Influence of ozone application in the stepwise excavation of primary molars: a randomized clinical trial.

OBJECTIVES: The aim of this randomized, controlled, three-arm parallel-group, double-blinded clinical trial was to investigate the clinical and microbiological effects of the ozone application in stepwise excavation of primary molars. MATERIALS AND METHODS: This study was conducted in in vivo conditions with 105 lower primary molars that had deep caries lesions. The teeth were randomly divided into three groups: (I) control group, conventional stepwise excavation with no disinfectants; (II) CHX (positive control) group, 2% chlorhexidine digluconate; and (III) experimental group, ozone application. Dentine samples were collected at 4 different time points (T0, at the first appointment, after partial removal of carious dentin; T1, at the first appointment, after applying disinfection procedure; T2, at the second appointment - at the end of the 4-month period - immediately after the removal of the temporary restoration; T3, at the second appointment, after the final excavation) for the microbiological analysis of mutans streptococci and lactobacilli and the total number of colony-forming units. Clinical changes including dentin color, humidity, and consistency were recorded. Data were analyzed using the Mann-Whitney U test, Friedman test, and chi-squared test (p = 0.05). RESULTS: The dentin became harder and drier after 4 months in all the groups. There was a gradual reduction in the total number of microorganisms in all the three groups. Bacterial reduction was greater in the CHX group compared to the ozone group (p = 0.002) and was greater in the ozone group compared to the control group (p = 0.015) after 4 months (control, 78%; CHX, 93%; ozone, 82%). CONCLUSION: Stepwise excavation of primary teeth provided successful outcomes in all the groups. Moreover, CHX, due to its practicality and cost-effectiveness, can be effectively used with one- or two-step indirect pulp therapies. CLINICAL RELEVANCE: Usage of cavity disinfectants in the stepwise excavation procedure contributes to the reduction of bacterial population in the cavity, which may allow the avoidance of the second step of the indirect pulp therapy for primary teeth.

Effect of photon-initiated photoacoustic streaming, passive ultrasonic, and sonic irrigation techniques on dentinal tubule penetration of irrigation solution: a confocal microscopic study.

OBJECTIVES: The aim of this in vitro study was to evaluate the efficacy of different irrigation techniques including laser-activated irrigation using an erbium:yttrium-aluminum-garnet (Er:YAG) laser with a novel tip design (photon-induced photoacoustic streaming (PIPS)), Er:YAG laser with Preciso tip, sonic activation, and passive ultrasonic activation on the final irrigation solution penetration into dentinal tubules by using a laser scanning confocal microscope. MATERIAL AND METHODS: In this study, 65 extracted single-rooted human mandibular premolars were instrumented up to size 40 and randomly divided into 5 groups (n = 13) based on the activation technique of the final irrigation solution as follows: conventional irrigation (control group), sonic activation, passive ultrasonic activation, Er:YAG-PIPS tip activation, and Er:YAG-Preciso tip activation. In each group, 5 mL of 5% NaOCl labeled with fluorescent dye was used during the activation as the final irrigation solution. Specimens were sectioned at 2.5 and 8 mm from the apex and then examined under a confocal microscope to calculate the dentinal tubule penetration area. Data were analyzed using two-way analysis of variance (ANOVA) and Tukey's post hoc tests (P = 0.05). RESULTS: Both Er:YAG laser (Preciso/PIPS) activations exhibited a significantly higher penetration area than the other groups (P < 0.05). Additionally, passive ultrasonic activation had significantly higher penetration than the sonic activation group and the control group. Statistically significant differences were also found between each root canal third (coronal > middle > apical) (P < 0.001). CONCLUSIONS: The results from the present study support the use of Er:YAG laser activation (Preciso/PIPS) to improve the effectiveness of the final irrigation procedure by increasing the irrigant penetration area into the dentinal tubules. CLINICAL RELEVANCE: The activation of the irrigant and the creation of the streaming with the Er:YAG laser have a positive effect on the irrigant penetration.

Evaluation of the bond strength of root-end placed mineral trioxide aggregate and Biodentine in the absence/presence of blood contamination.

OBJECTIVE: Mineral trioxide aggregate (MTA) has been accepted as an appropriate root-end filling material in endodontic microsurgery because of setting ability in the wet environment. The aim of this study was to assess the bond strength of root-end placed MTA and Biodentine (Septodont, Saint Maur des Fossés, France) in the absence/presence of blood contamination. MATERIALS AND METHODS: Forty-eight single-rooted maxillary incisors were used. subsequent to root-end resection and apical preparation using ultrasonic retro-tips, the specimens were randomly separated into two groups according to the root-end filling materials: MTA (Cerkamed Medical Company, Stalowa, Poland) or Biodentine. The specimens were then separated into two subgroups according to storage condition (absence/presence of blood) (n = 12). After obtaining 2.0 ± 0.1 mm slices, push-out tests were performed. Each slice was examined under a stereomicroscope to evaluate the failure mode. The data were analyzed using two-way analysis of variance and Tukey's post hoc test for multiple comparisons. The failure modes were analyzed using the Chi-square test (P = 0.05). RESULTS: The bond strength was significantly affected by the presence of blood contamination and root-end filling material type (P < 0.001). Biodentine had better bond strength than MTA (P < 0.001). The most common failure type was adhesive failure. According to the Chi-square test, there were no statistically significant differences among the groups (P = 0.394). CONCLUSIONS: Biodentine had better bond strength values compared to MTA, and the bond strength of both MTA and Biodentine as root-end filling materials was negatively affected by the presence of blood.

Dentinal tubule penetration of AH Plus, iRoot SP, MTA fillapex, and guttaflow bioseal root canal sealers after different final irrigation procedures: A confocal microscopic study.

BACKGROUND AND OBJECTIVE: Varied physical and chemical characteristic of root canal sealers and different irrigant agitation systems can influence the depth of penetration. The aim of this in vitro study was to use a laser scanning confocal microscope in order to assess the dentinal tubules penetration of various sealers after the application of different final irrigation techniques. STUDY DESIGN/MATERIALS AND METHODS: A total of 156 single-rooted extracted mandibular premolars were prepared up to size 40 and randomly distributed into four groups according to the sealer type (n = 39): AH Plus, iRoot SP, MTA Fillapex, and GF Bioseal. Each group was randomly subdivided into three groups according to the final irrigation protocol (n = 13): conventional needle irrigation (CI), photon-induced-photoacoustic streaming activation (PIPS), and passive ultrasonic irrigation (PUI). After the final irrigation procedures, the root canals were obturated with single gutta-percha and labeled sealer mixed with 0.1% fluorescent rhodamine B isothiocyanate. Specimens were sectioned at 2, 5, and 8 mm from the apex, and all the sections were examined under confocal microscope to calculate the dentinal tubule penetration area. Data were analyzed using three-way analysis of variance and Tukey's post hoc tests (P = 0.05). RESULTS: iRoot SP exhibited a significantly higher penetration area than the other groups (P < 0.001), although there were no statistically significant differences between AH Plus, MTA Fillapex, and GF Bioseal (P > 0.05). Er:YAG laser activation with PIPS and PUI had significantly higher penetration than CI (P < 0.001). Statistically significant differences were also determined at each root canal third (coronal > middle > apical; P < 0.001). CONCLUSIONS: The dentinal tubule penetration area was significantly affected by the selection of root canal sealer, final irrigation procedure, and root canal third. Use of iRoot with PIPS tip or PUI seems advantageous in dentinal tubule penetration.

Multidisciplinary Management of Complicated Crown-Root Fracture of an Anterior Tooth Undergoing Apexification.

The purpose of this case report was to present the multidisciplinary management of a subgingival crown-root fracture of a patient undergoing apexification treatment. A 12-year-old male patient was referred to the pediatric dentistry clinic with an extensive tooth fracture of the right permanent maxillary lateral incisor. Clinical and radiographic examinations revealed the presence of a complicated crown-root fracture, which had elongated to the buccal subgingival area. The dental history disclosed that the apexification procedure had been started to be performed after his first trauma experience and he had neglected his appointment. The coronal fragment was gently extracted; endodontic treatment was performed; flap surgery was performed to make the fracture line visible. The coronal fragment was reattached to the root fragment with a dual-cure luting composite. A fiber post was stabilized and the access cavity of the tooth was restored with composite resin. At the end of the 24th month, the tooth was asymptomatic, functionally, esthetically acceptable and had no periapical pathology. It is important for the patients undergoing apexification treatment to keep their appointments because of the fracture risk. Restoration of the fractured tooth by preparing retention grooves and a bonding fiber-reinforced post are effective and necessary approaches for successful management.

Effect of PIPS technique at different power settings on irrigating solution extrusion.

The aim of this study was to determine the effect of photon-induced photoacoustic streaming (PIPS) technique at different power settings on extrusion of irrigating solution. Root canal preparation was performed up to a #30 file on 64 extracted single-rooted mandibular premolar teeth, which were then divided into four groups. Each group was irrigated with one of the following irrigation methods: (a) irrigation with conventional irrigation open-ended needles, (b) continuous ultrasonic irrigation, (c) 0.3 W PIPS, or (d) 0.9 W PIPS. Apical extrusion of irrigating solution was evaluated using a modified model. The net weight of the extruded irrigating solution was measured for each group, and the resulting data were analysed statistically using Kruskal-Wallis at a 95 % confidence level (P < 0.05). Although the 0.9 W PIPS group resulted in the largest quantity of irrigation solution, the ultrasonic group was the smallest. However, the difference between these groups was not statistically significant at the 95 % level of confidence (P > 0.05). PIPS at both 0.3 W and 0.9 W resulted similar solution extrusion to the conventional irrigation or ultrasonic irrigation.

The effect of photon-initiated photoacoustic streaming, ultrasonically and sonically irrigation techniques on the push-out bond strength of a resin sealer to the root dentin.

OBJECTIVES: The present study investigated the effects of various irrigation activation techniques, including laser-activated irrigation using a laser with a novel tip design (photon-induced photoacoustic streaming, PIPS) on the bond strength of an epoxy resin-based sealer to root dentin. MATERIALS AND METHODS: Seventy-two single-rooted human mandibular premolars were prepared using the rotary system to size 40 and randomly divided into four groups (n = 18) according to the final irrigation activation technique used as follows: conventional irrigation (CI), laser-activated irrigation with PIPS (LAI-PIPS), passive ultrasonic irrigation (PUI), and sonic irrigation (SI) with 5 mL of 17 % EDTA and 2.5 % NaOCl. The root canals were then obturated with gutta-percha and AH PlusJet sealer. A push-out test was used to measure the bond strength between the root canal dentin and the sealer. The data were analyzed using the two-way analysis of variance and least significant difference (LSD) post hoc tests (P = 0.05). RESULTS: The LAI-PIPS and PUI resulted in higher push-out values compared to CI and SI (P < 0.05). There were no statistically significant differences between CI and SI (P = 0.978) and between LAI-PIPS and PUI (P = 0.051). There was a statistically significant interaction between the final irrigant activation techniques used and root canal thirds (P < 0.05). A chi-square test revealed no significant differences in the failure mode within the groups (P > 0.05). CONCLUSIONS: The use of LAI-PIPS and PUI can provide higher bond strength of resin sealer to root dentin compared to CI and SI techniques. CLINICAL RELEVANCE: The activation of the irrigant and the creation of the streaming have a positive effect on the bond strength of the resin sealer to root dentin.