The well-being and quality of life are often affected by the common oral changes and conditions of the individuals. The loss of natural teeth is a health problem that is associated with functional, cosmetic, psychological morbidities and disabilities in daily living activities such as impaired eating and speaking, or social embarrassment. Various attempts have been made to replace the lost dentition with artificial teeth (prostheses) that resemble the natural teeth in function and appearance. Fortunately, restoration of missing teeth with dental implants offers far-reaching solution to the problems   .
A dental implant is an artificial root inserted in the jawbone, which restores a lost tooth so that it looks, feels, and is fit like a natural tooth   .
The dental implant treatment is considered to be the best treatment option for single or multiple missing teeth. It is estimated that one million implants are placed in the world yearly  .
Due to the high success rates and predictability of dental implants, their prevalence in the oral rehabilitation is increasing year by year   . In addition implants offer alternative treatment options to fully or partially edentulous patients. A majority of patients treated with implant supported prosthesis have reported improvement in their quality of life, assurance, self-confidence including psychological benefits and moreover conservation of the tooth structure adjacent to the teeth to be replaced   .
Little information is available to patients regarding dental implant and its success. This problem is more encountered in developing nations where there is a lack of education and awareness among people about dental implants as a treatment modality. Therefore, complete information on implant treatment must be provided to guide the patient in the choice of the most appropriate option  .
To the best of our knowledge, there is no existing literature regarding the awareness of patients about dental implants in D.R. Congo.
Therefore, the aim of this study was to assess the awareness about dental implants as an alternative treatment among Congolese patients.
・ Selection of the study population and questionnaire
A cross-sectional study was conducted in two institutions namely, CBCO Bandal and Ngaliema Clinic, from August to December 2017. A convenient sample size of 450 respondents agreed to participate to the survey. Their age varied between 18 to 92 years old. The mean age was 35.43 ± 12.94 years. They were selected during their regular visit in the dental services of the two institutions above cited.
To be part of this study, the patient has to accept voluntarily to participate and to be aged 18 years old at least.
The study was approved by the local ethics committee of the University of Kinshasa.
A printed questionnaire comprised of 20 questions in order to evaluate patient dental awareness was given to them. Questionnaire was prepared in French and explained in Lingala (local language) to all participants.
All the respondents were informed about the aim and objectives of the study. Questions used in the survey form included self-explanatory questions which were adapted from a previous study conducted by Tomruk et al.  .
・ Statistical analysis
The collected data were entered in Microsoft Excel 2010 and analyzed by Statistical Package for Social Sciences (SPSS 20.0, Chicago, IL, USA) software.
The age of the majority of patients varied between 30 to 50 years old. The majority of them (62.2%) had a high education level (university and above). The female participants represented 63.6% whereas the male, 36.4% (Table 1).
Out of 450 patients interviewed in this study, no one had undergone an implant therapy whereas 6.7% were denture carriers (Table 2).
Regarding the alternatives for replacing teeth, 41.5% of patients interviewed were aware of partial removable denture; 28.4% were aware of fixed partial denture whereas only 14.4% were aware of dental implant as an alternative to replace missing teeth (Table 3).
Regarding the assessment of the information level of dental implants, 1.6% reported that they were very well informed, 3.1% were well informed and 31.1% were poorly informed subjectively (Table 3).
Seventy one percent didn’t know the advantages of non-removable denture vs removable denture, 5.5% reported that it was “less annoying in the mouth”, 17% said “more esthetic”, 5.5% thought “not like a foreign body”, 1% reported “feel like natural teeth”. The high cost was the main disadvantage of dental implant (23%) (Table 4).
Regarding the anchor of dental implants, 8% reported that it was in the jaw bone, 6% answered that it was in the gingiva.
When asked about the lifelong of implants, 0.4% answered >5 years, 0.2% said >10 year, 1% reported >20 years and 6% answered for lifetime (Table 5).
When the patients were asked about the information sources of dental implants, results reported, dentist (5%), friends (2.6%), media (5.5%), medical doctor (0.7%) (Table 6).
About the expectation of informations on dental implants, 88.4% wished to get information of dental implant near the dentist, friends (1.6%), media (2.4%), medical doctor (6.9%) and other (0.31) (Table 7).
Table 1. Sociodemographic profile of respondents.
Table 2. Questions on knowledge and dental situation.
Table 3. Questions on alternative teeth replacement.
Table 4. Questions on advantages and disadvantages of different dentures.
Table 5. Questions on anchorage and lifelong of implants.
Table 6. Questions on the sources of information about alternatives for replacement of teeth.
Table 7. Questions on expectations about the source of information.
The objective of this study was to assess the awareness level of patients about dental implant as an alternative treatment for oral rehabilitation. In the recent decades, dental implant has become a popular treatment option in most developed countries.
This survey revealed that no respondent had undergone implant therapy while 6.7% of patients were prostheses carrier. These results could be explained in the one hand, by the high cost of oral implant rehabilitation and low income of the population  , and in the other hand by the lack of implants equipment in most hospitals of Kinshasa city.
The awareness of dental implants as an alternative treatment was low with 14.4%. This level of awareness suggests that most of patients attending dental services are not informed about dental implant as an alternative treatment for oral rehabilitation. This argument is important to be mentioned as the number of participants with high level of education (university and above) was high. Therefore, a great work of information have to be done near them. Another low level of awareness was reported in a survey conducted by Mgbeokwere et al. 2011  in the Nigerian population (9.7%). However, studies done by Zimmer et al. 1992  in the USA, Berge (2000)  in Norway, Suprakash et al. 2013  in India, Kohli et al. 2014 in Malaysia  reported higher level of awareness either 77%, 70.1%, 77%, and 72% respectively.
Only 1.6% of patients estimated that they were very well informed about dental implants and 15.3% very well informed about alternatives for replacing teeth. Therefore, patients should be highlighted about different treatment modalities for replacing missing Teeth.
Seventy one percent of respondents didn’t know the advantages of non-removable vs removable dentures. These results suggest that dentists have to be more involved in conveying explicit information to patients about different types of dentures and their eventual advantages and disadvantages.
In this survey, the major disadvantage about dental implants as estimated by the participants was the high cost (23%). This point of view is similar to that of several authors from different countries, developing as well as non developing       .
In the present study, 86% didn’t know where implants are anchored; only 8% stated the jaw bone. This result confirms the lack of knowledge about dental implants among patients mentioned above. In a study conducted by Suwal et al.  , 24.5% stated that the jaw bone was the site of anchorage of the dental implant. The majority of respondents (92.4%) were unaware about the durability of dental implants, 1% thought the lifelong as > 20 years, 6% for lifetime. Therefore, patients should be more informed properly about the implant therapy. Unrealistic estimates and expected implant survival time should be cleared up properly before the treatment to prevent misunderstandings and misinformation  .
Regarding the sources of information about dental implants, two main sources were reported; 5.5% were informed via media, 5% by dentists. These results corroborate with the study of Zimmer et al.  . However, Bhoomika et al.  , Kholi et al.  , Kumar et al.  , Esfahani et al  , Deeb et al.  reported that the main source was the dentist while Suwal et al.  , Al-Johany et al.  reported relatives and friends.
When asked about the expectation on sources of information, the majority (88.4%) of patients wished to get information about dental implants from their dentists. These results are in agreement with the study conducted by Tomruk et al.  . Dentists As this survey was performed in a limited group of patients, further surveys are needed to take place in a larger population.
As a main shortcoming, this survey was performed in a limited group of patients not randomly selected; future surveys are needed to take place in large samples of the population selected randomly.
The present study showed that no respondent had undergone implant therapy, patients awareness towards dental implants as an alternative treatment for replacing missing teeth was low. Media and dentists were the main sources of information regarding dental implants among all patients. The major disadvantage of implant as a treatment option was the high cost. Therefore, awareness of dental implants among people should be improved; dentists should be the first line for carrying realistic information. A need for the equipment of hospitals and education of dentists in this field is paramount.