The images and videos of "The Root Canal Anatomy Project" blog were developed at the Laboratory of Endodontics of Ribeirao Preto Dental School - University of Sao Paulo - and may be freely used for attributed noncommercial educational purposes by educators, scholars, student and clinicians. It means that all material used should include proper attribution and citation ( In such cases, this information should be linked to the image in a manner compatible with such instructional objectives. Enjoy!

April 17, 2014

Radicular Groove: Maxillary Incisors

Radicular grooves (RGs) are a developmental groove in the root of teeth that may continue apically down the root. Grooves run from the beginning of the cemento-enamel junction (CEJ) and along the root surface to the apex. In most cases, the course of the grooves is straight.

Radicular grooves are often located on the palatal aspect of maxillary lateral incisors, and rarely on the labial root surface of the central incisors. RG were also reported in premolars and molars. According to their localization they are differentiated as distal, mesial and central patterns, with the distal position dominating, as it occurs in approximately 70% of cases. In the case of a distal localization, pathosis is often reported. The facial surface can be affected by the defect, albeit less frequently and with a predilection for the central maxillary incisors; however it is then properly termed a facial-radicular groove.

The prevalence of PRGs ranges between 2% and 5%, with 58% of the grooves featuring a length of more than 5 mm.

The grooves also vary in depth. Variation in groove depth can make a communication possible with the pulp cavity, however, deep grooves with direct communications with the pulp are seldom reported. With increasing depth of the groove, the thickness of the root cementum increases. At a morphological level, RGs are characterized by reduced dentin thickness and an increased cement layer, with a simultaneous modification of the odontoblasts. At a histological level, irregular dentin cement junctions have typically been identified.

The etiology of RGs is unknown. Similar to an invagination, this seems to be a peculiarity of tooth development accompanied by a further anomaly. Black was the first to describe the RG as a malfor-mation during embryo development in 1908. Atkinson surmised that the reason for its formation is that there is not enough space during tooth development in the maxilla, resulting in folding in the area of the Hertwig epithelial sheath. In the opinion of Goon et, this could also be an attempt at a root partition. According to recent studies, RGs may be caused by genetic changes. The predominance of the palato-gingival groove in the maxillary lateral incisors suggests the possibility that the groove results from an undesirable position of the lateral incisor during the period of maxilla growth. The tooth, although  still a germ, becomes surrounded by the central incisor, canine, and first premolar that are in a more advanced phase of dental development. Mineralization  of the crown of the maxillary  lateral incisor starts later, compared with the others, making this germ, under these conditions, highly susceptible to folding.

Clinical remarks
Morphological defects in dental structure (e.g. dens invaginatus,  talon cusp, and the palato-gingival groove) can be predisposing factors for the onset of inflammatory processes in the periodontal and/or pulp tissues. The funnel-like shape of the palato-gingival groove promotes the accumulation of difficult-to-remove plaque and calculus, at times making proper cleaning by the patient, or even by the dentist, nearly impossible. Most of the time RGs are clinically overlooked so that recurring clinical symptoms are often misdiagnosed because of the pathogenesis. As there is no epithelial closure, it is possible for microbes to settle in the groove. Depending on the morphology of the RG, localized periodontitis may develop, accompanied by pathosis. Periodontal pocket depths of more than 5 mm and increased dental mobility are typical findings. Moreover, in the case of deep RGs, a retrograde pulpitis may occur as a result of the so-called endodontic-periodontal lesion.

A good prognosis for prolonged tooth preservation also depends on whether combined periodontal and endodontic therapy is necessary. Several different procedures have been proposed for successful correction of RG. Current clinical treatment can correspond to that for inflammatory periodontal diseases. In some cases the palato-gingival groove can be seen in periapical radiographs as a fine parapulpal radiolucent line. In most cases, odontoplasty was carried out in combination with regenerative therapy. In the presence of periodontal disease, the therapeutical options can consist of grinding and flattening the affected area of the tooth with the groove, with the placement of a physical barrier between the tooth and soft tissue flap. The intraosseous defect, if present, can be grafted with porous hydroxyapatite. Other reported treatment procedures are careful root planing and cleaning, filling of the groove with amalgam or calcium sulphate, and intentional replantation after root planing and the insertion of Emdogain. The inherent difficulties in treating the palato-gingival groove make its diagnosis complex for practitioners. In some cases, the tooth was extracted due to its high mobility or in cases of bruxism.

The prognosis of pulp diseases and/or periapical inflammation in the presence of a palato-gingival groove is not very favorable, and depends in part on the groove’s extension, the depth of the groove, and the relation of the groove to the pulp cavity.


Arnold M.Palato-radicular groove associated with a bi-rooted maxillary incisor: a case report. Endo 2007;1:205-213.
Pécora JD, Conrado CA, Zuccolotto WG, et al.: Root canal therapy of an anomalous maxillary central incisor: a case report. Endod Dent Traumatol 1993; 9: 260-262.
Pécora JD, da Cruz Filho AM: Study of the incidence of radicular grooves in maxillary incisors. Braz Dent J 1992; 3: 11-16.
Pecora JD, Sousa Neto MD, Santos TC, et al.: In vitro study of the incidence of radicular grooves in maxillary incisors. Braz Dent J 1991; 2: 69-73.
Simon JH, Dogan H, Ceresa LM, et al.: The radicular groove: its potential clinical significance. J Endod 2000; 26: 295-298.

March 22, 2014

Maxillary First Molar: MB2

Roots Summit 2014

Greetings from the organizing committee of XI ROOTS SUMMIT 2014

'Roots Summit 2014' is an internationally acclaimed endodontic conference, attended by dentists from all around the world. 'Roots', an online endodontic forum that's shared and spread the knowledge and clinical expertise of many stalwarts in the field of Endodontics over more than a decade, conducts Summits once every two years. 
From Canada to US to Europe (2006 & 2010) and then to South America in 2012, Roots Summit has now crossed continents to be held, for the first time, in Asia; in Mahabalipuram near Chennai, India
We cordially invite all dentists; endodontists, general dentists, specialist dentist( any branch), graduate and post graduate students to participate in this mega event. 
For further details please click on the link:

With warm regards,
Dr. S. Mahalaxmi, MDS.
Organizing Chairperson,
Roots Summit 2014

Watch the movie and come to India

March 20, 2014

Publication IEJ


Aim: To assess the percentage volume of filling materials and voids in oval-shaped canals filled with either cold lateral condensation or warm compaction techniques, using micro-computed tomography (micro-CT). 

Methodology: Twenty-four single-rooted maxillary premolar teeth with oval-shaped canals were selected, the root canals prepared, and assigned to 2 groups (n=12), according to the filling technique: cold lateral compaction (CLC) or warm vertical compaction (WVC). Each specimen was scanned using a micro-CT device at an isotropic resolution of 12.5 μm. Percentage volume of root filling materials and voids were calculated, and data were statistically analyzed using Student t-test and Friedman's test, with a significance level of 5%. 

Results: Overall, mean percentage volume of gutta-percha, sealer and voids were 82.33 ± 3.14, 13.42 ± 2.91, and 4.26 ± 0.74, respectively, in the CLC group, and 91.73 ± 4.48, 7.70 ± 4.44, and 0.57 ± 0.44, respectively, in WVC group, with statistical significant difference between groups (p < 0.05). At the apical level, differences in the percentage volume of filling materials and voids between groups were not significant (p > 0.05). No root fillings were void-free. 

Conclusions: Warm vertical compaction produced a significantly greater volume of gutta-percha and a significantly lower percentage of voids than those achieved with cold lateral compaction. Distribution of sealer and voids within the root canal space after root filling procedure was unpredictable, irrespective of the root filling method.

March 9, 2014

The Root Canal Anatomy Project: Three Years Online

Begun formally in 2011, The Root Canal Anatomy Project completed 3 years online on 5th of March. This blog was developed in the Laboratory of Endodontics of Ribeirao Preto Dental School - University of Sao Paulo - with noncommercial and educational purposes. During this period, the blog was visited by people from 172 different countries with more than 370,000 page views. The videos were watched more that 100,000 times and the material was downloaded more than 10,000 times. Considering that root canal anatomy is a very specific subject in the endodontic field, we believe that the blog is achieving its goals. Thank you for your support and stay tuned for updates.

Maxillary First Molar: MB2

March 6, 2014

Mandibular First Molar (with Isthmuses)

Mandibular First Molar (Vertucci Type IV)

Publication Eur Arch Paediatr Dent

This was to investigate the root canal morphology of primary molar teeth using micro-computed tomography.

Primary maxillary (n=20) and mandibular (n=20) molars were scanned and analysed regarding the number, location, volume, area, structured model index (SMI), area, roundness, diameters, and length of canals, as well as the thickness of dentine in the apical third. Data were statistically compared by using paired-samplet test, independent sample t test, and one-way analysis of variance with significance level set as 5 %. 

Overall, no statistical differences were found between the canals with respect to length, SMI, dentine thickness, area, roundness, and diameter (p<0.05). A double canal system was observed in the mesial and mesio-buccal roots of the mandibular and maxillary molars, respectively. The thickness in the internal aspect of the roots was lower than in the external aspect. Cross-sectional evaluation of the roots in the apical third showed flat-shaped canals in the mandibular molars and ribbon- and oval-shaped canals in the maxillary molars. Conclusions External and internal anatomy of the pri-mary first molars closely resemble the primary second molars. The reported data may help clinicians to obtain a
thorough understanding of the morphological variations of root canals in primary molars to overcome problems rela-ted to shaping and cleaning procedures, allowing appro-priate management strategies for root canal treatment.

External and internal anatomy of the pri-mary first molars closely resemble the primary second molars. The reported data may help clinicians to obtain a thorough understanding of the morphological variations of root canals in primary molars to overcome problems related to shaping and cleaning procedures, allowing appropriate management strategies for root canal treatment.