There was a wide variation in the type, dosage and duration of prophylactic antibiotic usage in conjunction with dental implant placement both in simple and complicated cases where bone augmentation was required. The results showed that the majority of dentists routinely prescribed prophylactic antibiotics prior to dental implant surgery. This finding is in agreement with other studies where 72% - 85.5% of the surveyed data, from Finland, India, the USA and the UK, routinely prescribed prophylactic antibiotics in conjunction with implant insertion (Datta, et al. 2014; Deeb, et al. 2015; Froum and Weinberg 2015; Ireland, et al. 2012; Pyysalo, et al. 2014). While the dentists’ survey concluded that they were influenced by scientific reviews, the results extracted from patients’ medical charts reported that the majority were treated with antibiotic doses, durations and types differing from that recommended by the national guidelines. One explanation is that the dental practitioners were more cautious and precise when answering the questionnaire but in practice they do not always follow clinical guidelines. In addition, investigators have recently discovered that dentists do not always keep themselves updated, despite the availability of information (Oberoi, et al. 2015; Palmer and Batchelor 2004). Even so, with scientific evidence regarding the use of prophylactic antibiotics in conjunction with implant surgery still inconclusive, the available information does not
provide the clinician with clear guidance. It may also be that the clinician, under certain circumstances, may prescribe antibiotics to protect the patient, and themselves, from treatment complications and any resulting financial consequences (Wardh, et al. 2009).
In the results for both Studies II and IV, there was a significant increase in the number of patients treated without antibiotic prescription prior to dental implant treatement between the two time periods. This may either be due to the lack of solid evidence regarding the benefit of prescribing antibiotics to decrease the risk of postoperative infection/ implant failure, or that the dentists’ knowledge increased regarding the undesirable effects of the antibiotics they had been prescribing and they became more cautious.
The more conservative approach to antibiotic prescription prior to dental implant placement was observed in the questionnaire filled in by dentists with postgraduate clinical training.
Moreover, in the other study (Study IV) there was a significant but weak relationship between the dentists under residency training and restrictive antibiotic prescription. This may be due to dentists’, either under residency training or who had completed their training programmes, clinical training which focused on both the benefits and the undesirable effects of antibiotics.
In a study testing the effect of a short-term antibiotic educational programme on dentists’
behaviors, promising results regarding antibiotic usage were shown (Öcek, et al. 2008).
On comparing the two time periods, there was a noticeable change in the type of antibiotic prescribed as reported by the dentists’ questionnaire (Study II). Amoxicillin became the preferred drug of choice. Thus can be clarified by the implementation of the scientific reviews and recommendations that favour the prescription of amoxicillin preoperatively. Amoxicillin is widely used in conjunction with dental implant surgery, and its effect on reducing the risk of implant failures has been studied (Dent, et al. 1997; Laskin, et al. 2000). It has a good coverage of the oral microflora, moderate oral and gastrointestinal ecological effect, rapid and extensive oral absorption and therefore is a suitable choice for antibiotic prophylaxis in oral surgery. In the other study (Study IV), the patients’ medical charts show that the majority of the bone augmentation procedure patients took penicillin-V. In dentistry, penicillin-V is a widely prescribed and has several beneficial characteristics. It has a bactericidal action with a narrow spectrum, it is effective against most Streptococcus species and oral anaerobes, and it has a mild to moderate ecological effect when used to treat dental infections (Lund, et al. 2014;
Resnik and Misch 2008).
A change in antibiotic prescription duration was observed between the two time periods in the studies, reflecting the effect of the scientific reviews and national recommendation. More than
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half the surveyed dentists reported that they prescribed a single preoperative dose post guidelines, rather than an extended regimen. Moreover, in the present study on bone augmentation surgery prior to dental implant placement, there was a dramatic reduction of the length of prophylactic antibiotic treatment. This could reflect the efforts to reduce antibiotic prescription as the clinician might not feel confident to refrain totally from extended prophylaxis. Therefore, this issue is still contradictory, with the need for providing recommendations based on sound scientific evidence. While great effort has gone into improving the guidelines in Sweden, solid information is still lacking. However, changing dentists’ antibiotic prescription behavior requires time. Therefore, a follow-up study is mandatory to check the influence of these recommendations and to remind practitioners to secure a professional attitude when prescribing antibiotics.
The positive relationships between using resorbable membranes, sinus lift procedures and antibiotic prescription reported in the current bone augmentation study, to our knowledge, have not been observed in previous studies. The infection rate associated with these procedures is considered infrequent (Testori, et al. 2012). However, in a study that published a clinical consensus and recommendations for sinus lift procedures, the use of antibiotic prophylaxis for 7 days to reduce the risk of infection was favoured (Testori, et al. 2012). Moreover, the present study reported that increasing the number of treated edentulous areas will increase the number of restrictive, no antibiotic prescriptions by dentists. Inserting several implants requires a larger mucoperiosteal flap, prolonged operating time, and poses a higher risk for wound contamination (Figueiredo, et al. 2015). Explanations for our results could be that a dentist placing more than three implants is more confident with their surgical and aseptic techniques than other dentists performing single implant surgery, or this may just be a coincidence, or due to the small number of cases. Therefore, there is a need for further RCT to determine the reasons behind the influencing choice for antibiotic prescription. This would also form an important base for motivating dentists to be restrictive.
Five percent of the patients who performed bone augmentation procedures prior to dental implant placement developed postoperative infections. In the current study, patients who were not treated with antibiotics had a weak significant relationship with the development of postoperative infection. This is probably due to the fact that this kind of surgery (clean-contaminated surgery) carried a risk of infection, but this risk can be reduced with the use of prophylactic antibiotics (Olson, et al. 1984; Peterson 1990). However, since the rate of infection is low in relation to the sample size of the study, larger clinical studies are required to
confirm this result. To date, there is no gold standard for the treatment of postoperative infections, and thus probably explains the difference in dealing with this situation among implant surgeons.
The majority of the dentists surveyed reported a need for the national guidelines to determine the need of antibiotics in implant surgery. The implementation of practice guidelines is expected to improve antimicrobial treatment behaviors, and reduce infection rates (Foucault and Brouqui 2007). Thus, strong scientific evidence are mandatory in the area of implant dentistry. It should be kept in mind that guidelines for antibiotic selection should be modified according to local factors, such as local resistant bacteria status, and professional realities (Mainjot, et al. 2009).
5.3 ANTIBIOTICS AS A PROPHYLAXIS IN IMPLANT DENTISTRY WITH BONE