Management of dental waste in dental offices and clinics in Jeddah, Saudi Arabia

ABSTRACT

Management of dental wastes became a recent challenge facing health care practitioners and is one of the highly-sensitive environmental problems. The main purpose of this study was to assess oral health care provider’s knowledge and behavior about dental waste management and evaluate their behavior toward it. A cross-sectional descriptive study was conducted on 314 dental health care providers working in four dental colleges, and 20 private dental clinics in Jeddah, Saudi Arabia. A pretested questionnaire composed of close-ended questions was used. The mean age of the participants was 27 years. About 78% of the participants reported that they were working in the public sector. Only 33.4% of the study sample received professional training on waste management. The mean behavior and knowledge scores were 3.7 ± 1.3 (out of 6) and 1.4 ± 1.3 (out of 8), respectively. Statistically significant association was noted between gender and knowledge scores but not between gender and behavior scores. On the other hand, statistically significant associations were noted between both knowledge and behavior scores and rank of the participant, type of practice, and years of experience. Oral health care providers’ knowledge about the effective procedure that should be followed for segregating, collecting, transporting, and treating dental waste was weak and substandard. There is an urgent need to develop policies and regulations for dental waste management in Saudi Arabia.

Implications: This study shed light for the first time on the knowledge and behavior of dentists in Jeddah, Saudi Arabia in regard to the dental waste management. Participants knowledge and behavior in regard to dental waste segregation, collection, transportation, and treatment were determined to be week and substandard. Currently, different procedures related to dental waste management in health care facilities are not clearly described. The urgent need for the development of policies and regulations for the dental waste management is obvious. This study can be a starting point for future nation-wide surveys to assess knowledge, behavior and practices related to dental waste management among oral health care providers. In addition, more efforts should be directed to incorporate this subject into dental curriculum and continuous education courses.

Introduction

World Health Organization defines health care waste as “discarded (and untreated) materials from healthcare activities on humans or animals that have the potential of transmitting infectious agents to humans” (World Health Organization 2004). Dental health care service units generate variety of wastes that can be classified into hazardous, non-hazardous, biohazardous, pharmaceutical, and sharp wastes (Adil et al. 2014). These wastes may include blood socked dressing and bloody tissues, sharp objects, heavy metals, paper, cardboard, glass, gloves, needles, X-ray films, dental amalgam, infectious waste, materials, and instruments. Several studies assessed the amount of solid dental wastes produced per each patient or procedure daily. In Turkey, the solid dental wastes generated from eight different university specialty clinics were examined and the average produced wastes for two consecutive months were 398.3 and 194.7 g/procedure/day (Ozbek and Sanin 2004). In Greece, a study evaluated the amount of waste produced from 20 dental clinics and reported an overall unit production rate equals to 53.3 g/patient/day (Mandalidis et al. 2018). In Iran, the solid dental wastes generated from 159 dental centers in Sistan and Baluchestan Province was assessed, and the average amount of wastes produced was 193.5 g/patient/day (Bazrafshan et al. 2014).

Table 1. Demographic profile of the participating dentists.

		Total (N = 314)		Public (N = 244)		Private (N = 70)
		n	%	n	%	n	%
Gender	Male	104	33.1	72	29.5	32	45.7
	Female	210	66.9	172	70.5	38	54.3
Rank	Intern	182	58.0	12	62.3	30	42.9
	GD	64	20.4	45	18.4	19	27.1
	Specialist	38	12.1	27	11.1	11	15.7
	Consultant	30	9.6	20	8.2	10	14.3
Clinical experience (years)	≤ 5	246	78.3	197	80.7	49	70.0
	> 5 to ≤ 10	41	13.1	30	12.3	11	15.7
	> 10 to ≤ 15	12	3.8	6	2.5	6	8.6
	> 15	15	4.8	11	4.5	4	5.7

Table 2. Participants responses about the waste management protocol and policies in their practices.

Questions/Items		n	%
Waste collection, handling, and storage at the clinic is done by:	Dentist	75	24.0
	Dental assistant	100	32.0
	Cleaner or waste handler personnel	139	44.0
Did you receive any professional training on waste management?	Yes	105	33.4
	No	172	54.8
	I don’t know	37	11.8
Are you aware of any document outlining dental waste’s management policy?	Yes	176	56.1
	No	138	43.9
Are you aware of color-coding for different types of biomedical wastes?	Yes	212	67.5
	No	102	32.5

Table 3. Responses to different knowledge questions.

Question	Possible Answers	n	%
Q1 K: Where is silver amalgam excess stored?	Disposed of into common bin	25	8.0
	Stored in an air-tight container	42	13.4
	Stored in an air-tight container with water	97	30.9
	Stored in fixer solution	24	7.6
	I don’t know	126	40.1
Q2 K: Where are lead foils disposed of?	Common bin	38	12.1
	Stored and disposed of in separate container	45	14.3
	Sold to certified buyers	16	5.1
	Others (RVG/no unit)	27	8.6
	I don’t know	188	59.9
Q3 K: Where are exposed X-ray films disposed of?	Stored separately and disposed of in common bin	47	15.0
	Buried in soil	10	3.2
	Disposed of in secured landfill	31	9.9
	I don’t know	226	72.0
Q4 K: Where areorthodontic wires and brackets disposed of?	Deformed and disposed of in common bin	40	12.7
	Sold to certified buyers	21	6.7
	Other “Sharps Container containing 1% Sodium hypochlorite”	63	20.1
	I don’t know	190	60.5
Q5 K: Where are developer and fixer solutions disposed of?	disposed into sewer	20	6.4
	Diluted and led into sewer	36	11.5
	Returned to the supplier	14	4.5
	Others (RVG/no unit)	15	4.8
	I don’t know	229	72.9
Q6 K: Where are outdated and contaminated medicines disposed of?	Common bin	32	10.2
	Deformed and disposed of in common bin	20	6.4
	Buried in soil	8	2.5
	Disposed of in secured landfill	42	13.4
	I don’t know	212	67.5
Q7 K: Where does final dental care waste get disposed of?	Corporation bin	39	12.4
	Certified collectors	108	34.4
	I don’t know	167	53.2
Q8 K: How long is dental waste kept before being removed from the clinic\storage area?	5 days or less	191	60.8
	More than 5 days	12	3.8
	I don’t know	111	35.4
Correct responses are highlighted.

Table 4. Responses to different behavioral questions.

Question	Possible Answers	n	%
Q1B: Do you segregate different types of wastes in your clinic?	Yes	230	73.2
	No	33	10.5
	I don’t know	51	16.2
Q2B: Do you use color-coded bags for waste disposal in your clinic?	Yes	209	66.6
	No	75	23.9
	I don’t know	30	9.6
Q3B: How do you dispose of infected needles?	Dispose of in common bin	63	20.1
	Break the needle and dispose in common bin	19	6.1
	Destroy the needle in needle burner	56	17.8
	Dispose of in puncture proof bags (or containers)	176	56.1
Q4B: Do you wear a facemask during patient treatment?	Never	5	1.6
	Sometimes	63	20.1
	Always	246	78.3
Q5B: Do you wear eye protection glasses during patient treatment?	Never	29	9.2
	Sometimes	164	52.2
	Always	121	38.5
Q6B: What type of sterilization for headpieces do you use?	Dry heat	14	4.5
	Autoclave	189	60.2
	Both	45	14.3
	I don’t know	66	21.0
Correct responses are highlighted.

Table 5. Descriptive statistics for knowledge and behavior scores.

		Knowledge		Behavior
Median		1.0		4.0
Mean		1.4		3.7
Standard Deviation		1.3		1.3
Total No. of Questions		8		6
Maximum		6		6
Minimum		0		0
No. of Correct Answers		n	%	n	%
	0	87	27.7	2	0.6
	1	100	31.8	15	4.8
	2	72	22.9	42	13.4
	3	32	10.2	63	20.1
	4	18	5.7	98	31.2
	5	4	1.3	73	23.2
	6	1	0.3	21	6.7
	7	0	0	-	-
	8	0	0	-	-
	Total	314	100	314	100

Table 6. Bivariate statistics for association between knowledge and behavior scores and different independent variables using the Mann--Whitney test.

Independent Variables		Knowledge Score					Behavior Score
		Mean	Median	Standard Deviation	P-value	Mean		Median	Standard Deviation	P-value
Gender	Male	1.8	2.0	1.3	< 0.001	3.9		4.0	1.3	0.135
	Female	1.2	1.0	1.2		3.7		4.0	1.3
Rank	Interns or GDs	1.3	1.0	1.2	0.006	3.6		4.0	1.3	0.013
	Specialists or Consultants	1.8	2.0	1.4		4.1		4.0	1.4
Type of practice	Public	1.3	1.0	1.2	0.001	3.6		4.0	1.3	0.008
	Private	1.8	2.0	1.3		4.1		4.0	1.2
Clinical experience (years)	≤ 10	1.3	1.0	1.2	0.001	3.6		4.0	1.3	< 0.001
	> 10	2.1	2.0	1.3		4.7		5.0	1.3

Dealing with these variety of wastes is a challenge that face health care providers as they may contain pathogenic and toxic factors that cannot be disposed of directly to the environment. In addition, collection, recycling, and disposal of dental wastes depend on their components. As radioactive waste must be separated from other wastes, so infectious and sharp wastes must be collected separately in a puncture resistant container (Darwish and Al-Khatib 2006). It is important for any dental organization to segregate and dispose of their wastes correctly (Bazrafshan and Mostafapoor 2010). Any deviation could mean a danger to the dentist, the public, and the environment through the production of toxins and infectious agents that might be generated from the disposal process (Adedigba et al., 2010). If those wastes are manipulated without precaution, they could end up in municipal waste. This might cause transmission of dangerous infectious diseases such as HIV and hepatitis. They can also have negative environmental impacts that might be caused by heavy metals and radioactive components.

The management of dental waste is relatively new environmental issue that has received a significant focus in recent years and has been the main subject for several studies in different countries (Danaei et al. 2014). Previous studies indicated that there is a problem with the knowledge, attitude, and behavior of dental practitioners in regard to the management of dental waste. In New Zealand, qualitative interviews with practitioners indicated a lack of concern about disposal of contaminated waste into the general waste with the existence of legislation governing waste disposal not being sufficient to motivate many practitioners to comply with guidelines (Treasure 1997). In Palestine, a cross-sectional study, which was conducted over a period of five months in 2007, reported that most dental waste was tossed in the standard junk. This study reported that oral health care providers were not mindful of biomedical waste management protocol to be practiced (Al-Khatib et al. 2010). A study in Brazil (Vieira and de Carvalho 2011) evaluated the microbial content of dental solid waste and its antibiotic susceptibility produced by three dental health services and revealed misclassification of most biomedical waste. A cross-sectional study that included 595 private and public dental offices and clinics in Shiraz University, Iran revealed about 90% of dental workplaces and facilities that arranged their contagious waste with interior waste and only 60% of centers utilized a standard system for sharps transfer (Danaei et al. 2014). Another study in Lebanon clearly expressed that only 28% practitioners segregated sharp waste in an appropriate container; only 70% of dentists reported treating their infectious waste before disposal; about two thirds of the surveyed dental practitioners do not follow the local guidelines; and half of them do not provide the proper precautionary measures while managing the dental wastes. Furthermore, the majority of participants (90%) in this study acknowledged a lack of written procedures for waste management (Daou et al. 2015). Similarly, results from a study conducted in Bangkok indicated that only a few dentists complied with all the recommendations for the disposal of wastes, with high percentage of waste being disposed of into domestic rubbish stream, which indicated a need to recommend an alteration in the behavior of the practitioners (Aghalari, Amouei, and Jafarian 2020; Agrawal et al. 2015). This significant mismanagement of dental waste reported in different countries indicates the need for training programs for all levels of dentistry unit staff from dentists and dental assistants down to waste handlers and maintenance and incinerator operation staff (Adedigba et al. 2010; Bazrafshan and Mostafapoor 2010).

Although there are several studies conducted all over the world to assess knowledge and behavior of dental staff toward dental wastes, none of these studies were conducted in Saudi Arabia. This lack of data when combined with the absence of clear regulations and policies for the dental waste management is alarming. Assessing oral health care providers’ knowledge level and practices in relation to dental waste management are required to evaluate the situation. Hence, the main objective of this study was to assess oral health care provider’s knowledge level about dental waste management and evaluate their behavior toward it.

Materials and methods

Ethical approval

Research ethical approval of the study was obtained from the Research Ethic board/committee at KAUFD. Participants were asked to participate in the study voluntarily after the explanation of the purpose of the study.

Study design

A cross-sectional descriptive study was conducted to assess the knowledge and behavior of oral health care providers toward the management of dental waste in dental offices and clinics in Jeddah, Saudi Arabia.

Study Site: This study was conducted in four governmental and private dental colleges (The Faculty of Dentistry at King Abdulaziz University “KAUFD,” Ibn-Sina National College for Medical Studies “ISC,” Batterjee Medical College “BMC,” and Al-Farabi Private College) and 20 other private dental clinics.

Sample size calculation

The sample was estimated to be 306 based on the formula presented in the article by Taherdoost based on the following parameters: population size = 1,500; variability level = 50%; confidence level = 95%; and margin of error = 5% (Taherdoost 2017).

Survey tool

Data were obtained using a structured, self-administered, close-ended online questionnaire. The questionnaire was divided into three parts. The first part included questions about demographic data such as gender, age, qualification, and practicing dentistry status.

The second part of the questionnaire was aimed to assess the level participants’ awareness and knowledge regarding dental waste management. In this section, participants were asked if they received any professional training on waste management and if they are performing proper personal protection protocols using Personal Protective Equipment (PPE). Also, they were asked about their awareness of different color-coding for different types of biomedical waste produced, how it is managed, who the staff personnel responsible for its disposal is. Questions about Infected needles, excess silver amalgam, orthodontic wires, outdated medicine, X-ray films, and solution disposal were addressed. The questionnaire needed about 10–15 minutes to be answered.

The third part was directed to assess the participants’ behavior in regard to dental waste management in their work places.

All knowledge and behavior questions were scored with one (1) if answered correctly, or zero (0) if not (unanswered items were also scored zero). The knowledge and behavior scores were calculated by summing the correct responses for the knowledge and behavior questions, respectively.

Data management

Data obtained were entered and analyzed using the SPSS software for Windows (Version 22, SPSS Inc., IBM, Somers, New York, USA). Descriptive statistics were used to summarize the recorded variables. Spearman’s correlation was used to assess the correlation between knowledge and behavior scores. Comparisons of knowledge and behavior scores among different demographic variables were assessed using the Mann--Whitney test. All statistical tests were two-tailed and conducted at significant level of 0.05.

Results

About 410 potential candidates were approached to participate in the study. A total of 314 participants agreed to participate and filled the questionnaire giving a response rate of 76.5%. The age of the participants ranged from 25 to 66 years with the mean age of 27 ± 6, and about 67% of them were females. The majority of the sample (about 78%) were interns or general dentists (GD), while the remaining 22% were consultants or specialists. Among the respondents, majority of the participants were from the public sector (77.7%) and about 78.3% had a clinical experience of five years or less. The demographic profile of the participants is presented in Table 1.

More, the half of the sample (About 56%) reported that dentists or dental assistants are responsible for handling and storing waste in their clinics, and the rest of the participants (about 44%) reported that waste handling and storage is the responsibility of the cleaners or waste handling personnel. About 55% of the participants did not have any professional training in waste management and about 44% were not aware of any document outlining the waste handling protocol in their clinics. About two-thirds of the sample were not aware of the color-coding for different biomedical wastes. Participants’ responses to questions about waste management protocol and policies in their practices are shown in Table 2.

Concerning the eight knowledge questions that were asked about dental waste management and handling, percentages of the correct answers did not exceed 20% for most of the questions except one of the questions about the length of time that dental wastes can be kept before removing it out of the clinic/store area. Responses to different knowledge questions can be seen in Table 3.

Regarding the six behavior questions that were asked about dental waste management and handling, percentages of the correct answers exceeded 60% for four of the questions. Lowest percentages of the correct answers were observed for the questions about disposal of the used needles and usage of protective eyeglasses, 56.1% and 38.5%, respectively. Responses to different behavior questions can be seen in Table 4.

Although the number of behavior questions was lower than the number of the knowledge questions, results revealed higher behavior score in comparison to the knowledge score with a mean of 3.7 ± 1.3 and 1.4 ± 1.3, respectively. About 61% of the participants had correct answers for more than half of the behavior questions with the highest score being six out of eight, while only 2% of the participants had correct answers for more than half of the knowledge questions with the highest score being six out of eight. Spearman’s correlation revealed a statistically significant positive correlation between both knowledge and behavior scores (r_s = 0.379, p < .001). Descriptive statistics for the knowledge and behavior scores were summarized and reported in Table 5.

Statistically significant association was noted between gender and knowledge scores but not between gender and behavior scores, with higher mean knowledge score for the male participants in comparison to the female participants. On the other hand, statistically significant associations were noted between both knowledge and behavior scores and rank of the participant, type of practice, and years of experience. Specialist or consultants scored higher than interns and GPs in both knowledge and behavior questions. In addition, those who practice in the private sectors scored higher than those who practice in the public sector in both knowledge and behavior questions. Finally, participants with more than ten years of clinical experience showed a higher mean knowledge and behavior scores in comparison to participants with less than ten years of clinical experience. The association between selected independent variables and knowledge and behavior scores are reported in Table 6.

Discussion

This study was an effort to investigate the dental health care waste management procedures in Jeddah, Saudi Arabia with the results revealing a low and substandard knowledge level. The hazards of waste disposal from dental practices can be divided into two main areas. First, there is a wider environmental burden of a variety of hazardous products that are used in dentistry, and second, the more immediate risks of potentially infectious materials among dental waste. Improper handling of dental waste can cause harm to dental personnel, cleaners, human beings and the environment in general.

The present study can be considered as a starting point as it focused on students and staff in academic institutes. Future projects should be directed to public governmental and private dental facilities in the city of Jeddah and nation-wide.

In the present study, 56.1% of the dentists were aware of document outlining dental waste’s management policy in their facility, which is similar to a study conducted by Janakiram and Vidyapeetham (2008) in Bangalore in which 57.6% were aware, while other studies conducted by An (2011) in Chennai City and Kishore et al. (1999) in New Delhi, reported awareness of 72% and 36%, respectively. This shows that awareness of waste management policy varies between cities.

About 33% of the dentists said that they received a professional training on waste management, which is similar to a study conducted by Daou et al. (2015) in Lebanon, in which 41% of the involved participants received training programs on health care waste management.

When asked about the color coding for different categories of biomedical waste, 73.2% said that they are aware, which is similar to the studies conducted in Davangere and Chennai Cities in India by Sudhir (2006) and An (2011), respectively.

About 8% of the dentists get rid of the excess silver amalgam into a common bin, which is similar to the study conducted by Sudhir (2006), in which 11.3% of the participants reported disposal of silver amalgam into the common bin, and in contrast to the studies conducted by Janakiram and Vidyapeetham (2008) and Al-Khatib et al. (2010). Surprisingly, only 7.6% of the participants in the present study reported that they are storing amalgam waste in a fixer solution, which is the recommended method by the American Dental Association (ADA) (American Dental Association, 2007).

About 12% and 15% dispose of the X-ray film lead foils and X-ray film into the common bin, respectively, which is not permitted because lead is a heavy metal that affects neurological development and functions. It should not be incinerated nor treated as general waste but disposed of in secured landfill. Some of the factories may use lead as a raw material for the manufacture of batteries, but the quantity required is high (Hegde, Kulkarni, and Ajantha 2007).

It was noted that 12.7% dispose of orthodontic wires and brackets into the common bin. According to OSHA (Occupational Safety and Health Administration; Dentistry OSHA Standards) regulations, orthodontic wires are considered as sharp wastes because the ends of orthodontic wires can penetrate the skin and their contamination with blood can reasonably be anticipated. Thus, they should be disposed of as sharp waste, while orthodontic brackets should be disposed of as recyclable wastes.

About 18% of the participants disposed of the developer and fixer solutions into the sewer, which is in contrast to the study conducted by Al-Khatib and Darwish (2004) in Palestine. Developer and fixer solutions contain silver, and if disposed of into the sewer, they will increase the metal load in the sewer, which is not allowed per environmental protection rules (used fixer solution contains approximately 4,000 mg of silver per liter). Silver in these solutions can be recovered using a special recovery unit. Alternatively, these solutions have to be stored separately and should be handed over to certified buyers who will extract silver from them (Muhamedagic et al., 2009).

In the present study, about 10% of the participants dispose of outdated and contaminated medicines into the common bin. This is not in agreement with the fact that these medicines are considered as cytotoxic waste and should be disposed of in a secured landfill (Bindra et al. 2015).

In this study, about 73.2% of the dentists segregate the wastes generated in their clinic, which is similar to the result of the study conducted by Janakiram and Vidyapeetham (2008) in which 64.3% practiced segregation, in contrast to the study conducted by Sudhir (2006) and Al-Khatib and Darwish (2004).

About 20% of the dentists disposed of the infected needles into the common bin, which is similar to the study conducted by (Treasure and Treasure 1997) in New Zealand, in which 24.4% of participants disposed of them into the common bin. In present study, more than half of the sample (56.1%) of the dentists reported that they are using puncture proof bags to dispose of needles, which is the ideal method. This is in agreement with the studies conducted in Kenya (La et al. 2005) and Ajman, United Arab Emirates (Hashim, Mahrouq, and Hadi 2011), in which 61% and 56% of respondents applied the recommended manner for sharps/needles, respectively.

When asked about infection control practices, only 78% of the participants stated that they always use facemasks during treatment and only 38.5% of them reported that they always use protective eyeglasses. These percentages are considered low when it comes to dentistry due to common risk of splashing or spattering of blood or other body fluids.

The average knowledge score for the participants in this study was 1.4 ± 1.3, which indicates that the participants’ knowledge of how to deal with dental waste properly is low and not satisfactory. This emphasizes the need for incorporating this subject into the dental curriculum and the continuous education courses in order to fill the knowledge gap.

In fact, there are no specific policies and regulations in Saudi Arabia to deal with the dental clinics waste. Different procedures for segregating, collecting, transporting, and destroying waste from dental clinics are not clearly described. The urgent need for the formulation of these policies and regulations is obvious. This is no longer acceptable in the practice of modern dentistry, and concerned bodies should take the necessary measures to resolve this issue.

This study shed light for the first time on the knowledge and behavior of dentists in Saudi Arabia in regard to the dental waste management, in the hope that this information will stimulate those interested to develop policies and procedures for the dental waste management.

Conclusion

The oral health care providers’ knowledge level about the effective procedure that should be followed for segregating, collecting, transporting, and treating dental waste was weak and substandard. There is a need to develop policies and regulations for dental waste management in Saudi Arabia, and more efforts should be directed to incorporate this subject into dental curriculum and continuous education courses.

Acknowledgment

The authors acknowledge the DSR technical and financial support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the The Deanship of Scientific Research (DSR), King Abdulaziz University, Jeddah, Saudi Arabia [grant No. (G-348-165-1439)].

Notes on contributors

Dania A. Sabbahi

Dania A. Sabbahi, BDS, M.Sc., Ph.D. (Dental Public Health), is an assistant professor in the Dental Public Health Department at Faculty of Dentistry, King Abdulaziz University. She received her BDS degree from Faculty of Dentistry, King Abdulaziz University. She graduated from University of Toronto, Canada with a Master’s degree in Science in 2008. In 2013, she obtained her PhD degree in Dental Public Health from the same university. She has published in peer-reviewed international journals and has presented in several international dental conferences.

Hesham M. El-Naggar

Hesham M. El Naggar is an associate professor of dental public health (King Abdulaziz University) in Jeddah, Saudi Arabia. Hesham is teaches undergraduate Public Health courses. And also, he is an associate professor of environmental health (High Institute in Public Health) in Alexandria, Egypt. His main specialty is environmental health and he teaches various graduate Public Health courses and the main coordinator for the field trips in the Institute of Public Health for more than 6 years. His first priority is the community service and he participated in more than 50 community services in Egypt and Jeddah.

Mohammed H. Zahran

Mohammed H. Zahran, BDS, M.Sc., Ph.D., FRCD(C) (Prosthodontics), is an assistant professor in the Oral and Maxillofacial Prosthodontics Department at Faculty of Dentistry, King Abdulaziz University. He received his BDS degree from Faculty of Dentistry, King Abdulaziz University. He graduated from University of Toronto, Canada with a Master’s degree in Science in 2006. In 2013, he obtained his Ph.D. and specialty training in Prosthodontics from the same university. He is a fellow of the Royal Collage of Dental Surgeon of Canada. He has published several articles in peer-reviewed international journals and has presented in several international dental conferences.