In order to provide anchorage, many apparatuses were produced and used in orthodontics [6,7]. Among these, orthodontic mini-screws are today, the anchorage units often preferred . Orthodontic mini-screws are open to infection due to their presence in oral microbiota. Poor hygiene of the area of the mouth where mini-screw is applied may cause inflammation between the mucosa and the screw head, which may proceed to the end of the mini-screw and lead to peri-implantitis and, thus, the loss of the mini-screw [12,13]. Long-term maintenance is very important to reduce mini-screw losses . In many studies, the ways of providing hygiene around the mini-screw and naturally reducing the loss of mini-screw have been investigated [9,11,14,15,17-20]. Poor oral hygiene has been shown as one of the important risk factors causing mini-screw losses [14,15,21-23]. Studies have shown that failed mini-screws have a microbiota similar to the one encountered in periodontal diseases [24-26]. In addition, it has been found that in the literature, studies investigating the microbiota around the orthodontic mini-screw are limited. There are many studies investigating the microbiota around the mini-screw, but there were no studies investigating the effects of different antiseptic mouthwash on this microbiota. Therefore, this study aims to investigate the effects of different antiseptic mouthwash on the microbiota around the mini-screw applied to patients undergoing fixed orthodontic treatment.
Patients receiving orthodontic treatment cannot achieve the same optimal hygiene only by brushing their teeth, as in individuals not under such treatment . As orthodontic apparatuses such as bands, braces and mini-screws create areas of plaque accumulation that feed bacteria , oral hygiene cannot be maintained due to plaque accumulation caused by elastics and ligatures used . In the literature, brushing the head of the mini-screw with a soft brush , cleaning the head of the mini-screw with sterile water , using mouthwash  and antibiotic treatment  are some of the methods used to ensure the hygiene of mini-screw area. However, giving antibiotics to a person without any other disease just to ensure oral hygiene is a matter of debate.
In the studies carried out, the use of chlorhexidine-containing antiseptic mouthwash - which is also used by one of the groups included in our study - was recommended for patients undergoing orthodontic treatment [29-31], and for infected areas, chlorhexidine-containing mouthwash was recommended for 5-7 days . Chlorhexidine demonstrates its antiseptic activity by allowing the precipitation of phosphate-containing molecules in the bacterial cell membrane . Although chlorhexidine-containing mouthwash is a successful agent in preventing infections, in long-term use, it has been reported that chlorhexidine may cause discoloration of the tongue and teeth [33-35], taste changes in mouth [33,34,36], and desquamation and irritations in the soft tissues of the mouth [33,37-40]. E. O. containing mouthwash used by another group in our study are formulated by mixing essential oils with menthol, thymol, eucalyptol and methyl salicylate. They demonstrate bactericidal effect by denaturing porins in the bacterial cell membrane and leaking low molecular weight molecules in cytoplasm out of the cell . In a study, the efficacy of E.O. containing antiseptics against a broad spectrum of bacteria was demonstrated, but it was reported that the oral microbiota was suppressed in the first hours after application . Chemotherapeutics containing E.O. and chlorhexidine are effective even against bacteria embedded in the biofilm by penetrating into the biofilm layer [43-45]. Antiseptics containing substances such as manuka oil and tea tree oil that are in the E.O. group have been reported to have bactericidal effects against peri odontogenic and cariogenic bacteria such as P. gingivalis and S. mutans , prevent plaque formation and gingivitis , and it has also been reported that Listerine mouthwash containing E.O. used in patients undergoing orthodontic treatment causes a significant decrease in MPI and MGI [48,49] and may be recommended for patients undergoing orthodontic treatment . The 7.5% Povidone-iodine which is the antiseptic mouthwash used by another group in our study is the most commonly used iodine derivative antiseptic. At a concentration of 1/200.000, it kills all vegetative forms of bacteria within 15 minutes. They demonstrate effective bactericidal, fungicidal, virucidal and sporicidal effects even at low concentrations. They cause high irritation and staining [50-52]. They demonstrate bactericidal effect by affecting the main protein groups, nucleotides, and fatty acids by disrupting the electron transport of iodine aerobic microorganisms penetrating into the microorganism cell wall with an oxidative effect .
The sterile paper point that we use to collect microbial samples is used in endodontic treatments in dentistry and in the collection of biological samples in small areas in medicine. In a study whereas biological sample was collected with a paper point, it was stated that the paper point showing the number of bacteria in the test medium most accurately was ISO 45 and that 30- or 60-second periods can be used for sample collection . In another study where sample was collected from the mini-screw area, ISO 35 paper point was used . However, this study did not mention in how many seconds the samples were taken. In another study carried out in the mini-screw area, ISO 45 paper point was used and this study also did not mention in how many seconds the samples were taken . In the preliminary clinical evaluation before our study, it was observed that the paper points numbered 45 and 40 caused bleeding in the mucosa, and that the paper points 30 and below could not remain stable for 30 seconds and dropped due to the liquid absorbed. Considering all these reasons, sampling time was determined as 30 seconds and ISO 35 paper point was chosen for sampling.
Streptococcus bacteria are the most common bacteria encountered in the studies investigating the microbiota in the mini-screw area [19,20,55]. This may be due to the fact that these bacteria are also present in the normal oral microbiota. In our study, among the 12 species of microorganisms detected, 7 of them were streptococcus. In this respect, the results are similar to the literature. In our study, 6 different growth mediums were used to detect all bacteria that can be cultured. The aim was to produce the maximum number and variety of microorganisms possible. Cultivation and detection of such a wide spectrum of microorganisms is one of the superior aspects of the study.
The effects of different antiseptic mouthwash on microbiota around the mini-screw applied to patients undergoing fixed orthodontic treatment were investigated in this study and the following results were obtained:
- Brushing teeth only is not sufficient to maintain hygiene and reduce microbiota around the mini-screw in patients undergoing orthodontic treatment.
- Antiseptic mouthwash containing 0.12% Chlorhexidine, Essential oils (E.O.) and 7.5% Povidone-iodine were found to be successful in reducing the microbiota around the mini-screw.
- In order to avoid the undesirable effects of these agents, it is considered that more comprehensive studies should be done clinically with larger patient groups in order to see the effects of combined use at different times and periods.