PhD Thesis Defence

Click here to download the Thesis [only in Portuguese]

Click here to download all references [in full]

Thesis Committee

Prof. Dr. Manoel D. Sousa Neto (supervisor)

Prof. Dr. Jesus Djalma Pécora

Prof. Dr. Gustavo De Deus

Prof. Dr. Antônio Miranda da Cruz Filho

Prof. Dr. Antônio Paulino Ribeiro Sobrinho

PhD Thesis Defence Prof. Dr. Marco Versiani Part 1

View more presentations from Prof. Dr. Marco Versiani.

PhD Thesis Defence Prof. Dr. Marco Versiani Part 2

View more presentations from Prof. Dr. Marco Versiani.

Abstract

The purpose of this ex vivo study was to evaluate the biomechanical preparation and obturation of root canals using ProTaper, WaveOne, Reciproc and Self-Adjusting File systems. It was evaluated: 1) area, perimeter, roundness, major diameter, minor diameter, surface area, volume and SMI after biomechanical preparation, using microcomputed tomography (μTC), 2) percentage volume of voids in the obturation material by means of μTC, 3) bond strength (BS) and type of failure after the push-out test, and 4) the analysis of the interface dentin / filling material using scanning electron microscopy (SEM). One-hundred human mandibular canines were scanned in the SkyScan 1174v.2 device. After preparing the coronal third of the canals, the teeth were divided into 4 groups (n=25), according to the biomechanical preparation system used: ProTaper, WaveOne, Reciproc, and Self-Adjusting File (SAF). After the second μTC, eigthteen specimens of each group were assigned to two groups (n=9), according to the obturation technique: the Modified Continuous Wave of Condensation Technique and the technique recommended by the manufacturer. The remaining seven specimens of each group were used as negative and positive controls. After scanning, the obturated specimens were sectioned perpendicularly to its long axis into 1-mm slice thickness of the coronal, middle and apical thirds. The bond strength (BS) was performed by the push-out test and, after dislodgments, the failures were observed in a digital microscope. The specimens were processed for SEM analysis to observe bonding interface formation and resin tag density using a four-step scale method. Overall, the analysis of the biomechanical parameters showed that the most significant changes in the root canal occurred in the ProTaper group and WaveOne groups. Reciproc results were in an intermediate level and smaller changes were observed in the SAF group (ANOVA, p<0.05). In the coronal third, the Modified Continuous Wave of Condensation Technique showed a lower percentage volume of voids than the technique recommended by the manufacturer (Kruskal-Wallis test, p<0.05). After the push-out test, the analysis indicated the mean BS (MPa) was significantly higher in specimens filled by the manufacturer's technical than the Modified Continuous Wave of Condensation Technique (t test for independent samples, p<0.05). The adhesive failures were frequent in all groups. The Modified Continuous Wave of Condensation Technique showed the highest percentage of adhesive failure in dentin while in the technique recommended by the manufacturer, mixed failure was predominant. Overall, in SEM analysis, no tags were observed in most of the specimens filled by the Modified Continuous Wave of Condensation Technique. When present, they were small and irregularly distributed. The specimens filled by the technique recommended by the manufacturer showed long and well-distributed tags, especially in the apical third (Friedman test, p<0.05). It was concluded that all systems promoted root canal changes after the biomechanical preparation, the obturation technique recommended by the manufacturer resulted in a higher volume of voids in the coronal third and BS of the Modified Continuous Wave of Condensation Technique group.

(From left to right) Prof. Dr. Antônio Miranda Cruz Filho, Prof. Dr. Jesus Djalma Pécora, Prof. Dr. Marco A. Versiani, Prof. Dr. Elizeu A. Pascon, Prof. Dr. Manoel D. Sousa Neto, Prof. Dr. Gustavo de Deus, Prof. Dr. Antônio Paulino Ribeiro Sobrinho

The Root Canal Anatomy Project: One Year Online

Begun formally in 2011, The Root Canal Anatomy Project will complete one year online next Monday, 5th 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 140 different countries with more than 66,500 page views. The videos were watched more that 23,000 times and the material was downloaded more than 2,000 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.

Root Canal Anatomy Project

Statistics From March 2011 to March 2012

Maxillary Fusioned Molars

Fusion is commonly identified as the union of two distinct dental sprouts which occurs in any stage of the dental organ. They are joined by the dentine; pulp chambers and canals may be linked or separated depending on the developmental stage when the union occurs. This process involves epithelial and mesenchymal germ layers resulting in irregular tooth morphology (1). Moreover, the number of teeth in the dental arch is less than normal. A review of the literature reveals great difficulty in correctly differentiating fusion and gemination. For a differential diagnosis between these anomalies, the dentist must carry out a highly judicious radiographic and clinical examination. The aetiology of fusion is still unknown, but the influence of pressure or physical forces producing close contact between two developing teeth has been reported as one possible cause (2). Genetic predisposition and racial differences have also been reported as contributing factors. This anatomic irregularity occurs more often in the deciduous than in the permanent dentition. Only a few cases of fusion involving molar and premolar teeth have been reported (3-5) whereas, in both dentitions, the prevalence is higher in the anterior region (6-9). Cases of bilateral fusion are less frequent than unilateral fusion (6). Turell and Zmener (3) described a case of fusion involving a mandibular third molar and fourth molar (distomolar). Unfortunately, most of these fusions require surgical removal because of their abnormal morphology and excessive mesiodistal width, which cause problems with spacing, alignment and function (6,8). In the anterior region this anomaly also causes an unpleasant aesthetic tooth shape due to the irregular morphology. These teeth also tend to be greatly predisposed to caries and periodontal disease and, in some cases, endodontic treatment is very complicated (7,10). Fusion can occur between teeth of the same dentition or mixed dentitions, and between normal and supernumerary teeth (3,7-9,11,12). In these cases, the number of teeth in the dental arch is also normal and differentiation from gemination is clinically difficult or impossible. A diagnostic consideration, but not a set rule, is that supernumerary teeth are often slightly aberrant and present a cone-shaped clinical appearance. Thus, fusion between a supernumerary normal tooth will generally show differences in the two halves of the joined crown. However, in gemination cases the two halves of the joined crown are commonly mirror images. Fused teeth usually present asymptomatically. In fact, the co-operation of practitioners with expertise in multiple areas of dentistry is important to create or achieve functional and esthetic success in these cases. Several treatment methods have been described in the literature with respect to the different types and morphological variations of fused teeth, including endodontic, restorative, surgical, periodontal and/or orthodontic treatment (3-9,12). (Source: Nunes et al. 2002. Full text).

 

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Root Canal Anatomy: A Brief History

A Brief History of the First Studies on the Root Canal Anatomy

View more presentations from Prof. Marco Versiani.

New Video Formats

The Video Files category includes a wide range of video formats, which use different codecs to encode and compress video data. Until now, the Root Canal Anatomy Project has provided their users with only .WMV extension which is a Windows-based format (http://www.fileinfo.com/extension/wmv). Considering the arising of popular devices that use different video formats, the Root Canal Anatomy Project is starting to provide our users with formats compatible with them. Click on the below links to download the videos of the root canal anatomy of all teeth from the mandibular and maxillary archs converted to different formats. Enjoy!

Mandibular teeth for Windows
Mandibular teeth for iPod
Mandibular teeth for iPhone & iPod Touch
Mandibular teeth for iPhone 4
Mandibular teeth for iPad

Maxillary teeth for Windows
Maxillary teeth for iPod
Maxillary teeth for iPhone & iPod Touch
Maxillary teeth for iPhone 4
Maxillary teeth for iPad

PowerPoint Presentations

Dear readers,

Considering some requests, the Root Canal Anatomy Project is providing presentations in unlocked, editable PowerPoint (.pptx) files with all images and videos developed during the last year in our laboratory. Just click the link and download the file (how to download a file?). It is ready to be used. Have fun!

Maxillary Central Incisor
Maxillary Lateral Incisor
Maxillary Canine
Maxillary First Premolar
Maxillary Second Premolar
Maxillary First Molar
Maxillary Second Molar
Maxillary Third Molar

Mandibular Incisors
Mandibular Canine
Mandibular First Premolar
Mandibular Second Premolar
Mandibular First Molar
Mandibular Second Molar
Mandibular Third Molar

Mandibular Second Molar: Radix Entomolaris

       Mandibular molars can have an additional root located lingually (the radix entomolaris) or buccally (the radix paramolaris). The presence of a separate RE in the first mandibular molar is associated with certain ethnic groups. In African populations a maximum frequency of 3% is found, while in Eurasian and Indian populations the frequency is less than 5%. In populations with Mongoloid traits (such as the Chinese, Eskimo and American Indians) reports have noted that the RE occurs with a frequency that ranges from 5% to more than 30%. Because of its high frequency in these populations, the RE is considered to be a normal morphological variant (eumorphic root morphology). In Caucasians the RE is not very common and, with a maximum frequency of 3.4 to 4.2%, is considered to be an unusual or dysmorphic root morphology. The etiology behind the formation of the RE is still unclear. In dysmorphic, supernumerary roots, its formation could be related to external factors during odontogenesis, or to penetrance of an atavistic gene or polygenetic system (atavism is the reappearance of a trait after several generations of absence). In eumorphic roots, racial genetic factors influence themore profound expression of a particular gene that results in the more pronounced phenotypic manifestation. Curzon suggested that the ‘three-rootedmolar’ trait has a high degree of genetic penetrance as its dominance was reflected in the fact that the prevalence of the trait was similar in both pure Eskimo and Eskimo/Caucasian mixes. An RE can be found on the first, second and third mandibular molar, occurring least frequently on the second molar. Some studies report a bilateral occurrence of the RE from50 to 67%. Bolk reported the occurrence of a buccally located addi tional root: the RP. This macrostructure is very rare and occurs less frequently than the RE. The prevalence of RP, as observed by Visser, was found to be 0% for the first mandibular molar, 0.5% for the second and 2% for the third molar. Other studies have, however, reported RP in first mandibular molars. The RE is located distolingually, with its coronal third completely or partially fixed to the distal root. The dimensions of the RE can vary from a short conical extension to a ‘mature’ rootwith normal length and root canal. Inmost cases the pulpal extension is radiographically visible. In general, the RE is smaller than the distobuccal and mesial roots and can be separate from, or partially fused with, the other roots. A classification by Carlsen and Alexandersen describes four different types of RE according to the location of the cervical part of the RE: types A, B, C and AC. Types A and B refer to a distally located cervical part of the RE with two normal and one normal distal root components, respectively. Type C refers to a mesially located cervical part, while type AC refers to a central location, between the distal and mesial root components. This classification allows for the identi fication of separate and nonseparate RE. In the apical two thirds of the RE, a moderate to severe mesially or distally orientated inclination can be present. In addition to this inclination, the root can be straight or curved to the lingual. According to the classification of De Moor et al., based on the curvature of the separate RE variants in bucco-lingual orientation, three types can be identified. Type I refers to a straight root/root canal, while type II refers to an initially curved entrance which continues as a straight root/root canal. Type III refers to an initial curve in the coronal third of the root canal and a second curve beginning in the middle and continuing to the apical third. The RP is located (mesio) buccally. As with the RE, the dimensions of the RP can vary from a ‘mature’ root with a root canal, to a short conical extension. This additional root can be separate or nonseparate. Carlsen and Alexandersen describe two different types: types A and B. Type A refers to an RP in which the cervical part is located on the mesial root complex; type B refers to an RP in which the cervical part is located centrally, between the mesial and distal root complexes.An increased number of cusps is not necessarily related to an increased number of roots; however, an additional root is nearly always associated with an increased number of cusps, and with an increased number of root canals (From Calberson et al. 2007 JOE 33(1):58-63).

 

Keywords: micro-computed tomography, micro-ct, marco versiani, micro-computer tomography, high resolution x-ray tomography, dental anatomy, root canal anatomy

Impressions from IAE Meeting

The mission of The International Academy of Endodontics (http://endodonticacademy.org) is to improve the oral health of the public by promoting the highest quality of non-commercial endodontic and scientific continuing education for its membership. The Academy encourages its members to pursue scholarship, research and the highest standards of clinical excellence to advance the art and science of endodontics. Its vision is to create the foremost international endodontic and scientific educational experience for endodontists and their colleagues in dentistry, medicine and science. The International Academy of Endodontics was formed by a group of clinicians committed to the highest standards of continuing education. The membership has been kept small by design and will not exceed 125 members. Believing that clinical excellence is a lifelong pursuit, their members seek out speakers from many areas in biology, medicine and dentistry who are exceptional leaders in their field. Their organization is a non-profit public organization and accepts no commercial affiliations.

The IAE meets at the same time and in the same location each year in Dallas. The goal of the meeting was to provide advanced knowledge and understanding, to give inspiration through basic science and clinical leadership, and to provide serious mentorship for all attendees.  The programs include long and short oral presentations and table clinics that serve to integrate basic and clinical science on topics directly or indirectly related to endodontics.

(click here for the program: http://endodonticacademy.org/index.php/2012sched)

In 2012, I have the honour to be one of the invited speakers in their first meeting. I know that I am in the history of IAE from now. It was an unforgettable experience that will follow me forever. It was a high level event and very well-organized. I was so impressed with the commitment of all people involved in its organization. Dr. Gary Carr and Carlos Murgel were perfect hosts and all members were so friendly with me. What a nice and positive ambient! I felt so confortable as I was in my own place. Thank you IAE members for the warmest reception and unforgettable moments during the last weekend.

Dallas Downtown (view from the Fairmont Hotel)

Meeting room (Fairmont Hotel)

Meeting room (Fairmont Hotel)

IAE's members

IAE's members

Dr. Versiani's presentation (Courtesy from Dr. Peter Endo)

Dr. Versiani's presentation (Courtesy from Dr. Peter Endo)

Dr. Versiani and Dr. Sashi Nallapati

Dr. David Figdor, Dr. Jorge Vera and Dr. Versiani

Dr. Robert Kaufmann, Dr. Ove Peters and Dr. Versiani

Dr. Versiani and Dr. Rajiv Patel

Dr. Jose Luis Marcos-Arenal, ... and Dr. Versiani

Dr. Versiani and Dr. Carlos Murgel

Dr. Versiani and Dr. Kim Lewis

Dr. Richard Mullins, Dr. Versiani and Dr. Robert Goldberg

Dr. Richard Mullins, Dr. Gary Carr, Dr. Versiani and Dr. Peter Cancellier

Dr. David Figdor, Dr. Versiani, Dr. Mark Dreyer and Dr. Garland Forbes

Dr. Carlos Murgel and Dr. Versiani (Courtesy from Dr. Peter Endo)