April 1, 2001
by Oral Health
The SLSA program is based on current, referenced literature and consists of 40 questions, answers, rationales and references. Answers appear at the end of each quiz.
Dentists who complete the 15 question quiz in the November, 2001 issue of Oral Health may be eligible to receive continuing education points. The names and license numbers of all who complete the quiz will be forwarded to their respective provincial licensing authorities.
In endodontic therapy, passage of root filling material into the periapical space will
A. result in a significantly higher failure rate.
B. prevent periapical healing.
C. ensure an effective apical seal.
D. accelerate healing.
Experimental data have shown that material extruded into the apical periodontal space results in the necrosis of the periodontal ligament and bone resorption adjacent to the material. Extruded material does not necessarily prevent periapical healing, but is often associated with a defective apical seal. Extruded material may slowly disappear, with a return to a normal radiographic appearance. The reaction can be mild, but it can also be serious, particularly in the case of mandibular premolars and molars if filling material finds its way into the mandibular canal. If this occurs, persistent pain, hyperaesthesia, and paraesthesia can result. Some materials are neurotoxic; others, because of their expansion upon setting, can cause nerve compression.
If N2 and paraformaldehyde materials are extruded into the mandibular canal, they must be removed as soon as possible. With other materials healing is unpredictable and other factors should be considered before intervening surgically. If nerve compression is suspected, surgical intervention is required to remove the material and decompress the nerve. Nerve compression, left untreated, results in Wallerian degeneration and necrosis of tissues.
Measures must be taken toward selecting the least toxic filling materials and using all materials in a controlled manner. Cases with overextended root fillings should be carefully observed.
– Gunraj, M.N., West, N.M. Assessment of endodontically treated teeth for restorative procedures. Compend Contin Educ Dent. 11(7), 1990.
– Neaverth, E.J. Disabling complications following inadvertent overextension of a root canal filling material. J Endod 15:135-139, 1989.
The increased demand for aesthetic dentistry has introduced periodontal plastic surgery to enhance the aesthetic component of the periodontium. Which of the following would you consider for such care in the anterior maxilla?
1. An extraction site with labio lingual tissue loss.
2. Gingival hyperplasia.
3. Dehiscence recession.
4. A three-wall intrabony pocket.
A. 1, 2, 3
B. 1 and 3
C. 2 and 4
D. 4 only
E. All of the above
Where alveolar tissue is lost after extraction, ridge augmentation techniques are used to restore the reduced area. In the case of a single pontic, management of the problem consists of harvesting a connective tissue graft from the palate and suturing this to the underlying periosteum at the edentulous site. Where an implant is to be used , the ridge augmentation can take place during the implant placement, if sufficient bone for the implant is present. In a patient with inadequate bone, augmentation must be completed before the implant is inserted.
A patient with gingival hyperplasia can best be treated using an external bevel gingivectomy technique which allows retention of the all-important interdental papillae necessary for favourable aesthetics.
Dehiscence recession can be dealt with by a pedicle flap but, in recent times, a free autogenous graft of connective tissue from the palate (with the epithelial component removed) is inserted into an envelopelike pouch at the recipient site. This would appear to provide the most stable result.
A three-wall intrabony pocket on an anterior tooth will not require aesthetic plastic surgery. After flap reflection and the elimination of granulation tissue from the pocket, new bone growth will occur from surrounding bone.
1. Pasquinelli, K.L. Periodontal plastic surgery. J Calif Dent Assoc 27:597-610. 1999.
2 .Evian, C.J., Karateew, E.D., Rosenberg, E.S. Periodontal soft tissue considerations for anterior esthetics. J. Esthetic Dent 9:68-75. 1997.
For which of the following would you consider the use of an implant-supported restoration for a missing maxillary lateral incisor?
1. Normal wound healing capacity
2. Intact neighbouring teeth
3. Malaligned abutment teeth
4. Diastemas between the incisors
A. 1, 2, 3
B. 1 and 3
C. 2 and 4
D. 4 only
E. All of the above
Although there are several options available for the replacement of missing teeth in the anterior maxilla, a fundamental demand in all situations is aesthetics. All of the above criteria would make an implant supported restoration the treatment of choice.
Normal wound healing is a necessary component for a satisfactory implant outcome. Intact neighbouring teeth suggest that an implant is a more conservative approach to prosthetic replacement. Sacrifice of healthy tooth tissue is not required as it would be for fixed bridgework and, when abutment teeth are malaligned, the path of insertion for a bridge can be difficult or even impossible.
For optimum aesthetics, the presence of diastemas may preclude use of fixed bridgework. An implant can overcome these difficulties. Ideally, implant position should be determined primarily by the planned future prosthesis and not by local bone anatomy alone. As the implant should represent the apical extension of the prosthetic superstructure and not the opposite, the term “restoration driven” rather than “bone driven” implant placement becomes the necessary approach. This implies a precise three-dimensional implant positioning permitting appropriate emergence profile. If an optimum stable aesthetic and functional result has to be achieved, lateral bone augmentation procedures, as well as soft tissue grafting, may be required. In all of these choices, the patient’s needs, expectations, general health condition, as well as the socio-economic profile require to be taken into account for a satisfactory treatment outcome.
– Belser, U.C., Buser, D., Hess, D., et al. Aesthetic implant restorations in partially edentulous patients-a critical appraisal. Periodontology 2000, 17:132-150, 1998.
The mother of a 2-year-old draws attention to the grey-white marks on the child’s teeth. You diagnose this as fluorosis. She asks if the permanent teeth will also be affected. You would
A. tell her the permanent teeth cannot be affected.
B. advise her investigation is not necessary.
C. suggest risk to the permanent dentition is high.
D. review and/or modify the child’s source of fluoride.
A major study by Milsom (1996) showed that primary tooth fluorosis was only weakly predictive of fluorosis in the permanent dentition. It should be noted that while fluorosis of both dentitions share a fundamental etiology, i.e., excessive fluoride ingestion during tooth formation, the specific sources of fluoride ingested during formation of primary teeth may be quite different from those during permanent tooth development.
The primary dentition is thought to be completely formed before the end of the first year of life, whilst the critical period for fluorosis development in the permanent central incisors, for example, is estimated at 22-25 months of age.
From a practical standpoint, any fluorosis detected in a 2-year-old must prompt careful review of the child’s past exposure to fluoride, as well as current fluoride practices. However, at this age, intervention based on detection of primary tooth fluorosis is liable to be too late to prevent fluorosis developing in the permanent central incisors or most other permanent teeth.
The clinician, on detection of fluorosis of the deciduous teeth, should neither overlook nor ignore the finding. Instead, it must raise an awareness of possible increased risk in the permanent dentition, initiate a review, and even modify the individual child’s intake of fluoride to reduce risk.
1. Warren, J.J., Kanellis, M.J., Levy, S.M. Fluorosis of the primary dentition: what does it mean for the permanent teeth? JADA 130: 347-356, 1999
2. The Oral Care Report Vol. 5, No. 4, 1995 Ed. G. Nikiforuk.
Answers for March 2001 SLSA questions:
9. E 10. B 11. A 12. E