- Email: [email protected]
Changes produced by oral appliance therapy
most common sterilization method used. The 2 decontamination methods used most frequently were manual cleaning and autoclaving or manual cleaning, ultrasonic cleaning, and autoclaving. The results in terms of residual contamination of the files varied widely, even though the same methods of decontamination were used. Discussion.—Endodontic files were shown to be routinely contaminated with tissue debris after their reprocessing. Thus, they carry a potential risk for transmitting infection. The disinfection processes yielded varying results, making such cleansing both unreliable and unpredictable. Seventy-five percent of the tested files showed visual contamination after processing. However, all the files were accepted by the practitioners as ready for repeat use. Some manufacturers consider these files as single-use devices, and others recommend sterilization procedures not currently in common use. The laboratory findings suggest that endodontic files should be viewed as single-use devices to avoid potential contamination. The study did not include the number of times each file had been used, nor how often the instruments were decontaminated. It is possible
that a build-up of contaminants develops with repeated cycles of use and cleansing. The heat used for sterilization may then fix any residual material onto the file surface.
Clinical Significance.—Examination of previously used endodontic files disclosed that no cleaning protocol consistently eliminated visually discernible, blood-tainted debris. Additionally, no consistency was found between different practices that used the same protocol. Effective cleaning for the reuse of endodontic instruments is unpredictable. Used instruments should be discarded.
Letters S, Smith AJ, McHugh S, et al: A study of visual and blood contamination on reprocessed endodontic files from general dental practice. Br Dent J 199:522-525, 2005 Reprints available from A Smith, Infection Research Group, Level 9, Univ of Glasgow Dental School, 378 Sauchiehall St, Glasgow G2 3JZ; e-mail: [email protected]
Occlusion Changes produced by oral appliance therapy Background.—Oral appliance (OA) therapy has proved effective for patients with primary snoring and mild apnea and those with moderate-to-severe obstructive sleep apnea. With this therapy, the upper airway enlarges, improving its stability. Side effects of OA therapy include decreased overjet and overbite and a mesial shift of the mandible. Whether additional changes in the occlusion and dental arches occur with longer term therapy was evaluated with the use of study models. Methods.—Stone casts were obtained in centric occlusion for 70 patients before OA placement. Follow-up casts
296 Dental Abstracts
were then taken after an average of 7.4 years of OA therapy, and the casts were compared visually by 5 orthodontists. Results.—Initially, 48 patients were Class I, 10 Class II Division 1, 10 Class II Division 2, and 2 Class III. A change in dental arch or occlusion was observed in 85.7% of the patients. For 41.4% of patients, the change was favorable and for 44.3% it was unfavorable. More of the patients with unfavorable changes were Class I subjects initially. More of the patients with favorable changes were Class II subjects initially. A significant mesial shift of the mandibular canines and molars occurred. The initial overbite and overjet were
significantly smaller for the group with unfavorable changes than for the group with favorable changes. The favorable and unfavorable groups differed significantly in canine mesialization, number of teeth per patient that changed into edge-to-edge or crossbite in the anterior and posterior segments, and number of teeth per patient that changed into an edge-to-edge or posterior open-bite relationship. The initial overbite declined more than 1 mm in 68.6% of patients. The initial overjet declined more than 1 mm in 50% of patients. Overall there were significant changes in the number of interproximal open spaces in both maxilla and mandible and significant increases in intercanine, intermolar, and arch length distances. Patients whose initial overbites were larger and who had Class II Division 1 and Class II Division 2 malocclusions were more likely to have no change or favorable changes. Having a combination of larger initial overjet and more distal mandibular canine relationship was correlated with favorable changes. Those with larger initial overjet developed more favorable changes, decreased mandibular crowding, less change in anterior crossbite, and greater change in extent of overjet. Discussion.—The use of a mandibular advancement appliance for at least 5 years produced significant occlusal changes in the vast majority of these patients. The changes for about half the patients were favorable and those for the other half were unfavorable. A smaller overbite and overjet
initially were associated with unfavorable changes more often than favorable. Unfavorable changes also were more likely in patients with Class I craniofacial characteristics. OA therapy is a lifelong treatment, as obstructive sleep apnea tends to worsen with age. Careful monitoring of the side effects noted in this study is warranted with the use of both cephalometric evaluation and study model analysis.
Clinical Significance.—Because treatment of sleep apnea can be expected to be a longterm affair, it is important to watch for the occlusal changes possible with extended oral appliance therapy. Discussed here is the use of study casts to monitor these changes.
Ribeiro de Almeida F, Lowe AA, Otsuka R, et al: Long-term sequellae of oral appliance therapy in obstructive sleep apnea patients: Part 2. Study-model analysis. Am J Orthod Dentofacial Orthop 129:205213, 2006 Reprints available from FR Almeida, Div of Orthodontics, Dept of Oral Health Sciences, Faculty of Dentistry, Univ of British Columbia, 2199 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3; e-mail: [email protected]
Operative Dentistry Carisolv system for caries removal Background.—The pressure and heat generated during mechanical caries removal and the noise of the handpiece promote sensations of fear and pain in the patient. Sometimes mechanical bur drilling overly prepares healthy dentin, possibly leading to pulp inflammation and/or exposure. Chemomechanical carious dentin removal systems
have been developed to address these problems. The Carisolv system is viewed as 1 of the most effective of these systems and is minimally invasive, removing carious dentin gently and safely without harming sound dental tissues. Disadvantages include longer preparation time, residual carious dentin and bacteria, and lack of a proper clinical
Volume 51 • Issue 5 • 2006 297
that a build-up of contaminants develops with repeated cycles of use and cleansing. The heat used for sterilization may then fix any residual material onto the file surface.
Clinical Significance.—Examination of previously used endodontic files disclosed that no cleaning protocol consistently eliminated visually discernible, blood-tainted debris. Additionally, no consistency was found between different practices that used the same protocol. Effective cleaning for the reuse of endodontic instruments is unpredictable. Used instruments should be discarded.
Letters S, Smith AJ, McHugh S, et al: A study of visual and blood contamination on reprocessed endodontic files from general dental practice. Br Dent J 199:522-525, 2005 Reprints available from A Smith, Infection Research Group, Level 9, Univ of Glasgow Dental School, 378 Sauchiehall St, Glasgow G2 3JZ; e-mail: [email protected]
Occlusion Changes produced by oral appliance therapy Background.—Oral appliance (OA) therapy has proved effective for patients with primary snoring and mild apnea and those with moderate-to-severe obstructive sleep apnea. With this therapy, the upper airway enlarges, improving its stability. Side effects of OA therapy include decreased overjet and overbite and a mesial shift of the mandible. Whether additional changes in the occlusion and dental arches occur with longer term therapy was evaluated with the use of study models. Methods.—Stone casts were obtained in centric occlusion for 70 patients before OA placement. Follow-up casts
296 Dental Abstracts
were then taken after an average of 7.4 years of OA therapy, and the casts were compared visually by 5 orthodontists. Results.—Initially, 48 patients were Class I, 10 Class II Division 1, 10 Class II Division 2, and 2 Class III. A change in dental arch or occlusion was observed in 85.7% of the patients. For 41.4% of patients, the change was favorable and for 44.3% it was unfavorable. More of the patients with unfavorable changes were Class I subjects initially. More of the patients with favorable changes were Class II subjects initially. A significant mesial shift of the mandibular canines and molars occurred. The initial overbite and overjet were
significantly smaller for the group with unfavorable changes than for the group with favorable changes. The favorable and unfavorable groups differed significantly in canine mesialization, number of teeth per patient that changed into edge-to-edge or crossbite in the anterior and posterior segments, and number of teeth per patient that changed into an edge-to-edge or posterior open-bite relationship. The initial overbite declined more than 1 mm in 68.6% of patients. The initial overjet declined more than 1 mm in 50% of patients. Overall there were significant changes in the number of interproximal open spaces in both maxilla and mandible and significant increases in intercanine, intermolar, and arch length distances. Patients whose initial overbites were larger and who had Class II Division 1 and Class II Division 2 malocclusions were more likely to have no change or favorable changes. Having a combination of larger initial overjet and more distal mandibular canine relationship was correlated with favorable changes. Those with larger initial overjet developed more favorable changes, decreased mandibular crowding, less change in anterior crossbite, and greater change in extent of overjet. Discussion.—The use of a mandibular advancement appliance for at least 5 years produced significant occlusal changes in the vast majority of these patients. The changes for about half the patients were favorable and those for the other half were unfavorable. A smaller overbite and overjet
initially were associated with unfavorable changes more often than favorable. Unfavorable changes also were more likely in patients with Class I craniofacial characteristics. OA therapy is a lifelong treatment, as obstructive sleep apnea tends to worsen with age. Careful monitoring of the side effects noted in this study is warranted with the use of both cephalometric evaluation and study model analysis.
Clinical Significance.—Because treatment of sleep apnea can be expected to be a longterm affair, it is important to watch for the occlusal changes possible with extended oral appliance therapy. Discussed here is the use of study casts to monitor these changes.
Ribeiro de Almeida F, Lowe AA, Otsuka R, et al: Long-term sequellae of oral appliance therapy in obstructive sleep apnea patients: Part 2. Study-model analysis. Am J Orthod Dentofacial Orthop 129:205213, 2006 Reprints available from FR Almeida, Div of Orthodontics, Dept of Oral Health Sciences, Faculty of Dentistry, Univ of British Columbia, 2199 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3; e-mail: [email protected]
Operative Dentistry Carisolv system for caries removal Background.—The pressure and heat generated during mechanical caries removal and the noise of the handpiece promote sensations of fear and pain in the patient. Sometimes mechanical bur drilling overly prepares healthy dentin, possibly leading to pulp inflammation and/or exposure. Chemomechanical carious dentin removal systems
have been developed to address these problems. The Carisolv system is viewed as 1 of the most effective of these systems and is minimally invasive, removing carious dentin gently and safely without harming sound dental tissues. Disadvantages include longer preparation time, residual carious dentin and bacteria, and lack of a proper clinical
Volume 51 • Issue 5 • 2006 297