Clinical Profile and Therapeutic Implications on Patients Restored by Removable Prosthesis : A Survey Study in the Department of Odontology of Dakar

This cross-sectional and descriptive study aimed to describe the clinical profile of patients treated by removable prosthesis in the clinic of the Department of Odontology. The survey carried out using anamnesis and clinical examination of patients. The variables were about general and local nature. The statistical analysis was made by SPSS Version 16.0 with a risk error of 5%. The sample consisted of 51 patients including 80.4% of men. Their average age was 60.1 years. They were generally in good health (56.9%), with a sound supporting soft tissue (80.4%) and had bone resorption at the stage 3 of Atwood scale (74.5%). Full removable prosthesis was worn by 62.75% of the sample. The majority (54.9%) of the patients wore full removable prosthesis on the antagonist arch and 5.9% had a complete dental arch. The posterior edentulism accounted for 33.3%. Lesions of supporting soft and hard tissues observed are likely to promote prosthetic failure. In order to support the adaptation of their prosthesis, the execution of an adequate organization of rehabilitated patients recall procedures could constitute an appreciable alternative.


Introduction
The number of edentulous people requiring prosthetic rehabilitation increases gradually with the lengthening of life expectancy [1].The prevalence of removable prosthesis wearing differs depending on the country's level of development, due to a complex interplay between economic and socio-cultural factors influencing access to oral health care.In the United States, 56 million uni or bi-maxillary prostheses were distributed in 2000 [2].The trends are weaker in the developing countries where studies reveal that 81.8% of people attending the dental clinics had diagnosed need for prostheses [3,4].
Various advancements have improved the quality of a removable prosthesis, subsequently improving edentulous patients' quality of life by re-establishing their oral health [5][6][7][8].Wearing prosthesis implies the participation of the oral cavity supporting soft and hard tissues.The prosthetic integration is an involved process influenced by general factors, local constraints and the degradation of prosthetic materials [9,10].
This study aimed to describe the clinical profile of patients treated by removable partial or full prosthesis in order to evaluate the therapeutic implications.

Materials and Methods
This was a descriptive, cross-sectional, retrospective study carried out in 2012, in the clinic of prosthodontics of the Department of Odontology.The survey lasted one month.The data-gathering was exhaustive after a recruitment carried out starting from the files of patients rehabilitated by removable prosthesis.The survey included voluntary patients of both sexes, wearing a full or partial, transitional or permanent removable prosthesis realized between 2008 and 2011 and having positively answered the telephone convocation.The patients using prosthetic adhesive, those having benefited from a re-intervention on their prostheses and those unable to answer our questions or to communicate clearly did not take part in the investigation.The data collected were treated in the confidentiality and by preserving the subjects' anonymity.
The variables observed were general factors (age, sex, state of health) and local factors (prosthesis location, antagonist arch characteristics, edentulism situation, mucosa condition and bone resorption).The investigation was carried out by one operator using a questionnaire and doing the anamnesis of all patients.The clinical examination was made at chair side with standard conditions.The statistical analysis was performed using SPSS version 16.0 software.The risk of error was fixed at 5%.

Results
On the 115 folders of rehabilitated patients initially indexed, 51 were retained for the investigation that means a rate of recall of 44.3%.Among the not-surveyed patients, two did not use their prostheses, three had lost them, and the others could not be joined by phone or did not agree to take part of the investigation.The sample consisted of 51 patients including 41 men (80.4%) and 10 women (19.6%).The sex-ratio was 4.1.The average age was 60.1 years with a standard deviation of 10.06.
More than half of the sample (56.9%) was in good health.Among the unhealthy patients, 23.5% were diabetic and 9.8% had a cardiovascular pathology (Table 1 and the partial removable prostheses by 37.25%.The permanent prostheses accounted for 82.3%.For all the prostheses, denture teeth set up was made selecting resin acrylic teeth and 51% of them were located at the maxillary arch (Table 2).On the antagonist arch, the majority (54.9%) of the patients wore full removable prosthesis, 17.6% wore transitional partial prosthesis and 5.9% presented a complete dental arch (Table 3).Unilateral or bilateral posterior edentulism accounted for 33.3% (Table 4).In the sample, 80.4% of the patients presented a healthy supporting mucosa (Table 5).The residual ridge resorption was at the stage 3 of Atwood scale for 74.5% of the patients (Table 6).

Discussion
The weakness of the sample related to the rate of recall can constitute a limit for this study.Vanzeveren et al. [11], brought back comparable rates of recall (40.3%) in studies carried out among patients rehabilitated by partial removable prosthesis.The sample size can be justified by incomplete telephone address of some patients and absence of motivation of others to take part of the investigation.
More than half of the sample is in good health at the moment of the study.Diabetes is the most frequent affection followed by cardiovascular diseases.The pathologies found among some patients and the long-standing polymedication by which they induce reduced the quality of supporting tissues, promote prostheses instability and take part in the failure of the rehabilitation [12].As for the cardiopathy requiring the infectious focus suppression, they cannot profit from the advantages of the under-prosthetic roots use which constitutes an adapted solution for the prevention of bone resorption, the comfort of patients and the psychological integration of overdenture [13,14].
A little more than half of the patients have prosthesis in upper arch.It appears that the maxillary arch is more concerned by removable prosthetic restoration than the mandibular.That is justified by the fact that the maxilla is more exposed to tooth loss because being more difficult to access for brushing and more exposed to trauma, and that the anterior edentulism presents more aesthetic requirement [4,15].The majority of the patients wearing the antagonist arch full removable prosthesis, and less than one patient out of five a partial removable prosthesis.The late support of oral diseases due to a defective oral health policy, and economic precariousness explain the high frequency of edentulism in the developing countries as well as the option of partial removable prosthesis instead of fixed prosthesis [4].
The high prevalence of total edentulism is related to the extraction of defective teeth to the detriment of the expensive preserving dental care.This therapeutic option is justified by a convergence of socio-economic factors among which late consultation of the patients, the low density of dental professional, the deficient technical platform and the scarcity of financial resources.Indeed, a positive correlation is found between the financial incomes of the populations and the consumption of dental care [3].
The third of the sample has posterior edentulism.According to Vanzeveren et al. [11], this kind of edentulism is more prone to prosthetic failures.Moreover, their rehabilitation can improve oral health-related quality of life [16].So, it is important to preserve posterior teeth on the arch or keep a molar root under the free-end saddle.If this clinical possibility is not acquired, a rational design of the framework is required to help to control the saddle movements and to obviate occlusal overload on the supporting tissues in order to ensure the prosthesis stability.
Whereas nearly one patient out of five in the sample presents a chronic inflammation of mucosa, Jaikittivong et al. [17], report symptoms of prosthetic stomatitis for one patient out of ten.The mucous lesions have a close correlation with the lack of information about the maintenance of prostheses and supporting mucosa.They are also related among patients affected by polyarthritis to the difficult control of the prostheses hygiene because of their defective dexterity.Moreover, the acrylic resin base plate constitutes a factor propitious to the development of Candida albicans [18,19].The suffering signs of the supporting mucosa are objective criteria of a treatment need.
An important bone resorption at the stage 4 of Atwood scale (low and round ridge) is observed among the quarter of the sample.A correlation may be established with the frequency of diabetes considering this affection weakens supporting tissues, thus accelerating the process of bone resorption.In addition, the wear of the plastic teeth occlusal surfaces involves the loss of the stabilizing contacts and a defect of the denture base adaptation.This prosthetic instability constitutes a factor worsening the bone resorption [20,21].Then, treatments by rebasing or relining become a pressing indication.

Conclusion
The affections of supporting tissues (bone and mucous) are inclined to increase the failure of the removable prosthesis rehabilitation.They can consequently constitute objective criteria of a treatment need.It appears more significant to introduce and organize recall procedures of rehabilitated patients for a better adaptation follow-up of their prosthesis.

Table 2 :
Distribution of the sample according to prosthesis location

Table 3 :
Distribution of the sample according to antagonist arch characteristics

Table 4 :
Distribution of the sample according to edentulism situation

Table 5 :
Distribution of the sample according to supporting mucosa status

Table 6 :
Distribution of the sample according to residual ridge resorption (Atwood classification)