Knowledge, Attitude and Practice on Dental Amalgam Restoration among Dental Students

Amalgam has been used in Dentistry for about 150 to 200 years and is still under use due to its low cost, ease of application, strength and durability. It is an alloy of mercury, is an excellent and versatile restorative material. The development of various tooth coloured cements and resins serves as an alternative and have reduced the use of amalgam. Yet, amalgam stands as one of the excellent restorative materials. The aim of the study was to assess the knowledge, awareness and practice of dental amalgam among dental students in a private dental school. Study was conducted as a cross sectional questionnaire based study among the dental students. The study was conducted as an online survey as it is timesaving and a majority of the population can be covered. There were one hundred participants involved in this online survey from second year, third years, final years and internship. The questionnaire consisting of ten questions were posted for an online survey using google forms. The validity of the questionnaire was cross verified by experts. The data were extracted and tabulated in MS Excel sheets with respect to each question and their response. Original Research Article Natarajan and Ranjan; JPRI, 32(19): 39-48, 2020; Article no.JPRI.59813 40 The data obtained were subjected to statistical analysis using SPSS software v20. Chi square test was done to assess the association between the variables. The descriptive data obtained were plotted in bar graphs. It was evident that interns had adequate knowledge about amalgam restorations than other participants.


INTRODUCTION
Amalgam has been used in Dentistry for about 150 to 200 years and is still under use due to its low cost, ease of application, strength and durability [1]. It is an alloy of mercury. Amalgam consists of an alloy of silver, copper, tin and zinc combined with mercury. Modern amalgams are available in capsule form that consist of 45% of mercury. There are several advantages of pre capsulated amalgams that include convenience in use, reduction or sometimes there is no evidence of amalgam spill during mixing [2].
Research done on the durability of amalgam has shown that the restorations last longer than expected. Older generation amalgam (low copper amalgams) had a comparatively shorter lifespan due to the presence of gamma 2 phase that caused weakening of the restoration by corrosion. Studies have proved that the high copper amalgams have a satisfactory performance. Also, high copper amalgam does not necessarily require polishing after placement whereas it is important in low copper amalgam to increase its longevity. Copper when combined with zinc provides resistance to the restoration from corrosion [3]. However, other factors that cause damage to the restorations like marginal fracture, bulk fracture, tooth fracture are still reported [4].
To overcome the microleakage of amalgam, a coating of resin was used over amalgam restoration. This was not as effective as expected because the resin would wear away after some time however it delayed the microleakage [5]. Fluoridated amalgam was introduced to produce a cariostatic effect and to reduce recurrence of caries around the amalgam restoration studies have confirmed that fluoride containing amalgam released fluoride for several weeks thus acting as a slow release device [6]. Bonded amalgam was introduced to avoid mechanical retention of the restorations. A mechanical retention requires proper cavity design and loss of more tooth structure whereas bonded restorations allows more sound tooth structure to be preserved [7].
In the year 1843, American Society of Dental Surgeons declared the use of dental amalgam to be malpractice due to the fear of mercury poisoning both in patients and dentists. Studies were done to assess the mercury level in urine of patients and dentists. This led to the emergence of amalgam war. Three amalgam wars have been reported in the years 1845, 1926 and 1980s respectively. Few patients have reported allergic reactions due to amalgam restorations [8].
The development of various tooth coloured cements and resins serves as an alternative and have reduced the use of amalgam. Glass ionomer cements preferably in children is used for biocompatibility, fluoride releasing property and ease of manipulation. Composites have made a complete change in the trend from extension for prevention to prevention of extension. Particularly flowable composites have become a versatile material in the restorative field [9]. They are highly preferred by both patients and dentists for the aesthetics and conservative cavity preparation. Among all these developments in restorative materials, amalgam still stands as one of the excellent restorative materials, some studies continue to support the position that dental amalgam is a safe restorative material [1]. Dental amalgam can be a good choice wherever caries extends towards root since composite restorations in those cases fails due to poor bonding to the dentin or cementum. In certain cases, secondary caries leads to involvement of pulp which ultimately goes for root canal treatment. We have numerous highly cited publications on well designed clinical trials and lab studies related with different aspects of management of deep caries and root canal treatment procedures [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Amalgam restorations are indicated wherever resistance against occlusal forces, microleakage and bonding failures are primarily affecting the lifespan of the restoration. This particular aspect of amalgam restorations has initiated a right platform for us to pursue the current study. Our aim is to perform a cross sectional survey among undergraduate students of a private dental school to assess knowledge, awareness and practices about dental amalgam among dental students.

Study Setting
Study was conducted as a cross sectional questionnaire based study among the dental students to find out the trend regarding dental amalgam. The study was conducted as an online survey as it is time saving.

Survey
Hundred participants of the same institution were involved in this online survey. The questionnaire were prepared after searching various aspects of dental amalgam which consist of ten questions and it was posted for an online survey using google forms. The validity of the questionnaire was cross verified by experts i.e guide, reviewer and researcher.

Data Collection and Tabulation
The data were extracted and tabulated in MS Excel sheets with respect to each question and their response.

Statistical Analysis
The data obtained were subjected to statistical analysis using SPSS software v20. Chi square test was done to assess the association between the variables. The statistical significance was set at 5%. The descriptive data obtained were plotted in bar graphs.

RESULTS
This study was a questionnaire based survey. An online survey link was shared and after few days the responses were collected. There were a total of 100 undergraduate participants who participated in the study.

DISCUSSION
There were a total of 100 participants (55% females, 45% males). The association between gender and year of study revealed 13%, 17% 12%, 13% of second years, third years, final years and interns were females, 12%, 8%, 13%, 12% of second years, third years, final years and interns were males. The association between source of knowledge and the year of study was statistically not significant (p value = 0.497). The association between source of knowledge and year of study revealed that 5%, 10%, 8%, 6% of second years, third years, final years and interns respectively responded books, 10%, 10%, 5%, 6% of second years, third years, final years and interns respectively responded internet, 5%, 3%, 2%, 7% of second years, third years, final years and interns respectively responded conference, 9% and 6% of final years and interns responded through patient inquiries, 5%, 2%, 1% of second years, third year and final year responded colleagues (Graph 1). The association between source of knowledge and the year of study was statistically significant (p value = 0.002). The association between opinion on amalgam use and year of study revealed that 8%, 13%, 7%, 9% of second years, third years, final years and interns respectively responded safe, 11%, 8%, 8%, 11% of second years, third years, final years and interns respectively responded unsafe, 6%, 4%, 10%, 5% of second years, third years, final years and interns respectively responded uncertain (Graph 2). The association between opinion on amalgam and the year of study was statistically not significant (p value = 0.368). The association between the criteria to choose amalgam as a restorative material and year of study revealed 7%, 9%, 4%, 1% of second years, third years, final years and interns respectively responded older age, 2%, 3%, 10%, 11% of second years, third years, final years and interns respectively responded extend of caries, 7%,10%, 6%,11% of second years, third years, final years and interns respectively responded affordability, 9%, 3%, 5%, 2% of second years, third years, final years and interns respectively responded patients acceptance (Graph 3). The association between the criteria to choose amalgam and the year of study was statistically significant (p value association between educating the amalgam and its adverse effects study revealed that 16%, 13%, second years, third years, final years respectively responded yes, 9%, of second years, third years, and interns respectively (Graph 4). The association between the patient about amalgam and effects and the year of study not significant (p value = association between why amalgam frequently and year of study revealed 4%, 1% of second years, third years, and interns respectively responded 9%, 7%, 8%, 11% of second years, final years and interns respectively aesthetic concern, 2%, 7%, 13%, years, third years, final years respectively responded alternate material (Graph 5). The association amalgam is not used frequently study was statistically significant 0.001).
The association between preferred restorative material and year of represents the year of study revealed 12%, 15% of second years, third    The awareness about amalgam, and its adverse effects among are adequate. There were equal students from each year, however distribution showed that most of were females. The source of knowledg amalgam varied among students, them acquired through the internet Most of the interns felt the use unsafe, while a ratio of people This variation may be due to the study population or lack of awareness Interns were aware that the choice material was based on the extension and patients affordability, while responded it was based on age.
Most of the interns responded educate their patients about amalgam, years and final years responded patients prefer replacement restoration with tooth coloured dentists must educate the patient make them participate in an informed process before the placement well as during removal of the old Interns were aware of the alternate materials used instead of amalgam association between the year of study and number on amalgam disposal. X axis represents the year interns), Y axis represents the number of respondents. = 0.001 (< 0.05) -statistically significant. From were aware of the amalgam disposal protocols years were not aware of the disposal protocols amalgam, its properties the respondents equal ratios of however gender the respondents knowledge about students, but most of internet and books. of amalgam was were uncertain. the disparity in the awareness [25]. choice of restorative extension of caries while second years that they would amalgam, while third responded no. since a lot of amalgam restoration [26], patient and should informed consent of amalgam as old amalgam [25]. alternate restorative amalgam and most of them preferred the use of composite of the preferred glass ionomer preferred GIC for its fluoride and ease of manipulation and enhancement in aesthetics mechanical bonding [27,28 composites are aesthetically for the clinician. For instance technique used in composite the restoration easy and aesthetically [29].
However, the respondents longevity and durability provided irreplaceable [30]. On discussing amalgam, second years were amalgam about it, while interns knowledge. It is important to disposal kit in every clinic [31  can conclude that the knowledge about amalgam as experience compared to had poor knowledge are still undergoing Most of them felt the use of amalgam is unsafe, yet it remains controversial. However it is clear from above results that better clinical as well theoretical training is required to have a better understanding of uses of amalgam and its disposal at undergraduate level itself.

CONSENT AND ETHICAL APPROVAL
As per university standard guideline, participant consent and ethical approval have been collected and preserved by the authors.