Evaluating the Knowledge of General Dentist Towards the Management of Peri- Implant Diseases: A Multi-Center, Cross-Sectional Study

Background: Recently, implants have been widely considered as an option for replacing missing teeth. There are several biological conditions that must be considered for the success of an implant. Failure to satisfy any of these factors may result in complications, such as peri-implantitis or failure of the implant.


INTRODUCTION
Recently, implants are being widely considered as an option for replacing missing teeth. There are several biological presents progressive peri-implant bone loss beyond the initial physiologic bone remodeling that occurred following implant placement. In peri-implant mucositis, the lesion is limited to the peri-implant soft tissues and is diagnosed by the presence of bleeding on probing [2].
According to a study, the prevalence of peri-implantitis is one in four patients and of peri-implant mucositis is two in five patients. A recent meta-analysis on the epidemiology of periimplant diseases conducted by Jepsen et al. during the 11 th European workshop on periodontology shows the mean prevalence of 22% for peri-implantitis and 43% for periimplant mucositis [2].
Radiographs also are helpful in appreciating the extent of peri-implantitis. Along with the absence of peri-implant radiolucency, a mean Marginal Bone Loss (MBL) ranging from 0.9 mm to 1.6 mm throughout the first postsurgical year was established as a benchmark for implant success. A mean annual MBL ranging from 0.05 to 0.13 mm at the maintenance phase was recognized as another criterion for implant success [3,4]. There is also a lack of association between overload and peri-implant tissue loss in healthy conditions [5].
Management of peri-implantitis is done by the following methods, either individually or in combination. They include local debridement, surface decontamination of the implant, raising a surgical flap for cleaning and decontamination of the implant while trying to maintain and conserve the surrounding soft tissues and antimicrobial drugs. In case of retrograde periimplantitis, treatment options like surgical debridement of the apical part of the implant with/without the application of a bone substitute/Guided Bone Regeneration (GBR) procedure and the possible resection of the apical part of the dental implant are advocated [6,7].
It should be noted, however, that the local debridement of the implant should be done by instruments softer than titanium, such as: polishing paste with a rubber cup, interdental floss / brushes, or by using plastic scaling instruments [8].
There is very little available information regarding the attitude of a general dentist's towards the protocols used for the management of peri-implantitis. Therefore, the aim of this study was to evaluate the general dentist's attitude towards the management of per-implantitis diseases in Saudi Arabia.

Study Design
A multicenter cross sectional electronic based questionnaire was formulated based on the validated questionnaire from a previous study [9]. It was targeted towards the general dental practitioners in Saudi Arabia. The questionnaire was circulated from 3 rd April until 25 th May 2020.
The questionnaire consisted of 17 questions in total which were divided into 5 sections. The first section was about the demographic data such as the patient's age, gender, education level and clinical experience. The second section consisted of questions regarding the implant therapy training, while the third section was about the soft tissue assessment for periimplant. The fourth section dealt with peri-implant diseases. In this section, questions were aimed at evaluating the general dentist's knowledge of the mechanism of periodontitis and peri-implantitis and about the progression of the disease. The fifth and the last parts of the questionnaire were regarding the treatment plan of peri-implant diseases.

Ethical approval
The ethical clearance for the study was obtained from the ethical committee of the College of Dentistry, Prince Sattam Bin Abdulaziz University in Alkharj province, Riyadh, Saudi Arabia (IRB/PSAU2020017). All the subjects of the study took part voluntarily, and their anonymity was ensured. All the data collected were treated confidentially.

Data Collection
The study sample consisted of 721 general dental practitioners in Saudi Arabia, which included both male and female dentists. The exclusion criteria included all consultants, specialists or undergraduate students. The survey was constructed using survey monkey and distributed to the doctors via emails and social media. Emails were also sent via the Saudi Commission For Health Specialities (SCFHS) to all the registered General Practitioner dentists (GP) in Saudi Arabia. The questionnaire was prepared in English with clear instructions explaining the nature and the objectives of the study. Before distributing the questionnaire, a pilot study was initially conducted on 5 randomly selected general dentists to evaluate the understanding of the questions, choices and also to calculate the time needed to complete the study. It was concluded that there were no issues encountered with the pilot study and the time taken was around 3-4 minutes.

Statistical Analysis
The collected data was analyzed using Statistical Package for Social Sciences (SPSS, IBM, v. 21). Frequency distribution of demographic variables and participant responses to individual questions were calculated. Pearson's chi-square test was used for inferential statistical analysis with Holm's correction for adjusted p-value; the alpha at 95% confidence interval was 0.05 and all values below alpha were considered statistically significant.

RESULTS
A total of 721 subjects participated in this study. Participants were almost equally distributed as males and females with slightly more males (51.3%) than females (48.4%), and most of the participants had 1-5 years of experience: (71.7%). Table 1 depicts the demographic information of participants. The majority of the participants were 24-30 years old (73.1%) and the least number of participants were above 40 years of age (7.6%). Table 2 depicts the frequency distribution of participant's responses to individual questions. The majority had attended an implant training course (51.2%) while the rest had not (48.7%). Out of those who attended a training course, 26.1% said it was a short training course, 25.4% said it was provided by an academic organization, while the rest were trained by commercial courses or moderate training courses. Some of them (38%) did not take any training courses. Most participants (51.2%) agreed on the optimal efficacy of the training courses on peri-implantitis while (13.9%) disagreed. Some of the participants (13.5%) did not have an opinion on this. The majority of the participants (67.3%) thought they needed special instruments for the detection of peri-implantitis, but only 29.5% thought they do not need any special instruments for the intended purpose. When asked about the instrument usually used for measurement of probing depth of periimplantitis, most participants answered plastic probes (182, 25.2%), and the instrument least chosen was a titanium curette (3.7%). However, 37.2% of people thought the plastic curette was an ideal instrument for scaling the implant surface. Some of the participants (29.1%) had no idea about the ideal instrument for scaling and very few (4.6%) selected the stainless-steel curette. Most participants (79.3%) said they can identify and differentiate between normal and abnormal soft tissue around an implant, while 6.5% of the respondents could not. , The majority of the participants (70.5%), claimed to face complications such as failures and inflammatory diseases less than 5 times per year, while others (4.7%) said they face between 10 to 15 complications a year. More than half of the participants (54.8%) can differentiate between peri-implant mucositis and peri-implantitis, and 19.4% had no idea about this matter. Additionally, 52.7% knew the difference in the initiating mechanisms of periodontitis and peri-implantitis, while 19.6% had no idea. Furthermore, 40.9% of the participants knew the difference in progression time of periodontitis and peri-implantitis, but a significant number (34.3%) did not know this difference in progression. When asked about the classification(s) of peri-implantitis, the majority of the participants (53.7%) responded that there are 3 classes, and 7.1% said that there is only one class. The appropriate recall frequency for patients who received dental implants was thought to be every 1-6 months after the first year according to the majority of the participants (44.5%), every 1-2 months as per 7.6% of the participants and no recalls according to 3.9% of the participants. Amoxicillin-metronidazole was considered as the best and most effective antibiotic by the majority of respondents (76%), while only (5%) of dentists selected ciprofloxacin. Table 3 presents the results of the chi-square test that was done to determine whether any significant difference existed in the knowledge of participants with respect to age, gender and clinical experience. Whether or not participants had attended a training course (Q.4) differed statistically significantly among different age groups (p=0.003), between males and females (p=0.014) and between different years of clinical experience (0.009). When participants did attend a training course, the training course provider (Q.5) differed significantly with respect to age (p=0.006) and clinical experience (p<0.001). The knowledge of instrumentation for measuring probing depth (Q.8) also differed significantly with respect to age (p<0.001) whereas the knowledge of instrumentation for scaling the implant site (Q.9) differed significantly with age and gender (p<0.001 for both). Similarly, knowledge of peri-implant classifications (Q.15) differed significantly with respect to age (p=0.013) and gender (p=0.007). Lastly, knowledge about progression time of periodontitis and peri-implantitis (Q.14) different significantly with respect to age only (p=0.045). There was no significant difference in responses to other questions with respect to any variable.

DISCUSSION
One topic of major interest in contemporary dentistry is the biological complications that are associated with dental implant therapy. These complications are usually inflammatory in nature coupled with bacterial challenges [10 -12]. There are two clinical varieties that are commonly identified; periimplant mucositis and peri-implantitis. Both diseases have an inflammatory lesion in the peri-implant mucosa, but the latter is characterized by progressive bone loss too [13]. Furthermore, many features are common between periimplantitis and chronic adult periodontitis. This makes it important for dental implant practitioners to have knowledge about peri-implantitis in order to properly identify and manage these implant related complications.
This study population consisted of an almost similar proportion of male and female dentists which is similar to the study conducted by Tripathi et al.. Most of the participants included in this study had attended an implant training course (51.2%) and most of them had received this training either in an academic setting (25.4%) or from private course providers (26.1%). Only 21.5% of the participants strongly agree that the training provided was optimum, while the majority (51.2%) agree that the training was optimum. Studies have reported that a combination of clinical, didactic and simulation training is more effective in producing confidence and necessary skills among pre-doctoral students [14]. It is yet to be conclusively determined if the type of setting where training was received has any effect on knowledge. In our present study, the difference in knowledge was statistically significant among different training settings with respect to age, gender and clinical experience. In a similar study by Kadkhodazadeh et al. (2017) [9], majority of the participants had received dental implant training (97%) from an academic setting (61.8%) and agreed that they received optimum training (44.7%).
The majority of the participants in our study (67.3%), believed that a special instrument is required for probing in peri-implantitis, with the most participant's choosing a plastic probe (25.2%) followed by a stainless-steel probe (23.7%) and most (37.2%) believed that scaling of an implant surface must be carried out with a plastic curette. Prataptharajan and Suresh (2012) [6] recommend using a rigid plastic probe to measure probing death. It was earlier believed that stainless steel probes may further damage the already frail periodontal tissues in an infected implant site, but the Consensus Report of the Sixth European Workshop on Periodontology (Lindhe et al. 2016) [13] clarified that probing using a conventional stainless-steel probe with a light force of 0.25N does not damage either the mucosa or the implant. In addition, Farkhavar et al. (2012) [15] conducted an in-vitro study to test the effect of probes and scalers made of both metal and plastic on implant abutment surfaces. The study found that plastic probes produced surface roughness of the implant while metal probes did not. Other studies have shown that out of different oral hygiene instrumentations and methods like hand scaling with metal and plastic scalers, ultrasonic scaling with metal tips, weekly rubber cup polishing, air polishing, and daily brushing, rubber cup polishing with daily brushing produced the smoothest implant surfaces while plastic scalers performed better than metal scalers [16 -18]. Some studies also recommend carbon fiber curettes and titanium curettes [7,19,20].
Most participants in our study could differentiate between a normal and abnormal tissue (79.3%), between peri-implant mucositis and peri-implantitis (54.8%), between the initiating mechanisms of peri-implantitis and periodontitis (52.7%), and between the progression times in periodontitis and periimplantitis (40.9%). This displays that more than half of the participants can identify peri-implantitis from other similar infections. This is important as the first step in managing any disease is proper diagnosis. There are several parameters that are used to define the onset, extent and severity of periimplantitis that help in its diagnosis. These include radiographic bone loss, probing depth, bleeding on probing, and suppuration. Mombilli et al. (2012) [21] defined the typical bone loss around implants to be a strictly demarcated, craterlike defect without any notable signs of implant mobility. Since mobility denotes complete failure of the implant, the American Academy of Periodontology does not regard mobility as a diagnostic parameter and recommends the removal of the failed implant. There is no bone loss in peri-implant mucositis, which is the most distinguishing factor of peri-implantitis and periimplant mucositis.
Lastly, there have been reports on the use of different kinds of antibiotics in conjunction with non-surgical and surgical mechanical debridement for the treatment of both chronic and aggressive periodontitis such as tetracyclines, doxycycline, penicillin (amoxicillin), metronidazole, macrolides (spiramycin, erythromycin, azithromycin), clindamycin and ciprofloxacin. A combination of amoxicillin and metronidazole is the most commonly reported combination therapy for the treatment of periodontitis [21,22]. These aforementioned antibiotics have also been reported to be used for the management of peri-implantitis with the addition of ornidazole and azithromycin [23 -26]. However, the significance of adjunctive antibiotic therapy in the treatment of peri-implantitis is controversial [24] and there is a lack of adequate research on the effectiveness and clinical advantages of the use of systemic antibiotics as part of the standard mode of peri-implantitis management [27,28]. This precludes the need to conduct more randomized clinical trials to conclusively establish whether antibiotics help as adjunctive management strategies to clinical debridement. In our study, most participants (76%) chose the amoxicillin-metronidazole combination therapy as the most effective method to treat peri-implantitis, which is in line with reported literature [23,24].
This study provides some important insights into the knowledge of dentists in Saudi Arabia regarding the management of peri-implant diseases. The surveyed participants seem to possess adequate knowledge in some questions and less than adequate knowledge in some other questions. To the best of the author's knowledge, this is the first multi-centre study done from the region involving a large sample and adds valuable information to literature that can be used by policy makers, course creators and academics teaching dental implant therapy in Saudi Arabia. As with all crosssectional studies, response bias could be a limitation of this study.

CONCLUSION
This study concludes by suggesting that most of the participants have adequate knowledge about peri-implant soft tissue assessment, mechanism of periodontitis and periimplantitis, its initiation and progression, along with its management. Most of the participants found the training courses on peri-implantitis to be efficient. It is recommended to conduct more courses and studies that would aim at understanding the pathogenesis, etiology, diagnosis, and treatment of peri-implant diseases so as to increase awareness among dentists.

ETHICS APPROVAL AND CONSENT TO PARTICIPATE
The ethical clearance for the study was obtained from the ethical committee of the College of Dentistry, Prince Sattam Bin Abdulaziz University Alkharj, with reference number (IRB/PSAU2020017).

HUMAN AND ANIMAL RIGHTS
No animals were used in this research. All human research procedures followed were in full accordance with the ethical standards of the committee responsible for human experimentation (institutional and national), and with the World Medical Association Declaration of Helsinki of 1975, as revised in 2008.

CONSENT FOR PUBLICATION
A written consent to publish this information was obtained from all the participants for publication of this study.

STANDARDS OF REPORTING
STROBE guidelines were followed in this study.

AVAILABILITY OF DATA AND MATERIALS
The data that supports the findings of this study are available at reasonable request to the corresponding author.

FUNDING
None.