Introduction: Coronal microleakage may significantly reduce the prognosis of endodontic treatment. Temporary restorative materials have a crucial role in preventing the infection of root canals between and after endodontic treatment. This in vitro study was designed to evaluate the coronal microleakage of three Temporary restorative materials used in endodontics: Coltosol, Cavisol and Cina.Materials and Methods: Seventy-five human premolars and molars were selected for this in vitro study. Access cavities were prepared and amalgam placed on the orifices of canals; the occlusal surfaces were then reduced by 4mm for the Temporary restoration. The teeth were divided into three experimental groups of 23 teeth and two control groups of 3 teeth. The access cavities in each group were sealed using one of the test materials and thermal cycling was applied (5-55°C for 150 cycles). Surfaces were then covered with nail polish and wax; the teeth were immersed in 2% methylene blue dye for 7 days. The teeth were rinsed, dried, and sectioned mesiodistally and evaluated under a stereomicroscope for microleakage. Data was analyzed using Kruskal-Wallis and Mann U Whitney tests.Results: The lowest microleakage value was observed in Cavisol and Coltosol groups and the highest in Cina group (P<0.001). There was no statistical difference between Cavisol and Coltosol.Conclusion: Coltosol and Cavisol have appropriate sealing properties as Temporary restorations, but the sealing ability of Cina was questionable.

Background: This study aimed to compare the effect of four Temporary luting agents on preventing the coronal microleakage of teeth restored with custom cast post and core. Materials and Methods: In this in vitro original study, after removing 9 mm of gutta percha from root canals of 32 single-canaled premolars, the acrylic resin patterns of the post and core were fabricated. Patterns were cast with Ni-Cr metal alloy and then cemented with glass ionomer. Using self-curing acrylic resin, provisional restorations were made. Then, teeth were randomly allocated to four groups for each Temporary cement including zinc oxide eugenol (Temp Bond), zinc oxide noneugenol (Temp Bond NE), noneugenol resin-based Temporary luting agent (Temp Bond Clear), and noneugenol urethane methacrylate polymer-based Temporary luting agent (Dento temp). Teeth were subjected to thermocycling, immersed in silver nitrate for 6 h and then sectioned. The amount of dye penetration in the margin of provisional crown and into the coronal part of the root canals was measured using a stereomicroscope. Data were analyzed using the Kruskal-Wallis and Dunn tests with significance level of 0. 05. Results: All the luting agents showed some degree of microleakage (Group 1 showed the most microleakage). According to the pair comparison between the groups, Group 1 revealed a significant difference with others (P < 0. 05). Furthermore, Group 2 showed more microleakage as compared to Group 4 (P = 0. 037). Conclusion: Temp Bond showed the highest microleakage as compared to other luting agents. Furthermore, Temp Bond NE revealed a weaker sealability as compared to Dento temp.

INTRODUCTION: The purpose of this in vitro study was to evaluate the sealing ability of the readymade Temporary filling and hand mixed materials by assessing coronal microleakage.MATERIALS & METHODS: Standardized access cavities were prepared in 80 intact human permanent premolar teeth. They were divided randomly into four experimental groups (n=20). The teeth were restored using one of the Temporary materials including Cavisol, Litrak, Zinc phosphate cement, Zinconol (IRM). Thermocycling was applied on the specimens. Methylene blue dye was applied and penetration was evaluated under stereomicroscope. Grading of the microleakage pattern was from 1 to 3, with 3 providing the best seal. Results were analyzed using one-way ANOVA test (P<0.05).RESULTS: Microleakage of Cavisol and Litrak samples achieved grade 3; whereas zinc phosphate cement and Zinconol samples absorbed the dye into the bulk of the materials. Cavisol was found to exhibit the best seal amongst the four tested materials followed by Litrak, zinc phosphate cement, and Zinconol. There was a statistically significant difference in the microleakage scores obtained between the materials (P<0.01).CONCLUSION: Among the four materials tested, readymade Temporary filling provided the best sealing ability over hand-mixed. This study emphasizes the importance of correct placement and sufficient thickness of Temporary filling materials in endodontic access cavities to ensure a tight seal.

Objective: This study aimed to evaluate the influence of different internal taper angles in endocrown preparations on the marginal and internal adaptation of 3D-printed restorations. Methods: Three standardized mandibular first molar models were prepared with internal taper angles of 6°, 10°, and 22°. Each model was scanned 12 times, and endocrown restorations were digitally designed and fabricated with a 3D printer using Freeprint® Temp resin. All restorations were seated by a single operator, and the adjustment time and frequency were recorded. Adaptation was assessed using the replica technique, and marginal, axial, pulpal, and axio-pulpal line angle gaps were measured under a stereomicroscope. Data were analyzed using one-way ANOVA and Tukey’s post-hoc test at the significance level of P<0.05. Results: The pulpal gap was significantly larger in the 22° taper group compared to both the 6° (P<0.001) and 10° (P=0.001) groups. The 6° taper group exhibited significantly greater marginal misfit than the 10° (P=0.035) and 22° (P=0.021) groups. The axio-pulpal line angle misfit was significantly higher in the 22° taper group than in the 6° group (P=0.016). No significant difference was observed in axial misfit among the groups (P=0.169). Notably, the 22° taper group required significantly less adjustment time and fewer adjustment attempts than the other groups (P<0.05). Conclusions: All three taper angles yielded restorations with clinically acceptable adaptation. Increasing the internal taper from 6° to 22° improved marginal fit and reduced clinical chairside adjustments; however, it resulted in a deterioration of pulpal adaptation.

Background and Aim: Water sorption of provisional crown materials decreases their mechanical properties and longevity, depending on the material type. This study aimed to compare the water sorption of three provisional crown materials in vitro.    Materials and Methods: In this in vitro experimental study, 14 disc-shaped specimens measuring 1 x 15 mm were fabricated from Telio CAD polymethyl methacrylate (PMMA) computer-aided design-computer-aided manufacturing (CAD-CAM) block (Ivoclar Vivadent), self-cure PMMA acrylic resin (Tempron GC), and ProviTemp K acrylic-based composite resin (Provi Temp K). The specimens were randomly coded and their weight (with 0.0001 g accuracy) and volume (with 0.001 mm accuracy) were measured. The water sorption of the specimens was calculated after 7 and 30 days. One-way ANOVA was applied for data analysis (α=0.05).    Results: On day 7, the highest water sorption was noted in Bisco acrylic-based composite resin (mean: 22.84±5.04 µg/mm3) and the lowest water sorption was recorded in PMMA CAD-CAM block (mean: 14.22±3.23 µg/mm3) (P=0.023). At 30 days, the highest water sorption was recorded in Tempron GC self-cure acrylic resin (mean: 48.53±18.44 µg/mm3) and the lowest water sorption was noted in PMMA CAD-CAM block (mean: 40.24±5.33 µg/mm3) (P=0.002). Conclusion: The water sorption of Bisco acrylic-based composite resin and Tempron GC self-cure acrylic resin was very high in the short-term. However, after 30 days, the water sorption of Bisco acrylic-based composite resin and PMMA CAD-CAM block was the same.  It appears that all three tested materials can provide acceptable clinical performance for the fabrication of provisional restorations.

Objectives: This study aimed to compare the marginal fit of Temporary restorations fabricated by the conventional chairside method, 3D printing, and milling. Materials and Methods: In this in vitro, experimental study, 14 Temporary restorations were conventionally fabricated over an implant abutment and analog that had been mounted in a phantom model at the site of canine tooth, using autopolymerizing acrylic resin and putty index. In digital manufacturing, the original model was scanned, and the final restoration was designed. Fourteen Temporary restorations were milled out of polymethyl methacrylate (PMMA) blocks, and 14 others were printed by a 3D printer. Temporary crowns were placed on the abutment, and images were obtained from specific areas under a stereomicroscope at x100 magnification to measure the amount of marginal gap. Data were analyzed using one-way ANOVA and Tukey’ s test (α =0. 05). Results: The mean marginal gap values for the Temporary crowns in the 3D printing, milling, and chairside groups were 91. 40, 75. 28 and 51. 23 µ m, respectively. The crowns that were conventionally fabricated chairside exhibited the lowest marginal gap, and the difference in this respect was significant among the three groups (P<0. 05). Conclusion: Temporary crowns fabricated by the chairside method showed significantly smaller marginal gap; however, the marginal gap of all three groups was within the clinically acceptable range.

Immediate implant placement has some advantages, such as time-saving, optimal soft tissue architecture preservation, and patient acceptance. In this case, prior to implant placement, minimally guided bone regeneration was performed to augment the concavity on the apico-labial aspect of a fractured maxillary right lateral incisor. After eight months, the tooth was extracted, and an implant was immediately inserted, and a provisional composite-based crown was delivered in the same appointment. After four months, well molded mid-facial gingiva and interproximal papilla were obtained, and a final metalceramic crown was fabricated. . .

Introduction: Characteristics of light-curing units (LCU), including irradiation uniformity and adequate light intensity, emission spectrum, exposure duration, correct light-curing technique, and regular monitoring of the LCU, are important factors in the success of composite resin restorations. In addition, infection control methods for LCUs have drawn great attention in recent years to control infection.Search Strategy: An electronic search was carried out in PubMed and Science Direct databases from 1985 to 2016 using these key word Light-curing unit, dental restoration failures, composite resin restorations, and dental restoration repair.Conclusion: This article tries to draw attention to the importance of LCUs and discusses the relevant issues. Additionally, the consequences of delivering too little or too much light energy, the concerns over leakage from undercured resins, and the ocular hazards are discussed. Practical recommendations are provided to help clinicians improve their use of the LCU so that their patients can receive safe and potentially longer lasting resin restorations.