The surface integrity of gutta-percha cones is a crucial factor in the success of endodontic procedures. Disinfecting solutions play a pivotal role in sterilizing gutta-percha cones, but their influence on gutta-percha surface topography remains a subject of concern. This systematic review aimed to present a qualitative synthesis of available laboratory studies assessing the influence of disinfecting solutions on the surface topography of gutta-percha and offers insights into the implications for clinical practice. The present review followed PRISMA 2020 guidelines. An advanced database search was performed in PubMed, Google Scholar, Embase, Scopus, LILAC, non-indexed citations and reference lists of eligible studies in May 2024. Laboratory studies, in English language, were considered for inclusion. The quality (risk of bias) of the included studies was assessed using parameters for in vitro studies. A total of 28 studies were included in the qualitative synthesis. Based on the included in vitro studies, surface deposits and alterations in the physical properties of gutta-percha cones were observed after the disinfection protocol. A comprehensive review of the available literature indicates that the choice of disinfecting solution, its concentration, and immersion time significantly affect the surface topography of gutta-percha cones.

The purpose of this study was to evaluate whether intracanal irrigation method could affect the adhesion between intracanal dentin and root canal filling materials (Gutta-percha/AH 26 sealer and Resilon/Epiphany sealer).

Thirty extracted human incisor teeth were prepared. Canals were irrigated with three different irrigation methods as a final rinse and obturated with two different canal filling materials (G groups : Gutta-percha/AH 26 sealer, R groups : Resilon/Epiphany sealer) respectively.

Group G1, R1 - irrigated with 5.25% NaOCl

Thirty obturated roots were horizontally sliced and push-out bond strength test was performed in the universal testing machine. After test, the failure patterns of the specimens were observed using Image-analyzing microscope.

The results were as follows.

Gutta-percha/AH 26 sealer groups had significantly higher push-out bond strength compared with the Resilon/Epiphany sealer groups (p < 0.05).

The purpose of this study was to evaluate the thermal expansion characteristics of injectable thermoplasticized gutta-perchas and a Resilon. The materials investigated are Obtura gutta-percha, Diadent gutta-percha, E&Q Gutta-percha Bar and Epiphany (Resilon).

The temperature at the heating chamber orifice of an Obtura II syringe and the extruded gutta-percha from the tip of both 23- and 20-gauge needle was determined using a Digital thermometer. A cylindrical ceramic mold was fabricated for thermal expansion test, which was 27 mm long, with an internal bore diameter of 3 mm and an outer diameter of 10 mm. The mold was filled with each experimental material and barrel ends were closed with two ceramic plunger. The samples in ceramic molds were heated in a dilatometer over the temperature range from 25℃ to 75℃. From the change of specimen length as a function of temperature, the coefficients of thermal expansion were determined.

There was no statistical difference between four materials in the thermal expansion in the range from 35℃ to 55℃ (p > 0.05). However, Obtura Gutta-percha showed smaller thermal expansion than Diadent and Metadent ones from 35℃ to 75℃ (p < 0.05). The thermal expansion of Epiphany was similar to those of the other gutta-percha groups.

The purposes of this study were firstly to identify the microbial species on gutta-percha (GP) cones exposed at clinics using polymerase chain reaction, and secondly to evaluate the short-term sterilization effect of three chemical disinfectants. It also evaluated the alteration of surface texture and physical properties of GP cones after 5-min soaking into three chemical disinfectants. 150 GP cones from two endodontic departments were randomly selected for microbial detection using PCR assay with universal primer. After inoculation on the sterilized GP cones with the same microorganism identified by PCR assay, they were soaked in three chemical disinfectants: 5% NaOCl, 2% Chlorhexidine, and ChloraPrep for 1, 5, 10, and 30 minutes. The sterilization effect was evaluated by turbidity and subculture. The change of surface textures using a scanning electron microscope and the tensile strength and elongation rate of the GP cones were measured using an Instron 5500 (Canton). Statistical analysis was performed.

Four bacterial species were detected in 29 GP cones (19.4%), and all the species belonged to the genus Staphylococcus. All chemical disinfectants were effective in sterilization with just 1 minute soaking. On the SEM picture of NaOCl-soaked GP cone, a cluster of cuboidal crystals was seen on the cone surface. The tensile strength of NaOCl-soaked group was significantly higher than the other groups (p < 0.05). Also, all disinfectants significantly increased the elongation rate of GP cones compared to the fresh GP cone (p < 0.05). Present data demonstrate that three chemical disinfectants are useful for rapid sterilization of GP cone just before obturation.

To evaluate the ratio of gutta-percha area in the canal after canal obturation with Continuous Wave of Condensation Technique (CWCT) with varying depths of plugger penetration, forty root canals of extracted human teeth were prepared up to size 40 of 0.06 taper with ProFile®. Canals of three groups were filled with CWCT with System B™ (Analytic Tech., USA) and different plugger penetration depths of 3, 5, or 7 mm from the apex. Canals of one group were filled with lateral condensation technique as a control. The filled teeth were cross-sectioned at 1, 2, and 3 mm levels from the apical foramen. The ratio of gutta-percha area in the canal was analyzed using Auto®Cad 2000. Data were analyzed with one-way ANOVA and Duncan's multiple range test.

At all levels, higher gutta-percha area ratio was found with deeper plugger penetration depth in CWCT, and cold lateral condensation group showed higher ratio than group of plugger penetration to apical 7 mm in CWCT.

At apical 1 mm and 2 mm levels, group of plugger penetration to apical 3 mm showed significantly higher gutta-percha area ratio than those of apical 7 mm and lateral condensation (p < 0.05).

It is concluded therefore that, under the conditions of the present study, deeper plugger penetration depth results in more favorable and efficient obturation in CWCT.

The purpose of this study was to evaluate the obturation efficiency of a non-standardized gutta-percha cone in curved root canals prepared with 0.06 taper nickel-titanium instruments.

Sixty simulated curved root canals in clear resin blocks were prepared with crown-down technique using 0.06 taper rotary ProTaper™ and ProFile (Dentsply-Maillefer) until apical canal was size 30. Root canals were randomly divided into 4 groups of 15 blocks and obturated with cold-laterally compacted gutta-percha technique by using either a non-standardized size medium gutta-percha cone or an ISO-standardized size 30 one as a master cone. Gutta-percha area ratio were calculated at apical levels of 1, 3, and 5 mm using AutoCAD 2000 after cross-sectioning, and the data were analyzed with one-way and two-way ANOVAs and Duncan's multiple range test.

Non-standardized size medium cone groups showed significantly higher gutta-percha area ratio than standardized cone groups at all apical levels (p < 0.01).

Non-standardized cone groups used significantly less accessory cones than standardized cone groups (p < 0.01).

The purpose of this study was to quantify the amount of remaining gutta-percha/sealer on the walls of root canals when three types of nickel-titanium rotary instruments(Profile, ProTaper and K³) and a hand instrument(Hedstrom file) used to remove these materials.

The results of this study were as follows:

In the total time for gutta-percha removal, Profile group was the fastest and followed by K³, Protaper, Hedstrom file group.

These results showed that instrumentation using nickel-titanium rotary instrument groups was faster than that using hand instrument group. The effect of gutta-percha removal using Profile group was better than that using Protaper and K³ group in the nickel-titanium rotary instrument groups.

The aim of this study is to compare the adaptability of thermoplasticized injectable gutta-percha technique to the canal walls in ribbon-shaped canals.

Thirty resin models simulated ribbon-shape canals were instrumented to #40 using .06 taper Profile systems. Three groups of each 10 resin models were obturated by the lateral condensation technique(LC) and the two thermoplasticized injectable gutta-percha technique; Ultrafil Endoset+Obtura II(EO) and Ultrafil Firmset(UF), respectively.

After resin model were kept at room temperature for 4 days, they were resected horizontally with microtome at 1, 2, 3, 4 and 5mm levels from apex. At each levels, image of resected surface were taken using CCD camera under a stereomicroscope at ×40 magnification and stored. Ratio of the area of gutta-percha was obtained by calculating area of gutta-percha cone to the total area of canal using digitized image-analyzing program. The data were collected then analyzed statistically using One-way ANOVA.

The results were as follows.

1. At 1mm levels, there was no statistically significant difference in the mean ratio of gutta-percha among the groups.

2. At 2mm level, EO showed the highest mean ratio of gutta-percha (p<0.05) and there was no significant difference between LC and UF.

3. At 3, 4, 5mm levels, EO and UF had significantly greater mean ratio of gutta-percha than LC(p<0.05) and there was no significant difference between EO and UF.

In conclusion, the thermoplasticized injectable gutta-percha techniques demonstrated relatively favorable adaptability to canal walls than lateral condensation technique in ribbon-shaped canals except for 1mm level.