INVESTIGATION OF CHARACTERIZATION AND COMPOSITION OF DENTAL WASTES IN SAMSUN CITY CENTER

As a result of daily activities, besides domestic wastes, many hazardous wastes also come out. These wastes constitute hazards in terms of environment and human health. Taking these potential hazards into account, waste must be disposed of in such a way as not to jeopardize the environment and human health. Looking at the overall hazardous wastes, it appears that dental wastes are a small fraction. Although it is thought to be a trivial part, it is in fact an important waste resource, with poor management, complicated infection risk and even heavy metal output from materials such as amalgam. Therefore waste characterization and composition should be determined to develop appropriate waste management systems. Just as dental residues are found in many countries, management of "medical waste control" is carried out by regulations in Turkey as well. In this study, it was aimed to determine the composition and characterization of dentistry wastes of Samsun city center. For this purpose, wastes of faculty of Dentistry, 2 dental clinics and 2 private dental examinations were taken and studied in two different days. In this study, wastes are classified by type, so that percentage distributions are calculated and quantities are examined.


INTRODUCTION
Medical wastes are not infectious danger in terms of public and environment when they are properly disposed. The important thing here is to know what the contaminants are and to distinguish them. This process is beneficial for protecting the people and society that collect the waste and it will significantly reduce the costs of disposal operations.
Medical wastes are considered under the title of hazardous waste in many literature. Health care waste are defined from WHO as discarded materials from health care activities that have the potential of transmitting infectious agents to humans [1]. According to this definition, medical wastes are dangerous for human and environmental health. For this reason, management and disposal must be done in certain rules. In most countries dental wastes are regulated under medical waste regulations [2]. Since 2005, medical wastes in Turkey have been collected, transported and disposed of under the control of medical waste regulation.
Dental wastes also form part of the medical waste. In many developing countries dental wastes are ignored because of the lack of quantity. In recent years, a significant increase has been observed in dental wastes. This is seen as an increase in the use of plastic barriers, gloves and mask. These materials are thought to constitute about 90% of the total weight of the waste [3].
Many sources categorize dentistry wastes into different subgroups. This classification is usually household-type wastes, infectious wastes, sharps, radioactive wastes, non-hazardous chemical wastes and hazardous chemical wastes. Even when looking at these subheadings, dental residues seem to have a risk of complicated infection due to the presence of infectious and hazardous wastes.
Protection from these risks is achieved through proper waste management. These wastes are not infectious danger in terms of public and environment when they are properly disposed. The important thing here is to know what the contaminants are and to distinguish them. This process is beneficial for protecting the people and society that collect the waste and it will significantly reduce the costs of disposal operations [4]. Waste management involves well separation, transportation and appropriate disposal method. According to Kızlary, 94.7% of these wastes and 71.15% according to Nabizadeh's work are non-infected wastes [5,6]. With separate collection and quantity tracking, infected waste can be minimized. In addition, the healthcare organizations are required to pay medical fees per kg of medical waste they produce, so characterization and quantification will be beneficial in terms of cost.

MATERIALS AND METHODS Description of Study Area
This study was conducted on the dental centers of Samsun city, located in the north of Turkey, in 2016. Samsun is the biggest city of the black sea and its population is 1,279,884 [7]. There are one School of Dentistry at Ondokuz Mayıs University, one state dental hospital, one oral dental health center, 2 private dental hospital, 2 dental clinics and 99 private dental office in Samsun city center [8]. A total of 384 dentists work in all these health institutions. In order to be generally descriptive, university hospital, 2 clinics and 2 private offices were selected for the study.

Data Collection
Each of the selected health institutions received samples for one day in April and May. The samples are just the wastes of that day. After 6 pm, the wastes collected from the health institutions were weighed within the same day. The wastes were first divided into classes and then each class was weighed separately. It was calculated that the total number of wastes divided into classes constituted the percentage of total waste. The number of patients from the day when the waste was taken from the health institutions was taken and the amount of waste per patient was calculated. Separation and weighing were carried out in a special solid waste laboratory with ventilation system. These operations were performed using dust and germicidal mask, cut and puncture resistant gloves, aprons and tongs.

RESULTS AND DISCUSSION Separation and Identification of Waste Components
All of the wastes were collected under 4 main headings first, infected, uninfected, sharps and hazardous. Then it is divided into 25 subclasses.

Private Dental Office Solid Waste
It is a health institution that a single physician works with an assistant. The number of patients per day varies between 4-7 people on average. There is no one trained in the separation of wastes. Separate collection of wastes is not carried out and all wastes are accumulated in the same waste bag. It is usually discarded after 1-2 weeks of waiting for the bags to fill. As shown in Table 1, the waste amounts of April and May are reported for the two offices.  As there is no separate collection, each class has waste. Table 2 shows the total amount of wastes and their distribution to classes. According to this, it can be said that the amount of waste per patient in a private dental office is 180 gr. In Figure 1, percentages of waste are given, with 66% of them forming infected wastes.

Dental Clinic Solid Waste
Dental clinic I is a clinic where 2 doctors, 2 nurses and 1 cleaning officer work. The average number of patients per month is 53 males, 47 females and 60 children. At the center there are all kinds of treatment for oral and dental health, in-patient and outpatient diagnosis and treatment, dental laboratory and research laboratories. There are no staff trained in medical waste collection and storage. The wastes are collected in medical waste bags, but there is no distinction between domestic, sharps and hazardous waste.
Dental clinic II is a clinic where 5 doctors, 4 nurses and 2 cleaning officer work. The average number of patients per month is 112 males, 86 females and 71 children. In the center there are 5 dental units, 1 general anesthesia and sedatable operative, dental laser devices, advanced technology periapical and panoramic devices. At the center there are 1 staff trained in medical waste collection and storage. The wastes are collected in autoclavable medical waste bags and the yellow plastic boxes specified for the sharps wastes are used. The clinic gives its medical wastes to medical waste collectors for a fee once a week. In Table 3, wastes belonging to both clinics are classified and waste quantities and patient numbers for that day are given. Table 4 and 5 give the total waste amounts and percentage distributions from clinics and Faculty of Dentistry respectively. From an average, it is about 1 kg of waste per day from a clinic. As shown in Figure 2, 69% of this waste forms infected wastes, on the other hand for faculty of Dentistry this rate is 73 % and this can be seen in figure 3. The amount of waste per patient for a clinic was calculated as 112.42 gr.

Faculty of Dentistry
Faculty of dentistry is used as a dental hospital. An average of 16,000 patients per month are treated at the hospital. There are 8 different departments in the hospital. These are pedodontics, periodontology, restorative, oral diagnosis, denture, endodontics, orthodontics and operating room. Due to the high health risk, operating room waste was not included in the weighing process. Pedodontia is a program aimed at relieving the problems of teeth and teeth caused by caries, trauma, hereditary and similar factors in the healthy protection of the dairy and permanent teeth of 0-13 year old children. Orthodontics is a science that investigates the anatomy physiology and histology of soft and hard tissues surrounding teeth and investigates diseases that occur in these tissues. Restorative is a specialist that deals with the treatment and follow-up of all discomforts related to tooth hard tissues, bacteria-originated or without bacteria. Oral diagnosis is the process of diagnosing the patient's xrays of the mouth region and performing a detailed intraoral examination. The prosthetic department is the unit that provides porcelain tooth, crown, bridge, nail tooth, implant tooth, denture, palate, hooked tooth. The endodontics department is the branch who deals with the problems that have advanced to the dental pulp and treats them. The department of orthodontics is a dentistry that focuses on the placement of the teeth on the jawbone aesthetically and in a taskable manner. As shown in Tables 6 and7, different waste sources are observed in the sections that have different operations.  Looking at all data and graphs, the amount of waste per patient was calculated as 180 gr in private dental office, 112.42 gr in dental clinics and 57.9 gr in faculty hospital. The difference in quantities may be due to differences in disposable materials and procedures. The reason for the low amount in the faculty hospital may be that the waste management is being done more regularly than the other health institutions. There is a serious problem in all organizations, especially if hazardous wastes are not collected separately. If only 5kg of hazardous waste per day is considered to be generated, this amount will be over 100kg per month. In this amount, proper disposal of a waste cannot be achieved. The amalgam in the faculty is an alloy containing heavy metals. In addition, healthcare organizations can reduce the amount of waste by collecting waste separately. Minimization of waste will be beneficial both in terms of health and cost.