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Eye protection for dentists
Light Curing Eye protection for dentists Background.—Dental amalgam is being phased out for restoring dental caries and replaced by adhesive materials. Most of these newer materials contain photoinitiators that are set by exposure to curing lights, usually light-emitting diode (LED) based curing lights. Dentists are therefore exposed to the blue light from curing lights, which can cause eye damage. The risk depends on the lamp emission and radiative geometry, exposure time, degree to which the light is reflected, and use of adequate eye protective wear. Safety is a paramount concern in the dental office, yet many dentists do not routinely wear any personal eye protection when light-cured restorations are placed. A survey was done of Norwegian dentists to assess their exposure to curing light and whether any curing procedure times exceed the recommended radiation limit values. Dentists’ knowledge about the practical use and technical features of curing lights, maintenance requirements, and personal eye protection devices was also evaluated. Methods.—In 2015 a pre-coded questionnaire was delivered electronically to the 1313 dentists in the Public Dental Service (PDS) in Norway. Response rate was 55.8%. Of these participants the ages ranged from 25 to 77 years (mean 42 years), most were women (69.6%), and they were nearly equally divided between small dental practices having 1 to 3 dentists (45.8%) and large dental practices having more than 3 dentists (54.2%). Results.—The reported percentage of the working day spent placing restorations ranged from 10% to 100%, with an average of 57.5%. Most dentists light-cured a normal layer of resin composite for 20 to 29 seconds, with the longest time about 100 times higher than the shortest time. The 31 dentists reporting the highest irradiance for their curing lights cured a normal layer of composite for a mean of 28 seconds. The estimated light dose needed to cure one layer of composite differed significantly, with the highest 15 times the lowest value. Estimated light dose was in the lower part of the range required for sufficient curing. Assessment of the risk of having reflected blue light affecting the dentist’s eyes showed that mean curing time was close to the maximum permissible exposure time for the two lowest irradiance ranges, but exceeded that maximum when curing lights with greater than 2000
mW/cm2 irradiance were used. The dentists who placed the greatest mean number of restorations were exposed to curing light an average of 3 times longer than the mean of all dentists, causing the maximum dose to be exceeded regardless of the curing light irradiance. Maximum permissible exposure time is theoretically exceeded after 34 to 38 layers are cured using lights whose irradiance is in the range of 1000 to 2000 mW/cm2 at a mean curing time of 27 seconds for a single layer. Just 18 cured layers will exceed the maximum when the curing light’s irradiance is 2000 mW/cm2 or greater. Nearly a third of the dentists used inadequate eye protection against blue light. The options reported included no eye protection (1.7%), looking away (7.7%), and relying on the protection shield mounted to the curing light (19.7%). A separate hand-held shield was used by 63.4% of the dentists and protection eyewear by 7.5%; both of these were considered adequate eye protection. Young dentists were significantly more likely to use adequate eye protection than older dentists. Mean daily exposure time to the curing light did not differ between those who did and did not wear adequate eye protection. Restorative material manufacturer’s recommendations were the trusted source of information regarding curing time for 60.9% of the dentists, with others reporting recommendations from dental schools, from the makers of the curing lights, and from their dental clinic guidelines. Among dentists who did not know the age and irradiance of their curing lights, significantly more followed the recommendations from dental schools when compared to the rest of the dentists. Knowledge related to the curing light was lacking among many dentists. Most (78.3%) did not know the irradiance value of their curing lights. A significantly higher percentage of dentists who did not know the irradiance value also did not check the device regularly compared to dentists who knew the device’s irradiance. Nearly 15% had no routine maintenance scheduled for the curing lights, but 36.2% said it was included in the service of the dental unit. Twenty-six percent of the dentists performed visual checks of the lamp’s lens or light guide for scratches, spots, or foreign bodies, and 46.8% used a curing light meter regularly to monitor the lamp’s irradiance. Dentists with new curing lights were significantly less likely to check their device regularly than dentists with a curing light older than 5 years. Although about 25% of the dentists didn’t know
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Issue 5
2017
289
when the curing light had been purchased, the rest reported their light’s mean age as 3.8 years (range 1 to 10 years). Conclusions.—This survey of Norwegian dentists revealed a knowledge gap and poor use of protective eye wear when using curing lights to set resin composite restorations. As a result, many are exposed to levels of irradiance higher than is recommended, which may lead to eye damage.
lights, which can cause harm to the dentist’s eyes if protective gear isn’t worn. Dentists should be aware of the technical specifications of all their valuable equipment, as well as the date purchased. Regular maintenance is required and should be a scheduled part of the dental unit maintenance plan.
Kopperud SE, Rukke NV, Kopperud HM, et al: Light curing procedures – performance, knowledge level and safety awareness among dentists. J Dent 58:67-73, 2017
Clinical Significance.—All dental operators should observe safety precautions when using the tools of their trade. This includes curing
Reprints available from EM Bruzell, Nordic Inst of Dental Materials (NIOM), Sognsveien 70a, NO-0855 Oslo, Norway; e-mail: [email protected]
Malpractice Mandibular third molar extraction complications Background.—The most common complications related to third molar removal are alveolitis, delayed healing, and inferior alveolar nerve (IAN) damage. Nerve injury may be infrequent but it is the major reason for litigation, particularly when the injury involves the IAN or lingual nerve (LN). Although there was hope that the number of nerve injuries could be reduced with preoperative conebeam computed tomography (CBCT), no evidence supports this reduction. The Finnish Patient Insurance Centre (FPIC) files were analyzed to identify areas that may lead to a reduction in complications associated with third molar extraction. Methods.—The FPIC files include all malpractice claims for compensation for patients in Finland. They were searched over a 14-year period, which identified 852 patient cases related to tooth extractions (1009 teeth). Individual cases could involve more than one tooth. The date a case was decided, the tooth or teeth involved, the type of surgery performed, the diagnosis of the specific injury, and the FPIC decision on the case were all evaluated. Results.—Sixty-six percent of the teeth involved were third molars, and 90% of these were located in the mandible. The first and second molars accounted for the second and third largest groups of claims, and the majority of these were also in the mandible.
290
Dental Abstracts
The most common reason for the claim was operative extraction, then ordinary extraction and apicoectomy of a single-rooted tooth. Removal of a third molar was more likely to involve operative extraction than removal of other teeth. Ordinary extraction was more common for other teeth than for third molars. Injury of the LN was responsible for 23% of the claims, injury of the IAN for 18%, and infection for 14%. Among the other reasons for claims were maxillary sinus perforation, damage to neighboring teeth, root fragment remnant, alveolar or jaw bone fracture, TMJ problems, and burns or scarring. Taken together, these other reasons accounted for just 10% of all cases. Individuals could also have more than one diagnosis in a claim. Patients received compensation based on treatment injury and infection injury. Patients were more often granted compensation for cases involving third molars than for those involving any other teeth. Conclusions.—Of the malpractice claims related to tooth extractions, most involved mandibular third molars and the operative extraction of a tooth. Thus removing a mandibular third molar presents a significant risk for complications compared to removing other teeth. In addition, nerve injury is a common complication seen in these cases, especially LN injury, but can be avoided when an
mW/cm2 irradiance were used. The dentists who placed the greatest mean number of restorations were exposed to curing light an average of 3 times longer than the mean of all dentists, causing the maximum dose to be exceeded regardless of the curing light irradiance. Maximum permissible exposure time is theoretically exceeded after 34 to 38 layers are cured using lights whose irradiance is in the range of 1000 to 2000 mW/cm2 at a mean curing time of 27 seconds for a single layer. Just 18 cured layers will exceed the maximum when the curing light’s irradiance is 2000 mW/cm2 or greater. Nearly a third of the dentists used inadequate eye protection against blue light. The options reported included no eye protection (1.7%), looking away (7.7%), and relying on the protection shield mounted to the curing light (19.7%). A separate hand-held shield was used by 63.4% of the dentists and protection eyewear by 7.5%; both of these were considered adequate eye protection. Young dentists were significantly more likely to use adequate eye protection than older dentists. Mean daily exposure time to the curing light did not differ between those who did and did not wear adequate eye protection. Restorative material manufacturer’s recommendations were the trusted source of information regarding curing time for 60.9% of the dentists, with others reporting recommendations from dental schools, from the makers of the curing lights, and from their dental clinic guidelines. Among dentists who did not know the age and irradiance of their curing lights, significantly more followed the recommendations from dental schools when compared to the rest of the dentists. Knowledge related to the curing light was lacking among many dentists. Most (78.3%) did not know the irradiance value of their curing lights. A significantly higher percentage of dentists who did not know the irradiance value also did not check the device regularly compared to dentists who knew the device’s irradiance. Nearly 15% had no routine maintenance scheduled for the curing lights, but 36.2% said it was included in the service of the dental unit. Twenty-six percent of the dentists performed visual checks of the lamp’s lens or light guide for scratches, spots, or foreign bodies, and 46.8% used a curing light meter regularly to monitor the lamp’s irradiance. Dentists with new curing lights were significantly less likely to check their device regularly than dentists with a curing light older than 5 years. Although about 25% of the dentists didn’t know
Volume 62
Issue 5
2017
289
when the curing light had been purchased, the rest reported their light’s mean age as 3.8 years (range 1 to 10 years). Conclusions.—This survey of Norwegian dentists revealed a knowledge gap and poor use of protective eye wear when using curing lights to set resin composite restorations. As a result, many are exposed to levels of irradiance higher than is recommended, which may lead to eye damage.
lights, which can cause harm to the dentist’s eyes if protective gear isn’t worn. Dentists should be aware of the technical specifications of all their valuable equipment, as well as the date purchased. Regular maintenance is required and should be a scheduled part of the dental unit maintenance plan.
Kopperud SE, Rukke NV, Kopperud HM, et al: Light curing procedures – performance, knowledge level and safety awareness among dentists. J Dent 58:67-73, 2017
Clinical Significance.—All dental operators should observe safety precautions when using the tools of their trade. This includes curing
Reprints available from EM Bruzell, Nordic Inst of Dental Materials (NIOM), Sognsveien 70a, NO-0855 Oslo, Norway; e-mail: [email protected]
Malpractice Mandibular third molar extraction complications Background.—The most common complications related to third molar removal are alveolitis, delayed healing, and inferior alveolar nerve (IAN) damage. Nerve injury may be infrequent but it is the major reason for litigation, particularly when the injury involves the IAN or lingual nerve (LN). Although there was hope that the number of nerve injuries could be reduced with preoperative conebeam computed tomography (CBCT), no evidence supports this reduction. The Finnish Patient Insurance Centre (FPIC) files were analyzed to identify areas that may lead to a reduction in complications associated with third molar extraction. Methods.—The FPIC files include all malpractice claims for compensation for patients in Finland. They were searched over a 14-year period, which identified 852 patient cases related to tooth extractions (1009 teeth). Individual cases could involve more than one tooth. The date a case was decided, the tooth or teeth involved, the type of surgery performed, the diagnosis of the specific injury, and the FPIC decision on the case were all evaluated. Results.—Sixty-six percent of the teeth involved were third molars, and 90% of these were located in the mandible. The first and second molars accounted for the second and third largest groups of claims, and the majority of these were also in the mandible.
290
Dental Abstracts
The most common reason for the claim was operative extraction, then ordinary extraction and apicoectomy of a single-rooted tooth. Removal of a third molar was more likely to involve operative extraction than removal of other teeth. Ordinary extraction was more common for other teeth than for third molars. Injury of the LN was responsible for 23% of the claims, injury of the IAN for 18%, and infection for 14%. Among the other reasons for claims were maxillary sinus perforation, damage to neighboring teeth, root fragment remnant, alveolar or jaw bone fracture, TMJ problems, and burns or scarring. Taken together, these other reasons accounted for just 10% of all cases. Individuals could also have more than one diagnosis in a claim. Patients received compensation based on treatment injury and infection injury. Patients were more often granted compensation for cases involving third molars than for those involving any other teeth. Conclusions.—Of the malpractice claims related to tooth extractions, most involved mandibular third molars and the operative extraction of a tooth. Thus removing a mandibular third molar presents a significant risk for complications compared to removing other teeth. In addition, nerve injury is a common complication seen in these cases, especially LN injury, but can be avoided when an