mm. The teeth were divided into four groups of 20 teeth each. Following this, apical third of the mesial root of each tooth was cut and a K type thermocouple attached to digital thermometer was inserted into pulp chamber from the sectioned mesial root. Whole assembly with teeth was suspended in water bath with constant temperature at 37°C. The previously divided teeth in four groups, were lined with Calcimol LC (Group A), Activa (Group B), TheraCal LC (Group C), and Ionoseal (Group D), followed by 3 increments of Filtek Z350 × T universal restorative. The temperature rise following light activation of pulp-capping material, bonding agent, and composite was noted.Results:The temperature rise in the pulp chamber after light activation of Activa was highest among all pulp-capping materials, followed by teeth lined with Calcimol LC, Ionoseal, and least in teeth with TheraCal LC.Conclusions:Temperature rise in the pulp chamber after light activation of newer pulp-capping materials and composite was below critical threshold for irreversible pulpal damage. Among all the pulp-capping materials, TheraCal LC showed lowest temperature rise in pulp chamber.

In Vitro Study of Temperature Changes in Pulp Chamber During Root Planing Procedure Using Er:YAG Laser.

To assess temperature changes at specified time intervals during Er:YAG laser scaling and root planing of surfaces with dental calculus. Fifteen single-rooted teeth with advanced periodontal disease were extracted and fixed in a cylinder thermostat filled with distilled water at constant temperature (35.5°C). A specially designed thermal probe (type K thermocouple) accurate to ±0.1°C over the range from 20°C to 80°C was fitted into the pulp chamber of tooth sample. Scaling and root planing of the mesial and distal root surfaces was performed using an Er:YAG laser (Lite Touch, Syneron Dental, Israel) with a wavelength of 2940 nm, provided with a chisel tip, and at the following settings: output energy 100 mJ and 50 Hz, duration of irradiation - 40 sec, the tip in contact mode oblique to the root surface at an angle of approximately 10-15 degrees and water spray level 5-6. The temperature inside the pulp chamber was measured every 10 sec. The temperature in the pulp chamber taken every 10 seconds and compared with the temperature of 35.5°C at baseline decreased by 1.6°C, 2.4°C, 2.5°C, and 2.5°C for the first, second, third and fourth measurement, respectively. These changes did not reach statistical significance. The Er:YAG laser does not increase the temperature inside the pulp chamber. The assessed changes do not depend on the duration of irradiation which was kept within 40 seconds. Therefore, this treatment modality causes no thermal damage to the pulp under the above defined conditions and can be considered safe.

KALSİYUM SİLİKA İÇERİKLİ PULPA KAPLAMA MATERYALİNİN IŞIK KAYNAĞININ ÜÇ FARKLI MODU İLE POLİMERİZASYONU ESNASINDA OLUŞAN ISI ARTIŞININ İNCELENMESİ

Pulp damage may occur because of the temperature rise during polymerization of light-cured dental materials. Aim: The purpose of this study was to evaluate three different curing modes of a light emitting diode (LED) on the temperature rise in the pulp chamber during polymerization of a light-cured resin-modified calcium silicate filled pulp-capping material. Material and Method: A straight-cut was made to the occlusal surface of an extracted molar ensuring 1 mm dentin thickness over the pulp. Pulpal circulation was simulated by water cycling through the pulp chamber with a defined flow pressure to simulate the clinical case. Temperature rise was measured during the light curing of capping material (Theracal, Bisco Inc.,USA). Three modes of light curing unit (Planmeca Lumion,Mectron,Italy) were used to polymerizate the material; fast (FP), slow rise (SRP) and soft (SP). Thermal changes were measured by a data-logger. The data were statistically analyzed by one-way ANOVA. Results: ANOVA test showed that pulp chamber temperature changes were influenced by the mode of light source. All groups showed significant differences between each other (P<0.05). The intrapulpal temperature changes induced by different modes were: (7.19±0.44°C) for FP, (6.62±0.34°C) for SRP, (6.10±0.37°C) for SP. Conclusion: Following conclusions were drawn; The intrapulpal temperature changes induced by various light modes were: FP, SRP and SP in descending order. All curing modes of light curing unit showed significant differences between each other. Light curing of the TheraCal with different polymerization modes of the same light unit resulted in more than 5.5°C increase in the pulp chamber

Effect of light-activated bleaching on pulp chamber temperature rise: An in vitro study

This study aimed to compare the pulp chamber temperature changes that occur with the use of different light sources during vital bleaching with and without application of bleaching agents. One hundred and forty-four mandibular incisor teeth were divided into four groups (n = 36) according to the use of halogen light, light-emitting diode, 3 W and 1.5 W diode laser. The teeth in the main groups were divided into three subgroups (n = 12). First subgroup had no bleaching gel application. By White and Whiteness HP were applied with a thickness of 2 mm to the other subgroups respectively. The labial surfaces of the teeth were irradiated with a total time of 20 s. Temperature changes in the pulp chamber were measured and analysed by using anova and Tukey test. The 3 W diode laser induced the highest pulp chamber temperature rise (P = 0.000). Bleaching gel application reduced the temperature changes in the diode laser groups (P < 0.05). Diode laser activation during vital bleaching induces pulp chamber temperature rise, which may cause thermal tissue damage.

In-vitro assessment of temperature rise in the pulp during orthodontic bonding

In this in-vitro study, we evaluated the temperature changes in the pulp chamber during bracket bonding using 4 different light sources. Eighty intact extracted maxillary central incisors were used. The teeth were divided into 4 groups of 20 teeth each. Brackets (Mini Twin, Dentaurum, Ispringen, Germany) were bonded with Transbond XT (3M Unitek, Monrovia, Calif) adhesive and light cured with low-intensity halogen light for 40 seconds, high-intensity halogen light for 40 seconds, light-emitting diode (LED) light for 20 seconds, and plasma arc light (PAC) for 6 seconds. Light curing was performed 5 mm from tooth surfaces. A J-type thermocouple wire was positioned in the center of the pulp chamber. The results were analyzed with analysis of variance (ANOVA) and the Tukey HSD test. ANOVA and the Tukey HSD test showed that pulp chamber temperature changes were influenced by the type of light source. All groups showed significant differences between each other (P <0.001). The intrapulpal temperature changes induced by different light sources were the following: high-intensity halogen (6.84 degrees C +/- 2.44 degrees C), low-intensity halogen (4.71 degrees C +/- 0.96 degrees C), LED (2.95 degrees C +/- 1.12 degrees C), and PAC (0.96 degrees C +/- 0.83 degrees C). High- and low-intensity halogen light induced significantly higher intrapulpal temperature changes than did the LED and PAC. Except for the high intensity halogen light, orthodontic bonding with light-curing units did not exceed the critical 5.5 degrees C rise in temperature reported to produce pulpal damage.

Temperature Response in the Pulpal Chamber of Primary Human Teeth Exposed to Nd:YAG Laser Using a Picosecond Pulsed Regime

This study was conducted to analyze temperature variation in the pulpal chamber using the (Nd:YAG) picosecond-pulsed laser to promote ablation in enamel and dentin of primary teeth. Several previous studies reported the temperature rise in pulpal chamber during laser irradiation. Since there are no reports about pulp chamber temperature changes during irradiation with picosecond-pulsed laser, the purpose of our investigation is to quantify the intrapulpal temperature changes following picosecond-pulsed Nd:YAG laser irradiation of enamel and dentin of primary teeth. In this study, we used 10 intact primary exfoliated teeth: five molars and five incisors. We used a commercial neodymium:- yttrium-aluminum-garnet continuous-wave (CW)-pumped Q-switched and mode-locked Nd:YAG laser, with varying power levels (200, 300, and 350 mW) operating with 100-psec pulsed duration. Typical plots show differences between heating and cooling of enamel and dentin of anterior and posterior teeth. Whereas for enamel the time evolution curves are dependent on power used for the investigated range (200-350 mW), for dentin the differences are not so evident. Observing temperature enhancement for each power, we were able to analyze operational conditions where temperature changes do not exceed 5.5 degrees C. Power-time-temperature (PTT) diagrams for clinical operations were determined based on varying power level and exposition time. Through the heating-cooling cycle, we could extract conventional heating and cooling times for enamel and dentin. We have shown that the Nd:YAG picosecond-pulsed laser is a safe tool for ablation of primary teeth in a broad range of operational parameters.

Temperature rise during orthodontic bonding with various light-curing units--an in vitro study.

The purpose of this in vitro study was to investigate the temperature changes in the pulp chamber during bracket bonding using three different light sources. Bracket bonding was performed on one lower first premolar and one lower central incisor at two different distances (surface and 10 mm). The measurements were taken with a J-type thermocouple wire, placed in the pulp chamber and connected to a data logger. Analysis of variance revealed that pulp chamber temperature changes were influenced by the light source, the tooth type, and the distance from the tip of the light guide to the bracket surface. Halogen induced significantly higher intrapulpal temperature changes than light-emitting diode and Xenon Plasma Arc (PAC) (P = .000). The temperature increase was significantly higher when the light-guide tip was positioned at the surface of the teeth than at the 10-mm distance with all light-curing units (P = .000). All light-curing units produced higher intrapulpal temperature increase in the mandibular incisor than in the premolar. Power PAC produced significantly higher heat changes in the incisor than in the premolar. Orthodontic bonding with different light-curing units did not exceed the critical 5.5 degrees C value for pulpal health.

Pulp chamber temperature changes during resin composite photo-activation

The aim of the present study was to verify if there is any difference in the pulp chamber temperature rise during the photo-activation of two resin composites with different viscosities. Eighteen extracted bovine incisors were divided into two groups (n=9) that were restored with two different resin composites – Filtek Z250 and Filtek Flow (3M/ESPE Dental Products, St Paul, MN 55144, USA). During the photo-activation, with a conventional halogen light curing unit (XL 2500, 3M/ESPE), a type-K thermocouple registered the temperature rise peak in the pulp chamber. The temperature rise data were submitted to Student-t test at 5% significance. The resin composite Filtek Flow shows statically higher mean temperature rise (p<0.05). We conclude that the resin composites with different viscosities produce different temperature changes during the photo-activation.