Introduction
Plaque, stains and calculus accrue on dentures and oral mucosa of edentulous patients in a similar fashion as in mouths of dentulous patients. Dental plaque is an etiological factor in denture stomatitis, inflammatory hyperplasia, chronic candidiasis and offense odors and it must be removed.[1]
People remember less of what they hear than of what they see. So denture patients should be provided with printed information about new teeth, care and cleaning of teeth[1]. Many patients leave the dental office totally uninformed on how to properly care for their compete dentures. Dental profession should make specific recommendations on the proper and hygienic care of the oral prosthesis[2]. Regular and efficient hygiene procedures play a major role in the maintenance of oral health and are important for the long term success of removable prothodontic treatment. A variety of habits related to denture hygiene and duration of wearing of dentures has been reported in the literature. Patient’s oral and denture hygiene habits, frequency of use, method of choice for denture cleaning may vary in different societies as well as among individuals. The purpose of the present study was to evaluate denture hygiene habits and the relationship to oral tissue conditions in complete denture patients in the local population of Ludhiana.

Materials and methods : 242 complete denture patients of both genders attending OPD of department of prosthodontics were invited to participate in the study. Patients were informed about the research project and written consent was obtained. Ages of patients were between and years. Survey was performed by means of a questionnaire and clnical examination of their oral mucosa. Cleanliness of their dentures was assessed using dye disclosing method.

Questionnaire included following topics
1. Name, age, sex 2. Profession 3. Education 4. Duration of current denture 5. Method of cleaning denture 5.Overnight denture removal 6.Denture immersion technique 7.Instructions received from the dentist 8. Number of times denture is cleaned 9.Difficulty in denture cleaning 10.Tissue cleaning 11.Use of mouthwash 12.Examination of denture 13.Examination of tissues

Denture was removed , rinsed under tap water and then examined using dye disclosing method. Oral mucosa was also examined visually to assess the presence of denture stomatitis. In clinical examination denture hygiene levels were rated according to Budtz- Jorgensen’s Index(1970) as follows

Good :-none or only a few spots of plaque
Fair :- more extended plaque , less than half of the denture base covered by plaque
Poor:- more than half of the denture base covered by plaque
A chi square test was used to analyze the results and value of p<.05 were considered statistically significant and P<.001 as highly significant.

Results
242 patients consisting of males and females with the age range of to years participated in the study. Data referring to patient distribution according to age of current denture method of cleanind denture , overnight removal of denture, use of any mouth rinse, frequency of cleaning denture, difficulty faced in cleaning denture, instructions received from dentist, tissue cleaning, examination of denture for plaque are presented in the following table.

Table 1: Comparison Of Parameters Between The Groups At Baseline And 12 Weeks

All patients reported cleaning their denture daily with majority using toothbrush and paste. Most of the patients didn’t remove their dentures at night. Denture hygiene was rated as good for 146 patients, fair for 76 patients and poor for 20 patients. Most of the patients didn’t receive information regarding denture hygiene and care from their dentists. Statistically significant relation was found between denture hygiene and overnight removal, denture immersion, instructions given by the dentist, use of mouthwash. Statistically significant association was found between denture stomatitis and duration of wearing dentures, denture removal at night, immersion method, instructions given by the dentist, tissue cleaning.

Discussion
The study of oral hygiene in elderly denture wearers is becoming increasingy important because of the increasing numbers of the elderly people in the world. The survey revealed the denture wearing habits of a group of 242 patients.
95% of the patients were using toothbrush for cleaning dentures with majority using toothbrush with paste. Same results were found in a study conducted by Idil Dikbas and Takamiya [3],[4]. Only 5% partients reported using chemicals for denture cleaning. None of the patients knew about denture brushes or denture pastes. These observations could be because of improper instructions received by their dentist or lack of awareness among patients.
Dentures should not be worn at night to recover from the physical trauma of contact with appliances and to be relieved from contact with plaque and debris on the appliances.[5] 69.4% subjects didn’t remove their dentures at night . Barbosa[6] and Peracini[7] also observed similar results 64%and 58.49% respectively in their studies . In a study by Marchini[8], only 26.3% subjects removed their dentures. There is significant association found between denture hygiene, and overnight removal. Our study also showed statistically significant association between continuos use of denture and denture stomatitis. According to Zissis[9], patients who used to wear dentures day and night reported high prevalence of denture stomatitis.
Plaque adheres well to acrylic resin and requires thorough removal at least once a day, preferably following removal of the dentures prior to sleep.[5] All patients in the study cleaned their dentures on daily basis. These results agree with those of Patel et al.[10](100%), Peracini et al.[7](99.06%), Barbosa et al.[6](98%)Nevalainnen et al.[11](96%). Most of the patients were cleaning their denture once or twice daily whereas only 31.8% were cleaning dentures thrice or more. Dikbas et al.[3] reported 25% of the patients cleaning their dentures thrice daily. Frequency of cleaning didn’t correlate statistically with the condition of oral mucosa , also shown in study by Peltola et al.[12] In the present study 32% of the patients cleaned their dentures three or or more than three times daily. This frequency is close to that observed in study by Dikbas et al.[3] where 25% of the individuals reported cleaning their dentures three times daily.
Only 30% of the patients were using same denture for more than five years . This value is lower than observed in previous studies.[6],[7],[10]
64% of the patients immersed the denture in water and only 5% immersed in a chemical solution. This is in accordance with the study by Baran et al.[13] where 43% patients immersed their dentures in water and only 1.6% immersed in a chemical solution.
82% of the patients didn’t receive instructions from their dentists . similar results were reported in the previous studies.[3],[7],[14] 66% of the patients with good denture hygiene were previously instructed by the dentist. In the study conducted by Idil Dikbas et al.[3] same results were observed .Statitistically significant association was found between denture stomatitis and prior instructions. There is significant correlation between denture hygiene and instructions received from the dentist.
81.6% of the patients reported cleaning the soft tissues under the dentures everyday which is quite similar to value (86%)observed by Nevalainen in their study. Cleaning of the tissues showed significant negative relationship with denture stomatitis. Most of the patients were not using any mouthwash. Lack of awareness may be the reason behind this. Denture hygiene has significant association with use of mouthwash.
Significant correlation is there between poor denture hygiene and presence of stomatitis(p< .001). This is in accordance with study conducted by Ozkan et al.[15]
Denture hygiene was reported good in 60.3% of the patients in our study . This value is quite higher than reported by Dikbas et al.[3] and Saha et al.[16] Most of the dentures were in good condition followed by fair and poor condition. Almost similar results were reported by Ozkan et al.[15]

Conclusion
Degree of denture hygiene was found to be significantly associated with overnight removal, denture immersion, instructions given by the dentist, use of mouthwash and denture stomatitis. Most of the patients were not sufficiently informed about proper denture care. Within limitations of the study in can be concluded that complete denture wearers need improved education about regarding the same. It is the obligate of the dentist to educate the patient and responsibility of the patient to maintain denture hygiene.

References
1.    Bolender Z Prosthodontic treatment for edentulous patients 417
2.    Winkler S Essentials of Complete Denture Prosthodontics 335
3.    Investigation of the cleanliness of dentures in a university hospital. Dikbas I , Koksal T. International journal of Prosthodontics 2006;19:294-298
4.    Complete denture hygiene and nocturnal wearing habits among patients attending the Prosthodontic department in a dental university in Brazil. Takamiya A.S et al. Gerodontology 2011;28:91-96
5.    Grant A.A , Heath J.R, McCord J.F Complete Prosthodontics . Problems, Diagnosis and Management
6.    Edentulous patient’s knowledge of dental hygiene and care of prostheses. Barbosa L.C et al . Gerodontology 2008;25:99-106
7.    Behaviors and hygiene habits of complete denture wearers. PeraciniA et al. Braz dent journal 2010;21:3 247-252
8.    Self reported denture hygiene of a sample of edentulous attendees at auniversity dental clinic and the relationship to the condition of the oral tissues. Marchini L, et al. Gerodontology 2004;21:226-228
9.    Comparison of denture stomatitis prevalence in two population groups. Zissis et al. International journal of Prosthodontics 2006;19 621-625
10.    Behavours and hygiene habits of a sample population of complete denture wearers in Ahmedabad. Patel I.B et al. Braz Dental journal 2010 21;3:247-252
11.    Oral mucosal lesions and oral hygiene habits in the home- living eldery. Nevalainen M.J et al. Journal of Oral Rehabilitation 1997 24; 332- 337
12.    Effect of complete denture renewal on oral health- a survey of 42 patients. Peltola M.K et al. Journal of oral rehabilitation 1997 24; 419-425
13.    Self reported denture hygiene habits and oral tissue conditions of complete denture wearers. Baran I, Nalcaci R. Arch Gerontol Geriatr 2009;49:237-241
14.    Evaluation of denture hygiene among removable denture wearers referred to clinics of kerman , Iran Parizi M.T et al. Journal of oral health and oral epidemiology 2013;2:1 44-48
15.    Oral hygiene habits, denture cleanliness, presence of yeasts and stomatitis in elderly people. OzkanY.K et al. Journal of oral rehabilitation 2002 29; 300-304
16.    A survey assessing models of maintaining denture hygiene among elderly patients. Saha A et al. Journal of International Society of Preventive and Community Dentistry 2014;9:3 145-148