Impact of Conservative and Conventional Endodontic Access Designs on Pericervical Dentin Integrity in Single-Rooted Premolars: Insights from an In Vitro Micro-CT Investigation

Angela Gusiyska, Miryana Raykovska, Elvira Gyulbenkiyan

Abstract: Preservation of pericervical dentin (PCD) is critical for maintaining the biomechanical integrity and long-term success of endodontically treated teeth. This study evaluated the impact of conservative and conventional access cavity designs on PCD preservation in single-rooted premolars using micro?computed tomography (micro-CT). Thirty-five extracted human premolars were randomly allocated into two experimental groups - conventional (Group I) and conservative (Group II) endodontic access - and one control group (Group III). Within Groups I and II, canals were prepared using XP-endo Shaper, ProTaper Next, or a hybrid step-back technique (n = 5 per subgroup). Specimens underwent pre- and post-instrumentation scanning using high-resolution micro-CT system (voxel size 10 ?m). Quantitative evaluation included the percentage reduction in PCD thickness, dentin removal (mm), and treated/untreated canal surface ratio. Compared to conventional access (26.08 ? 9.88%), conservative access cavities preserved more PCD (23.48 ? 9.77%).. Mean dentin removal was lower for conservative access (0.216 mm) than conventional ( 0.30 mm) (p < 0.05). XP-endo Shaper achieved the highest shaping efficiency with minimal dentin loss, whereas ProTaper Next exhibited the greatest dentin removal. The hybrid step-back technique showed the lowest efficiency. Coronal flaring with Gates-Glidden burs significantly increased dentin loss and risk of fissure formation in the PCD region. Micro-CT analysis confirmed that conservative, microscope-assisted access combined with adaptive NiTi systems optimises the balance between canal shaping and dentin preservation. Protecting the pericervical dentin is critical to prevent root weakening and to enhance long-term fracture resistance in endodontically treated premolars.

Keywords: pericervical dentin preservation, conservative endodontic access, micro?computed tomography (micro-CT), nickel?titanium instrumentation, fracture resistance

How to Cite?: Angela Gusiyska, Miryana Raykovska, Elvira Gyulbenkiyan, "Impact of Conservative and Conventional Endodontic Access Designs on Pericervical Dentin Integrity in Single-Rooted Premolars: Insights from an In Vitro Micro-CT Investigation", Volume 14 Issue 10, October 2025, International Journal of Science and Research (IJSR), Pages: 1343-1349, https://www.ijsr.net/getabstract.php?paperid=SR251027002043, DOI: https://dx.doi.org/10.21275/SR251027002043