Abstract
Introduction
This ex vivo study aimed to evaluate the shaping abilities and preservation of dentin with traditional
and modern instruments after using sizes 25 and 40 in oval canals of mandibular incisors
with conservative access.
Method
Thirty mandibular incisors with single straight oval canals were selected and assigned
into 2 groups (n = 15) according to the instrument system used during preparation, Slim Shaper (SS)
plus Apical Shaper (AS) and Protaper Gold (PG). The samples were subjected to micro-computed
tomography before and after preparation with sizes 25 and 40. The shaping parameters
evaluated included canal volume and surface area, amount of unprepared root canal
walls, and reduction in pericervical dentin.
Results
Canal volume and surface area were significantly increased after enlargement with
each instrument size (P < .01). The percentage of unprepared areas showed a significant intragroup decrease
after using PG F2 and F4 or SS 3 and AS (P < .05). Intergroup comparison showed no significant differences. Pericervical dentin
was reduced in all groups. The intragroup comparison only revealed a significant reduction
(P < .01) between PG F2 and F4. In addition, a significant decrease in pericervical
dentin (P < .05) was observed between PG F4 40/.06 and AS 40/.03. No significant differences
were observed between PG F2 25/.08 and SS 3 25/.04.
Conclusion
Increasing the instrumentation size from 25 to 40 significantly reduces the percentage
of unprepared areas regardless of the system used. In addition, using a modern system
with a regressive taper allows the maintenance of pericervical dentin without compromising
shaping efficacy in the apical third of the mandibular incisors with oval canals and
conservative access.
Key Words
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References
- The importance of endodontic access in locating maxillary and mandibular molar canals.J Can Dent Assoc. 1994; 60 (535-526): 527-532
- The impact of improved access and searching techniques on detection of the mesiolingual canal in maxillary molars.J Endod. 1989; 15: 82-83
- Comparative evaluation of the impact of minimally invasive preparation vs. conventional straight-line preparation on tooth biomechanics: a finite element analysis.Eur J Oral Sci. 2016; 124: 591-596
- Straight line access and coronal flaring: effect on canal length.J Endod. 2002; 28: 474-476
- Root canal culturing survey: single-visit endodontics.J Endod. 1985; 11: 511-513
- The anticurvature filing method to prepare the curved root canal.J Am Dent Assoc. 1980; 101: 792-794
- Canal orifice enlargement as related to biomechanical preparation.J Endod. 1983; 9: 463-470
- Cuspal deflection in molars in relation to endodontic and restorative procedures.J Endod. 1995; 21: 57-61
- Advanced digital photoelastic investigations on the tooth-bone interface.J Biomed Opt. 2001; 6: 224-230
- Modern molar endodontic access and directed dentin conservation.Dent Clin North Am. 2010; 54: 249-273
- Mechanisms and risk factors for fracture predilection in endodontically treated teeth.Endod Top. 2006; 13: 57-83
- Contracted endodontic cavities: the foundation for less invasive alternatives in the management of apical periodontitis.Endod Top. 2015; 33: 169-186
- Impacts of contracted endodontic cavities on instrumentation efficacy and biomechanical responses in maxillary molars.J Endod. 2016; 42: 1779-1783
- Fracture strength of endodontically treated teeth with different access cavity designs.J Endod. 2017; 43: 995-1000
- Influence of access cavity design on root canal detection, instrumentation efficacy, and fracture resistance assessed in maxillary molars.J Endod. 2017; 43: 1657-1662
- Impact of contracted endodontic cavities on root canal disinfection and shaping.J Endod. 2020; 46: 655-661
- Impacts of conservative endodontic cavity on root canal instrumentation efficacy and resistance to fracture assessed in incisors, premolars, and molars.J Endod. 2014; 40: 1160-1166
- Disinfecting oval-shaped root canals: effectiveness of different supplementary approaches.J Endod. 2011; 37: 496-501
- Effects of increased apical enlargement on the amount of unprepared areas and coronal dentine removal: a micro-computed tomography study.Int Endod J. 2018; 51: 684-690
- A micro-computed tomographic assessment of root canal preparation with a novel instrument, TRUShape, in mesial roots of mandibular molars.J Endod. 2015; 41: 1545-1550
- Influence of the apical preparation size and the irrigant type on bacterial reduction in root canal-treated teeth with apical periodontitis.J Endod. 2017; 43: 1058-1063
- The effectiveness of increased apical enlargement in reducing intracanal bacteria.J Endod. 2002; 28: 779-783
- Effect of different apical preparation sizes on outcome of primary endodontic treatment: a randomized controlled trial.J Endod. 2012; 38: 1309-1315
- Endodontic working width: current concepts and techniques.Dent Clin North Am. 2004; 48: 323-335
- Influence of instrument size on root canal debridement.J Endod. 2004; 30: 110-112
- Master apical file size–smaller or larger: a systematic review of microbial reduction.Int Endod J. 2015; 48: 1007-1022
- Infection control in retreatment cases: in vivo antibacterial effects of 2 instrumentation systems.J Endod. 2015; 41: 1600-1605
- Effect of apical third enlargement to different preparation sizes and tapers on postoperative pain and outcome of primary endodontic treatment: a prospective randomized clinical trial.J Endod. 2021; 47: 1345-1351
- Master apical file size - smaller or larger: a systematic review of healing outcomes.Int Endod J. 2015; 48: 639-647
- Case studies in modern molar endodontic access and directed dentin conservation.Dent Clin North Am. 2010; 54: 275-289
- Prevalence and extent of long oval canals in the apical third.Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000; 89: 739-743
- Increased apical enlargement contributes to excessive dentin removal in curved root canals: a stepwise microcomputed tomography study.J Endod. 2011; 37: 1580-1584
- Does the first file to bind correspond to the diameter of the canal in the apical region?.Int Endod J. 2002; 35: 264-267
- Influence of apical preparation size and irrigation technique on root canal debridement: a histological analysis of round and oval root canals.Int Endod J. 2019; 52: 1366-1376
- Comparison of GentleWave system and passive ultrasonic irrigation with minimally invasive and conventional instrumentation against LPS in infected root canals.Sci Rep. 2022; 12: 4894
Article info
Publication history
Published online: January 13, 2023
Identification
Copyright
© 2023 American Association of Endodontists.
