Background <p>An endodontic sealer forms an interface between gutta-percha and root canal walls. Ideally, the sealer layer should be void-free, thin, uniform, well-adapted to the dentinal walls, and exhibit good tubular penetration, which contributes to a successful endodontic treatment. Vibrospiral is a novel sealer-placing instrument that uses piezoelectric energy to improve the quality of the sealer layer coated on root canal walls. This study aimed to compare the efficacy of Endoactivator, Lentulo spiral and Vibrospiral in sealer distribution and adaptation within root canals by evaluating four parameters: percentage of sealer coverage on canal walls, depth of sealer penetration into dentinal tubules, sealer layer thickness, and adaptation of the sealer to dentinal walls. Confocal Laser Scanning Microscopy (CLSM) was employed to measure the percentage of sealer coverage and the depth of tubular penetration. Scanning Electron Microscopy (SEM) was used to assess the thickness of the sealer layer and to qualitatively evaluate its adaptation to the canal walls.</p> Methods <p>Forty-five disinfected and decoronated human mandibular premolars with single canals were biomechanically prepared. The specimens were randomly allocated equally across three groups, with 15 samples per group (<i>n</i> = 15), based on the sealer application technique: Group 1 – Endoactivator, Group 2 – Lentulo spiral, and Group 3 – piezoelectrically driven Vibrospiral. Thin transverse sections from the apical, middle and coronal thirds of the samples were observed under a CLSM to evaluate the extent of canal wall coverage with sealer. A novel scoring system was devised to score the same. The depth of tubular penetration of the sealer was also noted under CLSM. Transverse sections of obturated root samples were subjected to SEM analysis to assess the sealer adaptation to the canal wall and the thickness of the sealer layer. The data was statistically analysed using ANOVA and the Tukey test. The statistical significance level was set at ≤ 0.05.</p> Results <p>Vibrospiral placed a thin, uniform, and well-adapted sealer layer with a higher depth of penetration of the sealer owing to its vibratory motion compared to Lentulo spiral and Endoactivator. The extent of canal wall coverage with sealer was also highest for the Vibrospiral group.</p> Conclusions <p>The novel sealer placing instrument, Vibrospiral, can efficiently coat the root canal walls thoroughly and consistently with a thin, uniform, void-less and well-adapted layer of sealer, depicting improved penetration of the sealer in the dentinal tubules.</p>