Operating microscope in endodontics Clinical morphology of root canal system Restorative dentistry Endodontics II. 15.4.2021 Dentistry •Working field is limitated to small space of oral cavity. •Difference in size of dental instruments and size of hand of dentists. • •Magnification increases amount of visual informations -> increased precision. • History of magnification •1876 oftalmologist Edwin Seamisch started using binocular loupes in general surgery. •1978 started development of special microscope for use in dentistry. •1981 DentiScope •1990 Dr Gabriele Pecora presented for the first time use of DOM during root apectomy with retrograde obturation. •1990 Garry Carr introduced DOM with galileans optics. • Possibilities of magnification •Reduce the distance between the object and eye •Loupes •Dental operating microscope Working distance • •It is determined by high -> individual parameter. •Ergonomical perfect position. •Focusing object of interest into working distance. Depth field •Effective focus range •It is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. Human eye •It can detect maginal ridge of size 0,2mm. •It can control hand movement in 1-2mm precision. •Minimal focusing distance is 15cm. •Magnification only by bringing eye closer to point of interest. •From practical point of view bring face of dentists to the face of patients is not possible. •Ability eye to focus to close objects decrease with age. •Low level of ergonomics. • • • Loupes •Allows to focus to one object. •Working distance and magnification determined by construction of loupes. •Eye convergence -> not suitable for long period of time. • Loupes •Galilean design •Prizmatic – Kepler design Galilean design •Wider field of view •Lighter •Magnification limited •Optical aberations? Prizmatic – Kepler design •Bigger construction •Supreme quality of optical system •Heavier •Magnification up to 6x TTL – throught the lens Dental operating microscope •Magnification 4x-40x •High cost •High performance magnification. •Four hand dentistry •At 20x human eye can differentiate detail 0,006 mm. •At 20x magnification we can control hand movement • in range 0,01 – 0,02 mm. Advantages of using DOM •Ergonomics •Quality of treatment •Comunication with patients •Documentation •Marketing Ergonomics Mounting DOM • • https://www.youtube.com/watch?v=DW9Q5UNAEsI Accessories •Beam splitter for assistance or for camera. Way of communication •Photography •Video •Live streaming of treatment or examination Documentation •Photography and video •Patients files •Analysis of treatment protocols Dental operating microscope in dentistry •Direct illumination of operation field. •Easier and accurate identification of root canal orifices. •Identification of root canal anomalies. •Minimal invasive approach. •Lower fatigue. •Communication with patient. • Clinical morphology of root canal system Terminology Cohen-Pathways-of-the-Pulp-9th_edition-202 Root canal doesn’t run in straight line, usually its mesially curved. It can split in branches, not rounded diameter. Apical anatomy •http://theendoacademy.com/wp-content/uploads/2013/04/apex-LargeType-001-620x604.jpg Apical anatomy Guidelines for localization orifices of root canals •Centrality: The floor of the pulp chamber is always located in the center of the tooth at the level of the CEJ. •Symmetry: Except for the maxillary molars, canal orifices are equidistant from a line drawn in a mesiodistal direction through the center of the pulp chamber floor. Except for the maxillary molars, canal orifices lie on a line perpendicular to a line drawn in a mesiodistal direction across the center of the pulp chamber floor. •Color change: The pulp chamber floor is always darker in color than the walls. •Orifice location: The orifices of the root canals are always located at the junction of the walls and the floor; the orifices of the root canals are always located at the angles in the floor-wall junction; and the orifices of the root canals are always located at the terminus of the roots’ developmental fusion lines. •More than 95% of the teeth these investigators examined conformed to these spatial relationships • Failures during access preparation Opening access is localized on line between vestibular and oral cusp. For lower premolars the opening access must respect lingual inclination of crown. For molars the correct starting location is on the central groove halfway between the mesial and distal boundaries. •Completly remove roof of pulp chamber. •Straight line access into root canal. • Failures during access preparation • Maxillary central incisor •The access cavity has triangular outline. •1 root – 1 root canal • Maxillary central incisor • Length of tooth 23,5mm Length of crown 10,5mm Length of root 13mm Width of crown 8,5mm Width of cervical area 7mm Maxillary lateral incisor •The access cavity is triangular and reproduces the shape of the endodontic space. •1 root – 1 root canal In 53% cases we can find distal curvature in the apical third of the root. Maxillary lateral incisor • Length of tooth 22mm Length of crown 9mm Length of root 13mm Width of crown 6,5mm Width of cervical area 5mm Maxillary canine •The access cavity of the pulp chamber has an oval shape, going from the cusp to the cingulum of the coronal cervical one-third. •1 root – 1 root canal. Maxillary canine • Length of tooth 27 mm Length of crown 10 mm Length of root 17 mm Width of crown 7,5 mm Width of cervical area 7mm Maxillary first premolar •Vestibular and palatal pulp horn. •The access preparation for the maxillary first premolar is oval or slot shaped. •P root – 1rc. •V root – 1rc 95 %, 2rc 5%. Maxillary first premolar • Length of tooth 22,5 mm Length of crown 8,5 mm Length of root 14 mm Width of crown 7 mm Width of cervical area 5 mm Maxillary second premolar •Vestibular and palatal pulp horn. •The access preparation for the maxillary second premolar is oval or slot shaped. Maxillary second premolar • Length of tooth 22,5 mm Length of crown 8,5 mm Length of root 14 mm Width of crown 7 mm Width of cervical area 5 mm Maxillary first molar •The maxillary first molar is the largest tooth in volume and one of the most complex in root and canal anatomy. •The access cavity has a rhomboid shape, with the corners corresponding to the four orifices. •P root – 1rc (55% B curved). •DB root – 1rc 96%, 2rc 4%. •MB root – 1rc 5-40%%, 2rc 95-60% MB2 •Localised on the line connectin MB a P root canal, under dentin shoulder. •Removing shoulder-> US StartX 2. First upper molar • Length of tooth 20/22mm Length of crown 7,5mm Length of root 12/13mm Width of crown 10mm Width of cervical area 8mm Second upper molar •When four canals are present, the access cavity has a rhomboid shape •If only three canals are present, the access cavity is a rounded triangle with the base to the buccal. •If only two canals are present, the access outline form is oval •P root – 1rc (37% B curved). •DB root – 1rc. •MB root – 1rc 57%, 2rc 23%. •MB and DB fused – 16%. • Second upper molar • Length of tooth 19/21mm Length of crown 7mm Length of root 11/12mm Width of crown 9mm Width of cervical area 7mm Mandibular central and lateral incisor •High difficulty – tiny proportions of tooth •The external outline form may be triangular or oval, extended to incizal edge. •1 root – 1 root canal 75%, 2 root canals 25% Mandibular central incisor • Length of tooth 22 mm Length of crown 9,5 mm Length of root 12,5 mm Width of crown 5 mm Width of cervical area 3,5 mm Mandibular lateral incisor • Length of tooth 23,5 mm Length of crown 9,5 mm Length of root 14 mm Width of crown 5,5 mm Width of cervical area 4 mm Mandibular canine •The access cavity for the mandibular canine is oval or slot shaped. •1 root – 1 rc in 94%, 2 rc in 6% Mandibular canine • Length of tooth 23 mm Length of crown 10 mm Length of root 17 mm Width of crown 7,5 mm Width of cervical area 5,5 mm Mandibular first premolar •Two pulp horns. Lingual inclination of crown. •The access preparation is oval or slot shaped. •1 root – 1rc 74%. • Mandibular first premolar • Length of tooth 24,5 mm Length of crown 8,5 mm Length of root 14 mm Width of crown 6 mm Width of cervical area 5 mm Mandibular second premolar •Two pulp horns. Lingual inclination of crown. •The access preparation is oval or slot shaped. •1 root – 1rc 97%. Mandibular second premolar • Length of tooth 24,5 mm Length of crown 8,5 mm Length of root 14 mm Width of crown 7 mm Width of cervical area 5 mm Mandibular first molar •It is often extensively restored, and it is subjected to heavy occlusal stress. Consequently, the pulp chamber frequently has receded or is calcified. •The access cavity is typically trapezoid or rhomboid, regardless of the number of canals present. •M root – 1rc 12%, 2rc 87%, 3rc 1% •D root – 1rc 70%, 2rc 30%. Mandibular first molar • Length of tooth 21,5mm Length of crown 7,5mm Length of root 14mm Width of crown 11mm Width of cervical area 9mm Mandibular second molar •The access cavity is typically trapezoid or rhomboid. •M root – 1kk 27%, 2kk 73%. •D root – 1kk 92%, 2kk 8%. Mandibular second molar • Length of tooth 20mm Length of crown 7mm Length of root 13mm Width of crown 10mm Width of cervical area 8mm Sources •Cohen Pathways of the Pulp - 10th edition •Cohen Pathways of the Pulp - 9th edition •Laser in endodontics •