Introduction

Today, satisfying results are obtained in an aesthetic and functional sense with dental implant-supported prosthetic approaches (1). However, it is possible to encounter biological complications affecting the tissues around dental implants even in cases of successful osseointegration.

Serum osteocalcin has been shown to be a bone turn-over marker and a clinical diagnostic marker of metabolic bone diseases (2). Kunimatsu et al. (3) showed that no significant amount of osteocalcin was detected in gingivitis whereas osteocalcin levels increased in periodontitis.

Lasers can provide positive outcomes in the treatment of peri-implantitis, since it effectively reaches implant surfaces that cannot be accessed by using mechanical methods and removes the tartar and has bactericidal effects (4). Laser therapy can further contribute to the decontamination of peri-implant tissues, the development of regeneration and healing (5).

In light of all this information, the hypothesis of our study was laser monotherapy provides less improvement in clinical parameters in smokers with peri-implantitis compared to non-smokers with peri-implantitis. This study aimed to evaluate the effect of various laser systems on clinical parameters and peri-implant osteocalcin levels in smokers and non-smokers with peri-implantitis.

Materials and Methods

This study was prepared in accordance with Consort 2010 guidelines (Figure 1). This study was designed as a randomized, prospective, and single-blind clinical trial. Individuals who applied to Kırıkkale University Faculty of Dentistry Department of Periodontology were included in the study. The study was performed in accordance with the principles of the Declaration of Helsinki and was approved by Kırıkkale University Clinical Research Ethics Committee (09/02) and the Turkish Medicines and Medical Devices Agency (2019/060). Prior to the study, all individuals to be included in the study were given detailed information about the purpose and the method of the research and informed consent forms were obtained.

Study Groups

A total of 103 implants with peri-implantitis in 42 participants were included in the study: 20 implants of smoking patients undergoing Er:YAG, 15 implants of non-smoking patients undergoing Er:YAG, 19 implants of smoking patients Er,Cr:YSGG laser application, 15 implants of non-smoking patients undergoing Er,Cr:YSGG, 18 implants of smoking patients undergoing diode laser application, and 16 implants of non-smoking patients undergoing diode laser application. Twenty eight participants who did not meet the inclusion criteria were excluded from the study. Simple randomization method was used in the study. Randomization was provided by draw up.

The inclusion criteria were as follows:

1. Presence of a pocket at probing depth of ≥4 mm in at least one implant

2. No mobility of the implant

3. No systemic disease that could affect the outcome of treatment

4. No systemic use of antibiotics in the last six months

5. No peri-implantitis treatment in the last three months

6. Individuals between the ages of 30-60 years.

The exclusion criteria were as follows:

1. Individuals who did not consent to participate in the study

2. Subjects receiving radiotherapy

3. Persons consuming alcohol

4. Presence of pregnancy and lactation

5. Individuals with parafunctional habits such as teeth grinding or bruxism.

Peri-implantitis was diagnosed with the presence of pocket in probing depth of ≥4 mm, radiographic bone loss of >2 mm, bleeding on probing (BoP), and suppuration (present or not) (6). Individuals who smoke at least 10 cigarettes daily for at least 5 years and more are considered to be smokers (7). Groups were created as follows:

Group 1: Smokers treated with a diode laser; Group 2: Smokers treated with an Er,Cr:YSGG laser; Group 3: Smokers treated with an Er:YAG laser; Group 4: Non-smokers treated with a diode laser; Group 5: Non-smokers treated with an Er,Cr:YSGG laser; Group 6: Non-smokers treated with an Er:YAG laser.

Clinical Measurements

Before the laser applications, clinical periodontal parameters including sulcus depth (SD), clinical attachment level (CAL), suppuration, modified plaque index (mPI), gingival index (GI), mSBI and keratinized mucosa measurements were obtained from all implants and implant sulcus fluid (PISF) was collected. Re-evaluation was performed at the 6^th month. The changes in SD and CAL were the primary outcome of this randomized trial and as well as the secondary variables GI, mPI and modified sulcus bleeding index (mSBI). Pressure was applied to the mucosa to determine whether there was an inflammatory flow. It was evaluated dichotomously. All clinical measurements were recorded with a standard, color-coded, discontinuous, pressure calibrated plastic periodontal probe (Click-Probe Blue, Kerr GmbH, Biberach, Germany). All measurements were done by the same examiner (K.B.).

Concentration (ng/mL) = Osteocalcin value x Amount of Dilution (0.2 mL)

PISF volume

Total amount (ng/site) = Osteocalcin concentration x PISF volume (mL)

site (2)

Peri-implantitis Treatment Procedure

After the baseline measurements, patients received treatments (K.B.), the diode laser (Epic10, Settings: 940±10 nm, 2.5W, CP2 mod) was applied for 30 seconds using a 400-µm-thick fiber tip (E4 7 & 9 mm). The laser tip was applied as vertical and horizontal scan along the subgingival implant (8). The procedure was carried out on day 0, 7 and 14.

Pockets were treated using an Er,Cr:YSGG laser (Waterlase, Settings: 1.5 W power, 30 Hz, Water 50%, Air 40%, 50 mJ/pulse, 140 µs pulse duration) by inserting a 14-mm long, 500 µm diameter radial firing tip (RFPT5) into the pocket. The tip was placed at the bottom of the pocket and kept at an angle parallel to the long axis of the implant and epithelial tissue as much as possible. After contact with bone, the tip was slightly retracted and moved up and down in the pocket in the apical-coronal direction with a slow sweeping motion and the buccolingual or mesiodistal direction, depending on the location of the pocket (9).

Er:YAG laser [Fotona, Settings: 100 mJ/pulse (12. 7 J/cm²), 10 pps, pulse energy of the tip was about 85 mJ/pulse] was applied to the implant surfaces under irrigation using a conical glass fiber tip (R14 CD FIBER TYPE, TAPER 12/0.6). The fiber tip was applied parallel to the implant surface in contact mode or a circular motion from the coronal to the apical direction for 60 seconds with an opening of 10-15 degrees (6).

Statistical Analysis

Power analysis calculations displayed a minimum requirement of 66 samples per group in order to compare data at a=0.05 with a power value of 95%. The statistical significance level in the study was determined as p<0.05. Statistical analyses were performed by using IBM SPSS Statistics 22.0 and MS-Excel 2016.

Results

Age and gender distribution of the participants are shown in Table 1. When the sixth-month measurement results were evaluated, it was determined that there was a significant difference among the groups in terms of SD, CAL, mPI, GI and total amount results. Post-hoc test showed that the GI value of patients in the Er,Cr:YSGG laser group was significantly higher than the other groups (Chart 1).

The initial values of the diode laser group revealed that the amount of mPI, concentration and total amount were significantly different in the smoker and non-smoker groups. It was determined that these measurements were higher in the non-smoker group and lower in the smoker group. As a result of the six-month evaluation, the concentration of osteocalcin was found to be seven times higher in the smoker group than the non-smoker group and the difference was also significant in the total amount results (Table 2).

There was a significant difference between the Er,Cr:YSGG laser group and other groups in terms of GI values. The difference in GI was found to be caused by the smoker group which had higher median value. In other clinical measurements, the results in the groups were similar. There was a significant difference between the groups in terms of the six-month total amount. When the clinical evaluation results were examined, there was a significant decrease in sixth-month measurements in all evaluation results (Table 3).

Discussion

It is a very important fact that peri-implant diseases are increasing as implant applications increase. In our study, Er:YAG, Er,Cr:YSGG, diode laser were applied as monotherapy in the treatment of peri-implantitis and clinical measurements such as mPI, GI, SD, CAL, mSBI were observed to decrease significantly. Biochemically, a significant decrease in concentration and the total amount of osteocalcin were observed. The decrease in the total amount was higher in diode laser group than in the other groups.

A meta-analysis examining the relationship between smoking and peri-implantitis shows that smoking can change treatment outcomes in peri-implant diseases (10). In our study, when the smokers and non-smokers in diode laser group were compared according to the initial and six-month results, CAL was found to be significantly higher in the S- group than in the S+ group. The concentration and the total amount of osteocalcin decreased nearly 6 times in the non-smoker group.

Decontamination in peri-implant disease includes mechanical debridement, chemical debridement, laser, antimicrobial photodynamic therapy issues (11). In a study that the efficacy of diode laser as a supportive option to the conventional non-surgical treatment of peri-implant mucositis and initial peri-implantitis are analyzed, twenty-three patients were evaluated and pointed out that diode laser could be used as an adjunct to the conventional non-surgical treatment of peri-implant mucositis and peri-implantitis (12). Mettraux et al. (8) used diode laser in addition to mechanical debridement in their study. In the 2-year follow-up, a significant decrease was observed in SD, BoP, and radiographic bone filling was observed. Al-Falaki et al. (13) evaluated the treatment outcome at 2 and 6 months following the use of Er,Cr:YSGG laser in the non-surgical treatment of peri-implantitis. A significant decrease in BoP was observed in the depth of the sulcus and in almost all areas of application. The surface of the implants removed due to peri-implantitis was examined by electronic and microscopic methods. It was observed that almost all of the surfaces of the implants treated with the Er,Cr:YSGG laser are decontaminated (14). Schwarz et al. (15) compared the Er:YAG laser application with mechanical debridement using a plastic curette. The decrease in SD revealed a statistically significant difference in both groups at 12 months. Only BoP values decreased statistically at 24 months, while CAL and BoP decreased significantly at 12 months in both groups. When we evaluate according to clinical parameters in our study, it is seen that three lasers are successful. However, when looking at the change in the total amount, it was observed that there was a 6.99-fold decrease in the diode laser group, 2.45-fold decrease in the Er,Cr:YSGG laser group, and 2.43-fold decrease in the Er:YAG laser group between the initial and the 6^th month samples. The limitations of our study are the evaluation of smoking according to the information given by the patient and the lack of serum osteocalcin levels.

Conclusion

This study is a unique clinical study in its field in terms of applying three doses of lasers and comparing various laser wavelengths in the same study, which evaluates the effects of smoking on laser therapy and finds lasers effective in the treatment of peri-implantitis.

Ethics

Ethics Committee Approval: The study was performed in accordance with the principles of the Declaration of Helsinki and was approved by Kırıkkale University Clinical Research Ethics Committee (decision no: 09/02, date: 14.05.2019) and the Turkish Medicines and Medical Devices Agency (2019/060).

Informed Consent: Prior to the study, all individuals to be included in the study were given detailed information about the purpose and the method of the research and informed consent forms were obtained.

Peer-review: Externally peer-reviewed.

Authorship Contributions

Surgical and Medical Practices: K.B., Concept: K.B., E.O., Design: K.B., E.O., N.D.B., Data Collection or Processing: K.B., E.O., N.D.B., Analysis or Interpretation: K.B., E.O., N.D.B., Literature Search: K.B., E.O., Writing: K.B., E.O., N.D.B.

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: Kırıkkale University Scientific Research Projects number: 2019/023.