Complying with the Occupational Safety and Health Administration: guidelines for the dental office

This article outlines Occupational Safety and Health Administration (OSHA) guidelines for maintaining a safe dental practice workplace and covers requirements, such as education and protection for dental health care personnel. OSHA regulations aim to reduce exposure to blood-borne pathogens. Environmental infection control in dental offices and operatories is the goal of enforcement of OSHA codes of practice. Universal precautions reduce the risk for infectious disease. OSHA has a mandate to protect workers in the United States from potential workplace injuries. OSHA standards are available through online and print publications and owners of dental practices must meet OSHA standards for the workplace.     

Development of the Occupational Safety and Health Administration''s Proposed Standard to Protect Workers from Contracting Bloodborne Diseases in the Workplace

The Occupational Safety and Health Administration (OSHA) is in the process of developing a health standard to protect workers by reducing occupational exposure to hepatitis B virus, human immunodeficiency virus, and other bloodborne pathogens. This article reviews the history of the standard, the steps involved in OSHA standard development, and--most specifically--how the dental professional can participate in this process.     

OSHA 2000: a review of compliance issues

The California Occupational Safety and Health Administration is responsible for enforcing worker safety regulations in the state of California. The infection control regulation, while the best known to dentists, is only one of many that affect every dental practice. The past two years have brought significant changes to Cal/OSHA rules. This paper reviews some of the current regulations that apply to dental offices.     

Needlestick injuries in dentistry: Time to revisit

BackgroundBlood-borne pathogens (BBPs) are infectious microorganisms that are found in human blood and can cause diseases in humans. Health care workers such as physicians, surgeons, nurses, dentists, dental students, dental assistants, laboratory technicians, personnel handling infectious waste, and other health care employees are at increased risk of exposure to these pathogens. Percutaneous injuries from needles or other sharp objects are the major sources of BBPs in the workplace. Needlestick injuries (NSIs) have the most potential to transmit and have the easiest mode of transmission of BBPs.Types of Studies ReviewedThe authors searched electronic databases (PubMed, Web of Science, Google Scholar, Scopus, Embase, MEDLINE-Ovid) for studies and articles focused on the various aspects of NSIs, their possible causes, prevention, and management protocols.ResultsThere is a lack of literature on the global prevalence of NSIs among dental practitioners and underreporting of NSIs by clinicians. The authors also found that dental students and inexperienced practitioners were the most vulnerable. They found apparent inconsistencies in guidelines and recommendations from various regulatory and statutory agencies in charge of limiting and managing NSIs.ConclusionThe most significant occupational risks for health care workers globally are NSIs. Dentists are recognized as one of the high-risk groups for exposure to NSIs. Although the reporting rate was noticeably low, the frequency of NSIs among dental students was alarmingly high.Practical ImplicationsAppropriate and succinct training of dental health care workers is crucial for prevention and management of NSIs. It is recommended that dentists familiarize themselves with recommendations from such agencies and organizations as the Center for Disease Control and Prevention, Occupational Safety and Health Administration, and American Dental Association.     

Advances in light curing units and curing techniques: a literature review.

There exists a constant need for a dental curing light that works reliably and conveniently in the general practitioner's office and can be used effectively for all the different curing procedures. Due to the need for improved physical properties of resin based composites (RBCs) and less stress at the marginal interface, light curing units (LCUs) experienced significant advances in the past years. The dental industry has focused on reducing the curing time by developing higher intensity curing lights and by altering the resin composition and photo-initiator concentration. As a result the dentist can now choose from a vast variety of curing lights, light intensities and curing methods. This article presents a review of the advances in light curing units and curing techniques, as well as the scientific principles that guided past developments and that will influence future advances.     

Effects of curing lights on human gingival epithelial cell proliferation

BackgroundLight-emitting diode (LED) and quartz-tungsten-halogen (QTH) curing lights are used commonly in clinics. The aim of this study was to assess the effect of these lights on the proliferation of human gingival epithelial cells.MethodsSmulow-Glickman (S-G) cells were exposed to a VALO LED (Ultradent) or an XL3000 QTH (3M ESPE) light at 1 millimeter or 6 mm distance for 18, 39, 60, and 120 seconds. Untreated and Triton X-100 treated cells were used as controls. At 24, 48, and 72 hours after light exposure, cell proliferation was evaluated via a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.ResultsThe authors first evaluated the performances of these 2 lights. Both LED and QTH lights generated heat. The LED light generated less heat than the QTH light and could save approximately two-thirds of the curing time. When used for 18 seconds at a 6 mm distance, the LED light did not inhibit the proliferation of S-G cells. However, if the exposure time was longer (for example, 39, 60, or 120 seconds), the LED light inhibited cell proliferation. The inhibitory effect increased when the exposure time was increased to 39, 60, or 120 seconds. The QTH light did not inhibit S-G cell proliferation if the exposure time was less than 120 seconds.ConclusionsProlonged exposure to a blue curing light (both LED and QTH) inhibits the proliferation of gingival epithelial cells and may cause damages to oral soft tissues.Practical ImplicationsIn dental practices, a balance should be struck in consideration of curing time not only to cure the composites completely but also to minimize unnecessarily prolonged light exposure.     

International employment in clinical practice: influencing factors for the dental hygienist

Purpose: To assess demographics, job characteristics, geographical regions, resources and commitment, which influence dental hygienists seeking international clinical practice employment opportunities. Methods: Questionnaires were mailed to a convenience sample of members of the Dental Hygienists’ Association of the City of New York. Statistical analyses were conducted and frequency distributions and relationships between variables were calculated. Results: Seventy‐two percent of respondents reported that they are or may be interested in working overseas. Italy and Spain (67%) were the regions of most interest. Salary (65%) was cited as the most influencing factor in selection, whereas non‐compliance with the equivalency to Occupational Safety and Health Administration standards (74%) was the most frequently perceived barrier. Multiple language fluency was statistically significant (0.003) regarding interest in overseas employment. Conclusion: Policy makers, employers and educators need to be aware of these findings should recruitment be a possibility to render urgently needed oral hygiene care in regions where there is a perceived shortage of dental hygienists.     

OSHA bloodborne pathogens rule--revisions and clarifications

Recent revisions to the Occupational Safety and Health Administration's Bloodborne Pathogens Rule have clarified requirements for record keeping and engineered sharps injury protection devices. It is important for dental workers, and especially dentists who are employers, to be aware of the changes in the regulatory language and be prepared to modify existing programs to meet these new demands. This article provides an overview of the 2001 Bloodborne Pathogens Rule with an emphasis on the impact on dental offices.     

Eye safety practices in U.S. dental school restorative clinics, 2006

This study was conducted to determine how much progress U.S. dental schools have made in providing eye protection during restorative (adult operative and fixed prosthodontic) procedures since a 1979 survey. A seven-question survey was placed at a website, and fifty-five different U.S. dental schools were asked to complete the survey. Thirty-one schools responded (56 percent). Eighty-four percent of schools had safety glasses available for patients, but only 77 percent required usage during restorative procedures. Similarly, while 87 percent of schools required dental students working in restorative clinics to wear safety glasses, just 73 percent enforced the policy. Additionally, 84 percent provided blue light protection on curing lights and required students to wear eye protection while doing lab procedures. Compared to the 1979 survey, considerable progress has been made over the last twenty-seven years in protecting dental school patients and students from ocular injuries. Because one would hope to have 100 percent compliance on this issue, there is room for improvement in promoting patient eye safety and teaching good habits to dental students.     

Potential health and environmental issues of mercury-contaminated amalgamators

BACKGROUND: Dental amalgamators may become contaminated internally with metallic mercury. This contamination may result from mercury leakage from capsules during trituration or from the long-term accrual from microscopic exterior contaminants that result from the industrial assembly process. The potential health risk to dental personnel from this contamination is unknown. METHODS: The authors assessed used amalgamators from the federal service inventory for the amounts of mercury vapor levels, as well as the visual presence of mercury contamination. They evaluated these amalgamators for potential mercury vapor health risk, using established National Institute for Occupational Safety and Health methods and American Conference of Governmental Industrial Hygienists standards. RESULTS: Ten of the 11 amalgamators assessed had measurable mercury vapor levels. Four amalgamators were found to have internal static mercury vapor levels above Occupational Safety and Health Administration ceiling limit thresholds. During a simulated worst-case clinical use protocol, the authors found that no amalgamators produced mercury vapor in the breathing space of dental personnel that exceeded established time-weighted federal mercury vapor limits. CONCLUSIONS: Amalgamators may be contaminated internally with metallic mercury. Although the authors detected mercury vapor from these units during aggressive, simulated clinical use, dilution factors combined with room air exchange were found to keep health risks below established federal safety thresholds. CLINICAL IMPLICATIONS: Dental personnel should be aware that amalgamators may be contaminated with mercury and produce minute amounts of mercury vapor. These contaminated amalgamators may require disposal as environmentally hazardous waste.     

Dental composite depth of cure with halogen and blue light emitting diode technology.

OBJECTIVES: To test the hypothesis that a blue light emitting diode (LED) light curing unit (LCU) can produce an equal dental composite depth of cure to a halogen LCU adjusted to give an irradiance of 300 mWcm-2 and to characterise the LCU's light outputs. MATERIALS AND METHODS: Depth of cure for three popular composites was determined using a penetrometer. The Student's t test was used to analyse the depth of cure results. A power meter and a spectrometer measured the light output. RESULTS: The spectral distribution of the LCUs differed strongly. The irradiance for the LED and halogen LCUs were 290 mWcm-2 and 455 mWcm-2, when calculated from the scientific power meter measurements. The LED LCU cured all three dental composites to a significantly greater (P < 0.05) depth than the halogen LCU. CONCLUSIONS: An LED LCU with an irradiance 64% of a halogen LCU achieved a significantly greater depth of cure. The LCU's spectral distribution of emitted light should be considered in addition to irradiance as a performance indicator. LED LCUs may have a potential for use in dental practice because their performance does not significantly reduce with time as do conventional halogen LCUs.     

Legal implications of OSHA and CDC regulations

The epidemic of acquired immunodeficiency syndrome has initiated a number of regulations, at both the federal and state level, that impact directly on the practice of dentistry. During the past 5 to 6 years, guidelines have been published that specifically and generally state those procedures which should be implemented in the dental practice with regard to infectious disease control. However, confusion remains regarding these procedural guidelines and the differences that exist between municipal, state, and federal regulations. The ensuing discussion (1) reviews the historical background of the guidelines, (2) reflects on the current Occupational Safety and Health Administration guidelines as they relate to the dental practice, (3) summarizes the role of the regulatory agencies, (4) discusses federal and state statutes that have impact on the dental practitioner, and (5) describes the possible legal implications that these regulations may have on the dental practice.     

Fibrous ceramic aluminum silicate as an alternative to asbestos liners

The actual risk to those exposed to asbestos fibers in the dental laboratory is presently unknown. The ADA Council on Dental Materials and Devices and ADA Council on Dental Therapeutics have received encouragement from the National Institute for Occupational Safety and Health to conduct further studies, including monitoring airborne asbestos in dental laboratories.⁴⁶ It has been suggested that no really safe threshold limit exists for airborne asbestos fibers.^47–49 Low level asbestos exposure has been implicated in numerous serious diseases.^8,11 Exposures as brief as 1 month have produced disease many years later.^7,12Numerous researchers^23,28,50,51 have advocated the use of a safer material. Casting ring liners composed of currently available fibrous ceramic aluminum silicate are technically adequate substitutes for asbestos.¹⁵     

Status of scrap (recyclable) dental amalgams as environmental health hazards or toxic substances

This article presents information garnered after an investigation by the Environmental Protection Agency in 1987 of dentists and others who had sold scrap dental amalgam to refiners who had "arranged for the disposal or treatment ... of hazardous substances," and were responsible for adverse consequences associated with their subsequent management and refining. Information about the health hazard status of scrap dental amalgams was obtained by: interviews with toxicologists, review of published lists of toxic and hazardous materials, and survey of biomedical publications (1977 through 1987) concerning toxicity or health hazards associated with dental amalgams. The conclusions were that scrap dental amalgam is not: a waste substance to be disposed of, but is a product of commercial value; identified or regulated by the Environmental Protection Agency, the Occupational Safety and Health Administration, the Department of Transportation, the Food and Drug Administration, the National Institute of Occupational Safety and Health, the US Public Health Service, or the Centers for Disease Control as an environmental health hazard or toxic substance; identified by toxicologists and persons responsible for solid waste regulation as a toxic substance or environmental health hazard; nor proved by scientific study to be toxic or hazardous in the manner and form in which it is collected and stored by dentists and subsequently sold to metal refiners.     

Standard and Transmission-Based Precautions: An Update for Dentistry

BackgroundStandard Precautions are the foundation of all infection control programs and include infection control practices that apply to all patients and situations regardless of whether the infection status is suspected, confirmed or unknown.MethodsThe author reviewed Standard Precautions, including two new elements introduced by the Centers for Disease Control and Prevention in 2007: safe injection practices and respiratory hygiene and cough etiquette. Standard Precautions sometimes are referred to as the first tier of precautions because for some diseases and circumstances, transmission cannot be interrupted completely with Standard Precautions alone and it is necessary to use second-tier Transmission-Based Precautions. The author reviewed the three categories of Transmission-Based Precautions—Airborne, Droplet and Contact—with an emphasis on their use in dental health care outpatient settings.Conclusions and Clinical ImplicationsDental health care personnel (DHCP) should update their infection control programs to ensure that safe injection practices and respiratory hygiene and cough etiquette measures are used routinely. In addition, with the emergence of new pathogens, re-emergence of variant organisms and more patients seeking care in ambulatory care facilities, DHCP need to be aware of additional measures to take when treating patients in their offices who are actively infected with certain organisms to protect fully other patients, their staff members and themselves.     

Localised irradiance distribution found in dental light curing units

Objective

To measure the localised irradiance and wavelength distributions from dental light curing units (LCUs) and establish a method to characterise their output.

Methods

Using a laboratory grade integrating sphere spectrometer system (Labsphere and Ocean Optics) the power, irradiance, and spectral emission were measured at the light tips of four LCUs: one plasma-arc (PAC) unit, one single peak blue light-emitting diode (blue-LED) unit, and two polywave LED (poly-LED) units. A beam profiler camera (Ophir Spiricon) was used to record the localised irradiance across the face of the light tips. The irradiance-calibrated beam profile images were then divided into 45 squares, each 1 mm². Each square contained the irradiance information received from approximately 3200 pixels. The mean irradiance value within each square was calculated, and the distribution of irradiance values among these 45 squares across the tip-ends was examined. Additionally, the spectral emission was recorded at various regions across each light tip using the integrating sphere with a 4-mm diameter entrance aperture.

Results

The localised irradiance distribution was inhomogeneous in all four lights. The irradiance distribution was most uniformly distributed across the PAC tip. Both the irradiance and spectral emission from the poly-LED units were very unevenly distributed.

Conclusions

Reporting a single irradiance value or a single spectral range to describe the output from a curing light is both imprecise and inappropriate. Instead, an image of both the irradiance distribution and the distribution of the spectral emission across the light tip should be provided.

Clinical significance

The localised beam irradiance profile at the tip of dental LCUs is not uniform. Poly-LED units may deliver spectrally inhomogeneous irradiance profiles. Depending on the photoinitiator used in the RBC and the orientation of the LCU over the tooth, this non-uniformity may cause inadequate and inhomogeneous resin polymerisation, leading to poor physical properties, and premature failure of the restoration.     

Stability and reproducibility of radiometric properties of light curing units (LCUs). Part II: LED LCUs

The present work is the second part of a study on the stability and reproducibility of the energy and spectral emission of some light curing units (LCUs). In this part, Part II, LED LCUs were investigated. Results revealed that these devices presented high stability and reproducibility in terms of their spectral emission, with values of VAF (variance accounting for) coefficient calculated from the Cauchy-Schwarz inequality all close to 100%. With respect to energy stability, the LED LCUs presented energy stability except for the third-generation LED LCUs which have several LEDs. For these devices, the law of reciprocity was not fulfilled as irradiance was not constant over exposure time. This result should be taken into account both in works examining the polymerization kinetics of dental materials as well as when these LED LCUs are used in clinical practice.     

Optical power outputs,spectra and dental composite depths of cure,obtained with blue light emitting diode (LED) and halogen light curing units (LCUs)

OBJECTIVE: To test the hypothesis that a prototype LED light curing unit, (LCU), a commercial LED LCU and a halogen LCU achieve similar cure depths, using two shades of a camphorquinone photoinitiated dental composite. To measure the LCUs' outputs and the frequency of the LED LCU's pulsed light, using a blue LED array as a photodetector. DESIGN: Cure depth and light output characterisation to compare the LCUs. SETTING: An in vitro laboratory study conducted in the UK. MATERIALS AND METHODS: The LCUs cured A2 and A4 composite shades. A penetrometer measured the depth of cure. Analysis was by one-way ANOVA, two-way univariate ANOVA and Fisher's LSD test with a 95% confidence interval. A power meter and spectrograph characterised the LCUs' emissions. A blue LED array measured the pulsed light frequency from an LED LCU. RESULTS: Statistically significant different LCU irradiances (119 mW/cm2 to 851 mW/cm2) and cure depths (3.90 mm SD +/- 0.08 to 6.68 mm SD +/- 0.07) were achieved. Composite shade affected cure depth. A blue LED array detected pulsed light at 12 Hz from the commercial LED LCU. CONCLUSIONS: The prototype LED LCU achieved a greater or equal depth of cure when compared with the commercial LCUs. LEDs may have a potential in dentistry for light detection as well as emission.     

The effect of disposable infection control barriers and physical damage on the power output of light curing units and light curing tips

This study investigated the effects that disposable infection control barriers and physical damage through use had on the power output from dental light curing units (LCUs) and light curing tips (LCTs). Five disposable infection control barriers were tested on a number of LCUs and LCTs. Testing involved the repeated measurement of power output of LCUs and LCTs on a radiometer. Two of the barriers tested caused statistically significant reductions in the mean light output intensity when compared to the no barrier control groups. One barrier type reduced the power output by 30 to 40%. It was also noted that physical damage to the LCTs affected power output by between 20 and 30%, which was then further reduced by the disposable barrier. This study showed that three of the five disposable infection control barriers had little effect on the overall efficiency of the power output of the LCUs. It also showed that physical damage to LCUs and LCTs can affect power output significantly. Infection control measures should be carefully considered before use to avoid undue effects on power output delivered from the LCUs/LCTs to ensure that the degree of polymerisation within the resin-based composite and curing efficiency are not affected unduly.     

A Researcher''s View

The Food and Drug Administration (FDA), by ensuring that the health care products used by Americans are both safe and effective, provides an essential regulatory function. With respect to the regulation of dental drug products, this researcher perceives that the FDA has not changed or modified its position on a number of issues to reflect new scientific information. Reasons for this inflexibility include the size and ponderousness of the agency, inadequate staff with dental expertise, and a failure to keep current with new dental research findings. The FDA must solve these problems if it wishes to regulate intelligently. The acceptance and certification programs of the American Dental Association ensure that products offered to the profession and the public that bear its seal of acceptance are safe and effective. The ADA's Council on Dental Therapeutics has a long history of staying current on issues in dental research and public health and regularly seeks consultation from eminently qualified experts. Overall, it has done an excellent job over the years in conducting an important voluntary regulatory program. Both the FDA and the ADA benefit and help protect the oral health of the public.