Interest in Dental Hygiene Therapy: a study of dental hygienists in Maine

Introduction

Global access to dental care continues to be a challenge due to the lack of availability and disproportionate distribution of dentists.^1-5 An estimated 47 million residents in the United States (U.S.) are currently living in Dental Health Professional Shortage Areas (D-HPSAs).^1-5 Despite dental caries being a preventable disease, 18% of children aged 5-19 years, 27% of adults aged 20-44 years, and 19% over age 65 in the U.S. were found to have untreated dental caries between the years of 2011-12.⁶ Disparities related to untreated dental caries increased in those aged 65 and over to 41% in Black or African Americans, and 48% in Mexican Americans.⁶ Health disparities have also resulted in Hispanic adults lacking the most in accessing dental care, with 40% of those living below the poverty level having untreated dental caries.⁶ Current dental workforce models are not meeting the needs of all Americans as demonstrated by these statistics.

PEW Charitable Trusts (PEWCT) reports from 2014, identified dentist shortages in the state of Maine, with an estimated 180,000 residents unable to access oral health care due to a lack of dentists in 15 out of 16 counties.⁷ Most of the state, with the exception of the major metropolitan areas of Portland, Augusta, and Bangor, has been designated as Dental Health Professional Shortage Areas (D-HPSAs).⁸ Concerns regarding an insufficient dental workforce in Maine dates back to 2010–11, when the state's dental licensing board reported 92 dentists had either withdrawn or not renewed their expired licenses.⁷ While 96 new dental licenses were issued during that period, the resulting gain of 4 dentists was insufficient to meet the needs of the state's residents.⁷ In 2013, Maine was ranked among the top 12 states having greater than 15% of its residents living in underserved areas due to dental workforce shortages,⁷ and was ranked 6^th in the nation in regards to the percentage of low income children (62.4%) who did not receive dental care in 2011.⁷

Alternative dental workforce models to meet the oral health needs of their respective populations have been developed internationally to address dental workforce shortages, similar to those found in rural areas in the U.S.¹ New Zealand was one of the first countries to develop an alternative workforce model with the introduction of the dental nurse in 1921. The New Zealand dental nurse was created as a response to a dentist shortage and poor oral health; a public health issue that led to high rejection rates for military recruits during World War I.^1,2 The first school for dental nurses was two academic years in length and focused on preventive and restorative care delivered primarily in school-based settings for children up to age 12.^1,2

Approximately 30 developed and developing countries including the United Kingdom, Australia, Canada, Nigeria, Italy, and Costa Rica began to use dental nurses by the 1970's.⁹ Dental nurses were referred to as a dental therapists (DT) during the 1980's and since then, DTs have provided oral care in over 54 countries.^2,3 In some countries, the DT scope of practice requires that the care to be limited to children, however, others allow DTs with additional training to also care for adults.³ New Zealand and Australia, DTs are dually trained as dental hygienists.³ The scope of practice for DTs in most countries includes: preventive services, preparation and placement of amalgam and composite restorations, stainless steel crowns, pulpotomies, and scaling.³ Some countries limit dental care to atraumatic restorative treatment (ART), a minimally invasive care approach that does not require drilling or anesthesia and simple extractions.^{2, 10} Supervision for the dental therapist varies from practicing independently with a collaborative relationship with a dentist, to direct supervision by a dentist.³

The history of midlevel dental providers in the U.S. dates back to 1949, when the Forsyth Dental Infirmary in Boston, Massachusetts obtained permission from the state legislature to conduct a five year research project to train dental hygienists to prepare and fill simple cavities.¹¹ However, the law was repealed the following year due to objections from the dental profession.¹¹ Another attempt was made in 1972 at the Forsyth Center with a grant funded experimental program to teach dental hygienists to administer local anesthesia, and to prepare and place dental restorations.¹² The project was discontinued after two years due to legal action from the Massachusetts Attorney General and pressure from the state board of dental examiners.^{3, 13}

Midlevel dental providers did not emerge again in the U.S. until 2003, when the urgent need to respond to the oral health needs of underserved native Alaskans was identified. Native American Alaskans were sent to New Zealand by their Tribal Health Consortium for training in culturally competent, emergent, and restorative care.³ Care from the Alaska Dental Health Aid Therapists (DHATs) is limited to members of Alaskan tribal communities. The two-year training program was initially established at the University of Washington and is currently affiliated with Iḷisaġvik College, an Alaskan Tribal college and offers a certificate and an associate degree in Dental Health Therapy.^3,14

Following initial education, DHATs complete a preceptorship under the direct supervision of a dentist.¹⁵ Certified DHATs are able to practice under general supervision with the supervising dentist visiting the treatment sites to monitor the standard of preventive, basic restorative, and urgent care provided by DHATs.¹⁵ Re-certification and 24 hours of continuing education are required of the DHAT biannually along with continual evaluation of competency.¹⁵

While the midlevel provider title varies, the scope of practice for Minnesota's advanced dental therapist (ADT), Maine's dental hygiene therapist (DHT) and Vermont's dental therapist (DT) allows for restorative care procedures similar to Alaska's DHAT.^3,4,16,17 However, differences exist in the level of education required, practice requirements and type of supervision, depending on the legislation enacted within each state.^3,4,16,17

In 2009, Minnesota passed legislation to enable two types of dental therapists: a DT educated at the bachelor level and working under the direct supervision of a dentist, and an ADT initially educated as a dental hygienist and completion of dental therapy at the master's degree level.³ The DT bachelor's degree program was discontinued in 2016; currently only the dual degree, masters level ADT program is available at the University of Minnesota School of Dentistry in Minneapolis, and at Metropolitan State University in St. Paul.⁴ ADTs in Minnesota practice under general supervision, in accordance with a collaborative agreement with a dentist specifying the treatment settings, the populations being served, the scope of practice and allowable procedures, case selection criteria, assessment procedures and imaging protocols.³ ADTs also work with low-income, uninsured, and underserved patients, or in dental health professional shortage areas.³

Maine has developed several alternative dental provider models, including the independent practice dental hygienist (IPDH), a specially qualified licensed dental hygienist.¹⁸ IPDHs can deliver preventive dental hygiene treatment without a dentist's supervision, however, licensure is provided only to those who have completed 2,000 hours of clinical practice under the supervision of a dentist.¹⁸ A written practice agreement with a dentist is also required for the IPDH to expose radiographs on patients.¹⁸

Licensed dental hygienists can also be given public health supervision (PHS) status authorizing practice in a public health setting.¹⁸ Dental hygienists with PHS status, may provide preventive care to patients in public health clinics, provided there is a written supervision agreement from a dentist and approval for the planned treatment.¹⁸ A third provider, the expanded function dental assistant (EFDA) performs duties under the direct supervision of a dentist including taking impressions, cementing crowns, coronal polishing, fitting orthodontic brackets, and placing pit and fissure sealants.¹⁸ Although these providers are licensed to provide a range of services to patients in Maine, direct supervision by a dentist is required.¹⁸

Maine passed legislation (LD1230) DHT in 2014 establishing a midlevel oral health care provider, the Dental Hygiene Therapist (DHT).¹⁶ DHT must hold a bachelor's degree in dental hygiene and complete an additional 4 semesters of training from a Commission on Dental Accreditation (CODA) accredited dental therapy program.¹⁶ Unlike Minnesota's ADT, Maine's DHT must work under the direct supervision of a dentist and DHTs may not provide restorative care independently.¹⁶

Vermont passed legislation (S. 20) enabling dental therapists (DT) to practice in their state in 2016.¹⁷ The Vermont DT, after completing 1000 hours of patient care under direct supervision, would be able to deliver care independently, while under a collaborative agreement with a dentist.¹⁷ Vermont's DT is dental hygiene-based, DTs must hold a license to practice in the state and complete their DT training from a CODA accredited program.¹⁷

Legislation enabling dental health aide therapists (DHATs) to provide care to underserved residents and members of tribal lands and organization was passed by Washington state's House of Representatives and Senate in 2017.¹⁹ DHAT providers are required to complete a two-year training program, as well as a 400-hour preceptorship with a supervising dentist, prior to becoming licensed providers.²⁰

A number of states have legislation pending for midlevel dental providers including: Connecticut, Kansas, Massachusetts, Michigan, North Dakota, and Ohio.^21,22 In spite of the increasing number of states enacting legislation, little is known about the knowledge or interest of registered dental hygienists (RDHs) in enrolling in a dental therapy program, most specifically those licensed in the state of Maine. While legislators and oral health advocates were successful in creating the DHT license category, no academic programs for dental therapy exist in Maine or in New England. Maine state legislators and supporters of LD1230 requested assistance in producing evidence of RDHs interest to justify the launch of a dental therapy program in Maine, or regional program in New England. The purpose of this study was to assess the awareness of RDHs in the state of Maine, regarding the DHT provider model and to gather data regarding the degree of interest in enrolling in a DHT program.