Practical aspects of dental operating microscopes in endodontics
Experience, radiograph and tactile sense are the important characteristics of traditional root canal treatment performed without a clear view of operating field. Advancement in the field of endodontics since past few decades have given endodontists important new tools to preserve natural dentition amongst which Dental operating microscope(DOM) is an invaluable and indispensable aid. DOM was introduced in the field of endodontics since the early 1990s. Using DOM with enhanced lighting and magnification helps to improve not only clinical skills, also enhance fine motor skills and visualization of the operating field. DOM guides endodontists to deal with treatment obstacles previously unrecognized or untreatable. Difficulty in locating and treating all the root canal systems is one of the factors that may lead to a nonhealing outcome after nonsurgical endodontic treatment. DOM helps to visualize fine details of the root canal system and carefully explore it, as a result, aids in cleaning and shaping .
This article elucidates different benefits of using DOM in the field of endodontics which ultimately guides towards the successful endodontic treatment.
• Carr’s oft-quoted statement, “You cannot treat what you cannot see,” has inspired a great number of dentists to add the microscope to their daily required equipments. Lighting in dental operating microscope is significantly improved because the light of a microscope is parallel to the line of sight and will provide two to three times the light of a surgical headlamp.Furthermore , DOM removes a lot of the guesswork.
The following are useful benefits from the use of the DOM:
1. Cracked tooth syndrome :
An isolated area of enamel may crack when a patient bites something hard or subjected to a blow or when a patient bites into something hard intact. Most of these superficial fractures are relatively undetectable with normal vision, but when viewed under high power magnification , hairline cracks are easily detected.
2. Detection of microfracture :
The DOM is an excellent instrument to detect microfractures that cannot be seen by the naked eye or by loupes. Under high magnification and focused light microfracture can be easily visible which can be assisted by Methylene blue staining of the microfracture area.
3. Detection of marginal leakage:
During a routine examination microleakage at the restorative interface may not be easily detected. As a result, caries may advance under the restoration for a long period of time. Minor occlusal angle force at gingival margin of restoration which is associated with pain and gingival swelling, often discloses a micromovement that is not visible to the eye but is clear and easily detected when viewed under high power.
4. Soft tissue evaluation:
Patients often present with pain and other related symptoms that indicate the presence of innammation or infection, but visual and radiographic evaluations do not always clearly identify the problem.Sometimes foreign bodies like nails,fish bones ,tooth chips between teeth results in swelling and bleeding of tissues which makes the location, identification, and removal of the challenging.However with the help of magnification of microscope it can be identified easily
5. Restorative Dentistry:
In deep dentinal caries, sometimes a minute pulp exposure may be undected which hinders future restoration .Using microscope in such case ,the floor of the cavity can be clearly visible and hence appropriate pulpal treatment like pulp capping ,pulpectomy can be done as required .
6. Endodontic therapy :
-high levels of magnification of dental operating microscope when approaching the floor of the pulp chamber, it is becomes easier to distinguish the roof of the chamber from the natural floor which eventually helps to reduce perforation. In the straight portion of the root canal system, even if located in the most apical part, can be easily seen and competently managed .
7. Locating orifice :
The potential for multiple canals and intracanal communications exists in root canal, and success and failure rests on locating and negotiating all of these canal abnormality. Selden described the use of a microscope operating at 7x power to locate calcified canals.
Many studies have reported the benefits of the operating microscope quantitatively by comparing the detection and negotiation of the second mesiobuccal canal (MB-2) in maxillary molars with and without vision enhancement. The operating microscope not only aids in the identification of missed or extra canals but helps minimize dredging during the identification process. In a study by Tzanetakis et al it was reported that dental operating microscope aided in locating four canals in mandibular second premolar .
8. Locating and removing the foreign objects
Finding and removing these canal blocking obstacles like broken files ,post , without perforating the root requires the vision and illuminating properties of a high-powered microscope and also the careful and circumferential troughing of the approximating dentin with an appropriate instruments like ultrasonic and diamond burs . Using dental operating microscope for troughing the dentine reduces the chance of perforation.
9. Retreatment :
Dental operating microscope may be helpful in retreatment cases like it aids in removal of guttapercha .Also by helping identifying the drawbacks from the previous treatment dental operating microscope aids towards success of endodontic treatment .
10. Repairing Perforations.
High magnification with illumination allows precise detection and visualisation of
perforations along straight, non-curved root canals. The selection of material used in perforation repair must be related to the type of perforation. Mineral trioxide aggregate (MTA) is proving to be an impressive material for both root-end filling and perforation repairs.
11. Endodontic Surgery:
In endodontic microsurgery dental operating microscope helps in minimal tissue and bone damage. They also concluded that the microscope and ultrasonic tips aids in the identification and treatment of the isthmus and may contribute to increased surgical success. In surgical endodontics, dental operating microscope aid s in carefull examination of the apical segment of the root end and perform an apical resection of the root and making class I cavity preparations along the longitudinal axis of the root. Surgical soft-tissue management is also greatly enhanced using microscope , leading to faster healing, less traumatic soft-tissue management using the microsurgical suturing techniques. There are others such as lateral root repairs, perforation repairs, external cervical invasive resorption repairs, and other resorptive repairs that also benefit from a microscopic approach.The development of special ultrasonic tips for retropreparation and associated instruments by Carr .
The images of dental operating microscope can be captured on computer or digital camera. It helps in better communication with concerned dentists or patients and the finally information for the patient record is also required.
Practical aspects of microscopes in endodontics:
It is almost impossible to undertake conventional endodontics under the microscope using direct vision. It is important, therefore, to use a good-quality dental mirror. A front surface mirror, silvered on the surface of the glass, gives an excellent undistorted reflected image. It is possible to manipulate the mirror head to view each root canal in an individual tooth without the need to move the microscope. It has been reported that the most common reason for frequently not using a DOM is the difficultyexperienced positioning it. The ideal operator zones are in the 7 to 12 o’clock positions for right-handed operators, and 5 to 12 o’clock for left. To maximize the access and quality of the view by this indirect means, the position of the patients head is important . The optimum angle between the microscope and the mirror is 45. After placement of a rubber dam ,the mirror must be placed away from the tooth within the confines of the rubber dam. If the mirror is placed close to the tooth, then it will be difficult to use other endodontic instruments.The dental practioner must ensure proper position because unless the operator is comfortable, even the shortest and simplest procedures are tiring. Although cost is frequently mentioned as the major barrier, however the truth is failure to understand and implement the positional and minimize discomfort necessary to effectively use an DOM. This failure has restricted its universal use in all endodontic cases.
Advances in endodontics over the past 20 years have been widespread and far-reaching. Endodontists now help patients retain teeth that would have been extracted in the past years. More development in magnification technologies and other treatment modalities will continue to improve endodontic outcomes in the years to come. Although the DOM is now recognized as a powerful auxillary in endodontics, it has not been accepted by all endodontists universally. The American Association of Endodontics suggests that all endodontists learn about the benefits of microscopes and incorporate the use of those devices in their daily practice .Thus With the aid of the DOM, structures can be easily seen that remain hidden to the naked eye and treatment can be carried out with far greater accuracy and predictably hence finally enhance proficiency of dental practioner and endodontists .