April 1, 2006
by Jim Yeganegi, DDS
A 60-year-old male patient was seen for routine hygiene and oral health screening. At the time of scheduling his hygiene appointment he had informed the staff that he “had some dark brown spots, on his upper right teeth, which were sensitive to tooth brushing and cold temperatures.” He had requested that these areas be looked at first prior to his hygiene as he was concerned about experiencing pain during his hygiene treatment. The patient has a non contributory medical history. His dental history consists of hygiene recare and oral health screening. Although he maintains a regular recare schedule he admits that “he tends to avoid dental treatment, until something is really bothering him, due to high anxiety and phobia of the needle and drill.”
The patient presents with a chief concern of “brown areas, which are sensitive to cold and tooth brushing, near the gum line of the upper right teeth”. He had noticed the sensitivity for sometime but more recently his wife had informed him that when he smiled she could see dark spots on his teeth. Intra-oral exam reveals generalized mild gingivitis with supragingival plaque. The area of concern is the exposed root surfaces of teeth #’s 14,15,16 (Fig. 1). There are remnants of Class V composite restorations. Examination of his occlusion reveals that the upper/lower bicuspids and 1st molar are in crossbite. The patient uses a good quality automated toothbrush thus toothbrush abrasion is an unlikely cause of the tissue recession. There are no clinical signs of excessive bruxsim, however I suspect that the apical migration of the tissues maybe due to the position of these teeth and stresses that may be being exerted as the patient clenches and during centric occlusion. The patient was informed of the clinical findings and the following treatment protocol was presented to him. Reapplication of the bonded composite restorations to the root surfaces after they have been conditioned with the Erbium Dental Laser. He was informed that studies and clinical case histories have shown that the use of the laser in these cases offers several advantages:
1. Much less irritation to the pulpal tissues, versus using a conventional hand piece, as there is no heat generated while the laser is conditioning the tooth
2. Increased bond strengths have been reported using laser preparation in conjunction with acid etching and bonding
3. Most patients are able to have these procedures done without local anesthesia.
Topical anesthetic (EMLA) cream was applied to the buccal gingival tissues of teeth #’s14,15,16 to aid in cord placement. Small pieces of untreated packing cord were place in the buccal sulci of these teeth (Fig. 2) to help maintain a dry operating field. The teeth are now ready to be “laser anesthetized”. Although the exact physiological mechanism of how laser anesthesia is achieved is unclear, it is thought that the patient/tooth are being conditioned to the feel of the laser; as well, there may be depolarization of the pulpal tissues through disruption of the sodium potassium pump.
In my practice I use The Rabbit Technique (taught by Mark Colona DMD, USA) for laser anesthesia. The laser tip is held 1cm away and perpendicular to the root surface. It is set at 20hz and 300mj of energy and activated for 90 seconds. Although the laser is at maximum energy it is not ablating any of the target tissue since optimum ablation occurs at the distance of .5-1mm away from the laser tip. At a distance of 1cm the defocused laser light is conditioning the pulp and the the tooth to the sensation of the laser. The tooth is now tested, with air, to see if desensitization has taken place and that the patient is comfortable with the feel of the laser.
The next step is the preparation of the root surfaces. Since the root surface ablates quiet easily we can use lower laser energy to achieve the desired effect. The laser tip is held 1mm away and perpendicular to the root surface then activated. The tip is moved, over the area to be prepared, in a slow controlled manner. Once finished and dried the treated surface will appear “frosty”. This is what a laser etched/conditioned tooth surface looks like (Fig. 2).
The enamel is beveled using a fine diamond and the tooth is now ready for a bonded composite restoration. Studies have shown that laser preparation in conjunction with acid etching and bonding yield a high bond strength thus decreasing the likelihood of debonding in these high flexural areas. The prepared surface was etched with 37% phosphoric acid for 10 seconds followed by a rinse and blot drying to allow for wet bonding. After the application of the adhesive a thin layer of flowable composite was placed and cured. A hybrid composite was used to restore the root surface. The packing cord was removed and the restoration finished, polished and final cured (Fig. 3). The patient was extremely happy with the treatment particularly because he had the procedure done without any anesthesia and he could have his hygiene done without any discomfort or sensitivity.
My experiences have shown that the use of the laser in treatment of these simple cases allows for placement of long-lasting, esthetic restorations as well as increasing case acceptance. It has been a great practice builder and makes treatment of such cases, simple, fast and rewarding for both the patient and office staff.
Dr. Jim Yeganegi is in private practice in Vancouver, BC. Graduating from Tufts School of Dental Medicine, in Boston Massachusetts, with a Doctor of Dental Medicine Degree. He has had two years of Continuing Education in Laser Dentistry and have been certified by the Institute For Laser Dentistry in Canada and the Academy of Laser Dentistry in USA.
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