The effect of autologous leukocyte platelet rich fibrin on the rate of orthodontic tooth movement: A prospective randomized clinical trial

Efficacy of photobiomodulation following L-PRF application for recovery of mental nerve neurosensory disturbances caused by genioplasty: A randomized triple-blind clinical trial

The present study assessed the efficacy of photobiomodulation (PBM) following leukocyte-platelet rich fibrin (L-PRF) application for recovery of mental nerve neurosensory disturbances (NSDs) caused by genioplasty. This randomized triple-blind split-mouth clinical trial was conducted on 20 female patients (40 quadrants) requiring genioplasty. In each patient, one random side of the mandible served as the intervention (laser), and the other side as the control group. After genioplasty and L-PRF application, the intervention side underwent GaAIAs diode laser irradiation (880 nm, 500 mW, 15 J/cm2, 0.5 cm2 spot size, continuous-wave). Each point was laser irradiated for 15 s. Unilateral extraoral PBM was performed at 1, 3, 7, 14, 21, and 28 days, postoperatively. Laser in off mode (sham laser) was used for the control side. A visual analog scale (VAS) was used for general sensitivity, and 2-point discrimination, directional discrimination, pain discrimination, and thermal discrimination tests were used to assess the neurosensory recovery at 2 days, 2 weeks, 4 weeks, and 2 months, postoperatively. Statistical analyses were performed using two-way repeated measures ANOVA, Bonferroni test, and generalized estimating equation (alpha = 0.05). Time had a significant effect on improvement of all sensory variables (P < 0.05). Neurosensory recovery was significantly better in the intervention than the control group at all time points according to the two-point discrimination test (P = 0.0135) and brush test (P = 0.025) results. The interaction effect of time and intervention was not significant on any dependent variable (P > 0.05). Application of L-PRF + PBM resulted in significantly greater sensorineural recovery according to the two-point discrimination and brush test results.

Orthodontic tooth movement after periodontal regeneration of intrabony defects

The prevalence of intrabony defects in patients with advanced periodontitis stages III and IV is high. These patients usually need both periodontal treatment and orthodontic therapy, including tooth movement through bone defects, to improve masticatory function, aesthetics, and overall quality of life. Clinical practice guidelines recommend periodontal regenerative surgical interventions to resolve these defects and propose initiating orthodontic tooth movement (OTM) once periodontal therapy goals have been met. Surgical interventions using various regenerative technologies like barrier membranes and enamel matrix proteins, combined or not with bone replacement grafts, have proven effective in regenerating lost periodontal tissues. However, the combination of periodontal and orthodontic treatments requires consideration of how periodontal regenerative therapies influence OTM. Studies suggest that regenerated bone may differ in density, composition, vascularity, and cellular activity, potentially affecting the speed and efficiency of OTM, and potential root resorption of moved teeth. Understanding the sequence and timing of implementing OTM after regenerative periodontal interventions is crucial due to their interlinked processes of bone resorption and formation. This narrative review aims to uncover scientific evidence regarding these combined treatments, examining the impacts of different regenerative technologies on OTM and delineating their advantages, limitations, and best practices.

Effect of local administration of injectable platelet-rich fibrin on root resorption during orthodontic tooth movement in dogs

Background

This study aimed to assess the effect of local administration of injectable platelet-rich fibrin (i-PRF) on root resorption during orthodontic tooth movement in dogs.

Materials and Methods

This animal study was conducted on 4 adult male mongrel dogs. The right and left maxillary first premolars of the dogs were extracted, and a Nickel-Titanium closed coil spring was used to connect the canine to the second premolar with 150 g load. Next, 0.5 cc of i-PRF was injected in one quadrant of the maxilla around the second premolar into the periodontal ligament. The other quadrant of the maxilla served as the control group and received saline injection. Injections were performed at 1, 21, and 42 days, and the dogs were sacrificed after 63 days. Histological sections were prepared and cementum resorption, secondary cementum formation, and number of cementoblasts and cementoclasts were compared between the two groups by the Friedman test, Wilcoxon test, and Mann-Whitney test (α = 0.05).

Results

The mean percentage of cementum resorption (17.75% ± 5.56%) and secondary cementum formation (14.50% ± 6.65%), and the mean number of cementoblasts (10.25 ± 2.36) and cementoclasts (9.75 ± 4.71) were insignificantly higher in the i-PRF group than the corresponding values (13.75% ± 4.34%, 8.50% ± 2.88%, 7.75 ± 1.25, and 6.50 ± 3.10, respectively) in the control group (P > 0.05).

Conclusion

Administration of i-PRF insignificantly increased the percentage of cementum resorption, secondary cementum formation, number of cementoblasts, and number of cementoclasts.

Does the application of autologous injectable Platelet-Rich Fibrin (i-PRF) affect the patient's daily performance during the retraction of upper canines? A single-centre randomized split-mouth controlled trial

BACKGROUND

Previous studies have assessed different aspects concerning the applications of i-PRF in the oral cavity. However, nothing is known regarding patients' perceptions of the injection of autologous platelet-rich fibrin (i-PRF).

OBJECTIVES

To investigate patients' perceptions after injecting platelet-rich fibrin (i-PRF) in the course of retracting upper canines.

METHODS

Twenty-one patients, whose treatments required extractions of both upper first premolars, were recruited. Extraction side was randomly allocated to the intervention or control sides. After the alignment phase, i-PRF was injected twice with a one-month interval on the buccal and palatal aspects of the extraction sites (intervention side). Patients' perceptions were evaluated with two questionnaires: the first was used to assess the level of pain, discomfort, swelling, eating and swallowing difficulties as well as jaw movement restriction after 1 h (T1), 2 h (T2), 6 h (T3), 24 h (T4) and 48 h (T5) of the second injection; the second questionnaire was used to assess the acceptance of the i-PRF injection and overall satisfaction with this technique at the end of canine retraction phase. Visual Analogue Scale (VAS) was adopted for this purpose. Wilcoxon Signed Rank Test was used to compare between both sides at all time points while Friedman's Test was the selected test for detecting variables' changes over time. Post-hoc Wilcoxon Matched-Pairs Signed-Rank Tests were applied when any of the results were significant. As to the multiplicity of tests, Bonferroni Correction was implemented.

RESULTS

Pain and swelling levels were significantly higher on the experimental compared to the control sides at T1, T2, and T3 (P < 0.05), whereas they declined sharply and went back to almost normal values at T4 (after 24 h). At T5 they were 0. Discomfort and difficulty in mastication on intervention sides were significant only at T1 and T2. Pain, swelling, and chewing difficulties were significant (P < 0.001) during the 4 assessed time points. The increase was insignificant regarding swallowing difficulties and jaw movement limitations at all time intervals.

CONCLUSIONS

Injecting autologous (i-PRF) during orthodontic canine retraction is a well-perceived and well-tolerated method due to the limited discomfort which significantly diminishes 24 h afterwards.

TRIAL'S REGISTRATION

ClinicalTrials.gov (Identifier Number: NCT03399422. 16/01/2018).

Does leukocyte-platelet-rich fibrin (L-PRF) cause long term acceleration in the rate of canine retraction? A split-mouth, two-arm parallel group, randomized control trial

OBJECTIVE

The present study was conducted to investigate the effects of leukocyte-platelet-rich fibrin (L-PRF) on the rate of maxillary canine retraction for a period of 5 months.

METHODS

A split-mouth study was conducted on 16 subjects (9 males and 7 females; age range 17-25 years; mean age, 21.85±2.45 years) who required therapeutic extraction of bilateral maxillary first premolars. After the initial leveling and alignment, L-PRF plugs were placed in a randomly selected extraction socket (Experimental Group), and the other side served as a control (Control Group). Canine retraction was carried out by the activation of nickel-titanium (NiTi) closed-coil springs delivering 150 g of force. The rates of canine movement, canine rotation, tipping, root resorption, and molar movement were assessed at monthly intervals for five months (T0-T5). Pain, swelling and discomfort accompanying the procedure were assessed using a Likert scale.

RESULTS

The study revealed a significant increase in the rate of canine movement on the experimental side in the first two months, and significant molar anchorage loss was observed only in the first month for control side. There were no statistically significant differences between the groups regarding canine rotation, tipping, probing depth, root resorption, and pain perception.

CONCLUSIONS

The use of L-PRF plugs in extraction sockets considerably enhanced the rate of canine movement only in the first two months, and long-term efficacy was not observed in this study.

Does leucocyte- and platelet-rich fibrin enhance neurosensory recovery after genioplasty? A double-blind, split-mouth, randomised clinical trial

Neurosensory disturbances (NSD) are common after genioplasty. In this study we aimed to assess the recovery of NSDs with or without leukocyte- and platelet-rich fibrin (L-PRF) following genioplasty. In this double-blind, split-mouth, randomised clinical trial, L-PRF was applied around the mental nerve at the osteotomy site in genioplasty (treatment side). The contralateral side was considered the control side. Two-point discrimination (TPD) test, brush test, and self-reported NSDs (SR-NSD) were used to determine NSD at one, four, and 12 months after genioplasty. Twenty patients were studied. At one and four months after osteotomy, the mean scores of TPD and SR-NSDs were significantly different between the treatment and control sides (p = 0.04, p = 0.01, respectively). The mean of TPD and SR-NSDs was not statistically different on both sides 12 months after operation (p = 0.05, p = 0.71, respectively). The application of L-PRF may enhance the speed of NSD recovery four months after genioplasty.

Effect of leukocyte-platelet-rich fibrin (L-PRF) on the rate of orthodontic tooth movement and expression of various biomarkers in gingival crevicular fluid

OBJECTIVES

To assess the outcome of leukocyte-platelet-rich fibrin (L-PRF) on the rate of maxillary canine retraction and its correlation with the levels of Receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), and RANKL:OPG in the gingival crevicular fluid (GCF) during comprehensive orthodontic treatment.

SUBJECTS AND METHODS

Eighteen females who required all 1st premolars extraction for the correction of their class I bimaxillary protrusion malocclusions were included. The L-PRF plugs were placed in the experimental side 1st premolar extraction sockets. Canine retraction was performed by sliding mechanics. Canine retraction was assessed from the maxillary study models prepared just before the extraction (T₀) and then at 1 week (T₁), 2 weeks (T₂), 4 weeks (T₃), and 8 weeks (T₄) after the 1st premolar extraction and placement of L-PRF plugs. The concentrations of RANKL and OPG in the GCF were evaluated at T₀, T₁, T₂, T₃, and T₄.

RESULTS

In experimental sides, the amount of canine retraction was statistically more during the T₀-T₁, T₁-T₂, and T₂-T₃ periods. The mean concentration of RANKL at T₁, T₂, and T₃ was significantly more in the experimental sides. The mean concentration of OPG was significantly less in the experimental sides at T₂, T₃, and T₄. The RANKL:OPG was significantly more in the experimental sides at T₁, T₂, T₃, and T₄. No significant correlation was found between amount of canine retraction and concentration of RANKL and OPG and RANKL to OPG ratio in GCF.

CONCLUSIONS

The L-PRF accelerated the rate of maxillary canine retraction by 0.28 mm over an 8-week period. The L-PRF favored the local osteoclastogenesis by enhancing the RANKL and suppressing the OPG concentrations. There was no significant correlation between the rate of maxillary canine retraction and expression of RANKL, OPG, and RANKL:OPG in GCF.

TRIAL REGISTRATION

The Clinical Trials Registry of India (Reg. No. CTRI/2020/10/028390, Date-13.10.2020).

The effect of submucosal injection of platelet-rich fibrin vs. platelet-rich plasma on orthodontic tooth movement in rabbits; 28 days follow-up

OBJECTIVE

This study aimed to compare between the effects of submucosal injection of platelet rich fibrin (i-PRF) versus platelet rich plasma (PRP) on orthodontic tooth movement (OTM) in a rabbit model over a 28-day follow-up period.

MATERIALS AND METHODS

Sixty-three rabbits were assigned into 3 equal groups. Group I animals were subjected to the OTM without any treatments and considered as the control. Whereas groups II and III were handled as group I and instead i-PRF and PRP were injected submucosally in the buccal vestibular mucosa next to the mandibular 1st premolar, respectively. The distance of OTM was consecutively measured clinically after 7, 14 and 28 days. Seven rabbits from each group were euthanized after 7, 14 and 28 days for histological evaluation. Two-way ANOVA followed by LSD post-hoc statistical tests were used for comparison.

RESULTS

After 28 days, the mean tooth movements were 4.36±0.04mm in the control group, 6.30±0.06mm in the group receiving PRP and, 6.85±0.09mm in the group receiving i-PRF. Statistical analysis for the values of teeth movements revealed highly significant differences between different groups (P=0.001) and between different time periods (P=0.001). Histological analysis showed that submucosal injection of PRP and i-PRF yielded significant differences in periodontal ligament width in compression and tension sides between different groups (P=0.001) and between different time periods (P=0.001).

CONCLUSION

Submucosal injection of either PRP or i-PRF is a minimally invasive and safe approach for accelerating OTM. In this rabbit model, the effect of i-PRF is significantly more pronounced than the effect of PRP.

Effects of autologous leukocyte-platelet rich fibrin (L-PRF) on the rate of maxillary canine retraction and various biomarkers in gingival crevicular fluid (GCF): A split mouth randomized controlled trial

OBJECTIVES

Primary objective: To evaluate the effect of L-PRF on the rate of maxillary canine retraction.

SECONDARY OBJECTIVE

To validate the rate of maxillary canine retraction by identifying the levels of Interleukin-1β (IL-1β) and Tumour Necrosis Factor-α (TNF-α) in the Gingival Crevicular Fluid (GCF).

MATERIALS AND METHOD

Fifteen females (age range, 18-25 years) with Class I bimaxillary dentoalveolar protrusion malocclusions were included. After levelling and alignment of maxillary arches, 1st premolars were extracted from both sides. Canines were retracted immediately after the extraction of 1st premolars in control sides and placement of L-PRF plugs in the experimental sides. The amount of canine retraction was evaluated from study models recorded before the extraction of 1st premolars (T₀) and at 1-week (T₁), 2-weeks (T₂), 4-weeks (T₃), and 8-weeks (T₄) after the beginning of canine retraction by using digital model superimpositions. The concentrations of IL-1β and TNF-α were evaluated from the GCF collected at T₀, T₁, T₂, T₃, and T₄ by using commercially available human IL-1β and TNF-α ELISA kits.

RESULTS

The amount of canine retraction in the experimental sides was statistically greater during T₀-T₁ (P=0.038),T₁-T₂ (P=0.002), and T₂-T₃ (P=0.011) periods. Total canine retraction during T₀-T₄ was statistically greater in experimental sides (2.43±0.46mm) than control sides (2.08±0.28mm) (P=0.001). The concentration of IL-1β increased significantly in the experimental sides at T₁ (P=0.000),T₂ (P=0.000), and T₃ (P=0.032). The concentration of TNF-α increased both in the control and experimental sides, but it was statistically greater in the experimental sides compared to control sides at T₁ (P=0.000) and T₂ (P=0.006). A positive but not statistically significant correlation was noted between the rate of canine retraction and the concentrations of cytokines such as IL-1β and TNF-α in GCF.

CONCLUSION

Over an 8-week period, autologous L-PRF statistically accelerated the rate of maxillary canine retraction, but only by 0.35mm. This small acceleration occurred mainly in the first 4 weeks. During the following 4 weeks, the amount of canine retraction was comparable on the experimental and control sides.

Evaluation of injectable platelet-rich fibrin effect on the rate of canine retraction and alkaline phosphatase levels: An in-vivo study

INTRODUCTION

With time, the treatment protocol has changed, and currently, there is a new school of treatment called accelerated orthodontics, wherein the goal is to shorten the time. In this study, a liquid formulation of platelet-rich fibrin such as injectable platelet-rich fibrin (i-PRF), was used, and its effect on the rate of canine retraction and the crevicular alkaline phosphatase (ALP) levels were studied.

METHODS

Thirteen patients were recruited for this study with a mean age of 20.6 ± 3.2 years. A split-mouth type of study design was used in which the maxillary arch of each subject was divided into an experimental and control group. I-PRF was injected in the labial and lingual attached gingiva of the canine in the experimental group. The gingival crevicular fluid collection was done from the distal aspect of the canine before canine retraction, 24 hours after retraction, and 28 days after retraction from both sites (ie, control and experimental sites). ALP activity was analyzed using a semiautomated analyzer, and the rate of canine retraction was measured on stone casts with the help of a digital vernier caliper.

RESULTS

The individual canine retraction was 1.8-fold faster in the i-PRF group than in the control group. The ALP activity was significantly greater at 24 hrs and 28 days after retraction in the experimental group.

CONCLUSIONS

These results suggest that i-PRF is an innovative, noninvasive approach to accelerating tooth movement. ALP activity in gingival crevicular fluid reflects the biological changes in the periodontium, and the steep increase in the activity indicates increased bone remodeling within the experimental group.

Effectiveness of platelet-rich concentrates on the rate of orthodontic tooth movement: a systematic review and meta-analysis

BACKGROUND

Autologous platelet-rich concentrates (PRCs) are recently used as a local biological substance in orthodontics to accelerate the rate of tooth movement.

OBJECTIVES

This systematic review aimed to evaluate the effects of PRCs on the rate of orthodontic tooth movement (OTM).

SEARCH METHODS

Unrestricted search of five electronic databases supplemented by the manual and gray literature search were undertaken in March 2022.

SELECTION CRITERIA

Randomized controlled trials (RCTs) evaluating the effect of PRCs on the rate of OTM with their side effect were included in this systematic review.

DATA COLLECTION AND ANALYSIS

Data items were extracted by two authors using a pre-piloted extraction form. Similar outcomes within a comparable time frame were synthesized in a meta-analysis.

RESULTS

Fourteen studies were deemed eligible for inclusion and seven RCTs were pooled in a meta-analysis. Canine retraction rate was higher in the side of PRCs injection than the control side by 0.28 mm/month (95% CI: 0.16-0.40, I2 = 95.6 per cent, P < 0.001, 345 patients) in the first 4 months after PRCs injection. There was no statistically significant difference between the PRCs side and the control side regarding molar anchorage loss (MAL) (MD = 0.03 mm, 95% CI: -0.18 to 0.24, I2 = 46.3 per cent, P = 0.78, 44 patients), canine rotation (MD = -0.19o, 95% CI: -1.95 to 1.57, I2 = 45.4 per cent, P = 0.96, 48 patients), or en-masse retraction. Likewise, there was no difference between both groups in terms of the duration of de-crowding. The mandibular canine retraction was statistically higher on the PRCs side than on the control side by 0.17 mm/month (P < 0.001, one trial). Regarding root resorption, there was no statistically significant difference between the experimental and control sides within the follow-up time. Mild pain scores were reported by the patients in the first 24 hours after injections.

CONCLUSIONS

Low-level evidence indicates that the effect of PRCs on OTM is minor and clinically insignificant. The findings should be interpreted with caution due to the inherent limitations in the included RCTs.

REGISTRATION

PROSPERO (CRD42022300026).

The effect of platelet-rich concentrates on orthodontic tooth movement: A review of randomized controlled trials

Objectives

Platelet-rich concentrates, namely platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), have recently shown potential roles in accelerating orthodontic tooth movement (OTM) and reducing treatment duration. Our study aims to systematically evaluate the effect of platelet-rich concentrates on OTM.

Materials and methods

An electronic search of 11 databases, followed by a hand search of reference lists of eligible studies and related reviews, was conducted up to January 2022. Randomized controlled trials investigating OTM of patients with platelet-rich concentrates were included. Risk of bias was assessed by version 2 of Cochrane tool (RoB 2) for assessing risk of bias in randomized trials.

Results

Among 715 records initially identified, 9 studies were included, of which 3 used PRP and the other 6 applied PRF. 7 studies supported a positive relationship between platelet-rich concentrates and OTM, but the other 2 studies reported a null and a negative effect of PRF, respectively. The overall qualities of evidence were moderate to high.

Conclusions

Platelet-rich concentrates as PRP and PRF seem to be effective in accelerating OTM at early stages, while their long-term efficacy remains controversial. Repeated application of platelet concentrates may increase the accelerated stability of OTM.

Do platelet concentrates accelerate orthodontic tooth movement?: a systematic review

PURPOSE

Surgical techniques in orthodontics have received widespread attention in recent years. Meanwhile, biomaterials with high molecular content have been introduced, such as platelet concentrates (PCs), which may accelerate orthodontic tooth movement (OTM) and reduce periodontal damage. The present systematic review aimed to answer the following PICO question: "In patients in whom orthodontic surgical techniques are performed (P), what is the effectiveness of using PCs over the surgical site (I) when compared to not placing PCs (C) to achieve faster tooth movement (O)?"

METHODS

A search was performed in 6 databases. The criteria employed were those described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses declaration. The present review included studies with a control group that provided information about the influence of PCs on the rate of OTM.

RESULTS

The electronic search identified 10 studies that met the established criteria.

CONCLUSIONS

The included studies were very diverse, making it difficult to draw convincing conclusions. However, a tendency was observed for OTM to be accelerated when PCs were used as an adjuvant for canine distalization after premolar extraction when distalization was started in the same session. Likewise, studies seem to indicate an association between PC injection and the amount of canine retraction. However, it is not possible to affirm that the use of PCs in corticotomy shortens the overall treatment time, as this question has not been studied adequately.

TRIAL REGISTRATION

PROSPERO Identifier: CRD42021278542.

Impact of Frontier Development of Alveolar Bone Grafting on Orthodontic Tooth Movement

Sufficient alveolar bone is a safeguard for achieving desired outcomes in orthodontic treatment. Moving a tooth into an alveolar bony defect may result in a periodontal defect or worse–tooth loss. Therefore, when facing a pathologic situation such as periodontal bone loss, alveolar clefts, long-term tooth loss, trauma, and thin phenotype, bone grafting is often necessary to augment bone for orthodontic treatment purposes. Currently, diverse bone grafts are used in clinical practice, but no single grafting material shows absolutely superior results over the others. All available materials demonstrate pros and cons, most notably donor morbidity and adverse effects on orthodontic treatment. Here, we review newly developed graft materials that are still in the pre-clinical stage, as well as new combinations of existing materials, by highlighting their effects on alveolar bone regeneration and orthodontic tooth movement. In addition, novel manufacturing techniques, such as bioprinting, will be discussed. This mini-review article will provide state-of-the-art information to assist clinicians in selecting grafting material(s) that enhance alveolar bone augmentation while avoiding unfavorable side effects during orthodontic treatment.

Platelet-rich derivatives for accelerating the rate of orthodontic tooth movement - a systematic review and meta-analysis

Objective:

The aim of this systematic review and meta-analysis was to report on the effects of using platelet-rich derivatives on the rate of tooth movement.

Material and Methods:

Both electronic and manual searches were performed with specific eligibility criteria based on population, intervention, comparison, outcome, and study design. Risk of bias (RoB) assessment was done using the Cochrane RoB tool 2, the data were pooled and analyzed using review manager 4.5, and certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. Two independent reviewers performed the study selection, data extraction, and analysis. Nine studies were included for qualitative analysis and two of them were subjected to meta-analysis.

Results:

The standard mean difference for the rate of canine distal movement with platelet-rich derivatives was not significantly higher than controls at any of the time intervals (P > 0.0001). Rotation of canines, molar mesialization, and pain scores were not affected by the administration of platelet-rich derivatives for accelerating tooth movement. A moderate to high RoB was noted in the included studies and the certainty of the available evidence as assessed by the GRADE approach was moderate.

Conclusion:

The included studies presented with high heterogeneity and more high-quality studies with strict protocols are needed. Even though individual studies report significant acceleration of tooth movement following administration of PR derivatives, moderate certainty of evidence suggests no acceleratory effect on tooth movement.

The adjunctive effect of autologous platelet concentrates on orthodontic tooth movement: A systematic review and meta-analysis of current randomized controlled trials

OBJECTIVE

To evaluate the effectiveness of autologous platelet concentrates (APCs) as adjuncts on accelerating orthodontic tooth movement (OTM) of the human subjects undergoing orthodontic treatment and to critically appraise the available literature.

METHODS AND MATERIALS

Five electronic databases (PubMed, Scopus, Web of Science, Embase, and Cochrane Central Register of Controlled Trials) were searched from 2000 up to May 2021 to retrieve eligible randomized controlled trials (RCTs) investigating patients who underwent orthodontic treatment that involved OTM of maxillary and mandibular incisors and canines. All the enrolled cases were treated with APCs and had no local or systemic interfering factors. The quality of the included studies was assessed using the modified JADAD scale. The effect sizes were assessed using mean difference (MD). The heterogeneity analysis was conducted using (I²) statistic at α=0.10.

RESULTS

Finally, seven RCTs were included in the qualitative, and two RCTs were included in the quantitative analysis. The meta-analysis was performed regarding the effect of injectable platelet-rich fibrin (I-PRF) on the rate of canine tooth movement in millimeters at different intervals of the 1^st, 2^nd, and 3^rd months. In the 1^st month, I-PRF (WMD:0.12mm, CI95% -5.01 to 5.24, I²=90%) did not significantly affect OTM. In the 2^nd month, I-PRF (WMD:0.66mm, CI95% 0.60 to 0.73, I²=10%) significantly increased the OTM. However, in the 3^rd month, I-PRF did not significantly increase the OTM (WMD:0.54mm, CI95% -1.38 to 2.47, I²=67%).

CONCLUSIONS

According to the low certainty of evidence about this topic, providing a definite conclusion is not possible. However, applying I-PRF seems to be efficient in accelerating the OTM of the canines. Further high-quality studies with larger sample sizes will be indispensable to validate this conclusion.

Effectiveness of platelet rich fibrin versus demineralized bone xenograft in periodontally accelerated osteogenic orthodontics: A pilot comparative clinical study

OBJECTIVES

To compare the rate of extraction space closure between periodontally accelerated osteogenic orthodontics (PAOO) using platelet-rich fibrin (PRF) (Group 1) and PAOO using demineralized bone xenograft (DMBM) (Group 2) and to compare the level of wound healing between the PRF group vs the DMBM group after PAOO.

MATERIALS AND METHODS

A two-arm prospective single blind pilot study with a split-mouth design was used in which 14 patients requiring premolar extraction were divided into two groups: PRF and DMBM. En-masse space closure was carried out with using mini implants after the PAOO procedure. The amount of space closure was measured at five time points with 2-week intervals within 2 months. The gingival healing levels were assessed using early wound healing scores on the first postoperative day.

RESULTS

The rate of extraction space closure was faster in the experimental quadrant at all time points (T1-T4) in the PRF group and at time points (T3, T4) in the DMBM group. Comparison between experimental quadrants showed a significant increase in the rate of space closure in the PRF group T1 to T3 (P < .05). The PRF group showed higher total early healing scores than the DMBM group.

CONCLUSIONS

PRF, when used in the PAOO procedure, produces a faster rate of space closure with better early wound healing than DMBM.

Local hormones and growth factors to enhance orthodontic tooth movement: A systematic review of animal studies

BACKGROUND

Prolonged treatment times are the main reason capable of affecting patient compliance with orthodontic treatment.

OBJECTIVES

A systematic review was made to determine whether the local administration of hormones and growth factors effectively enhances orthodontic tooth movement, and to identify possible adverse effects in animal studies.

MATERIALS AND METHODS

Five databases (PubMed, Scopus, EMBASE, Web of Science and Cochrane Library) were checked for experimental studies reporting one of the following outcomes: orthodontic tooth movement, histological outcomes and side effects. After data extraction, orthodontic tooth movement linked to adjunctive substances was analysed using forest plots. The risk of bias and the quality of evidence were determined with the SYRCLE tool and the GRADE tool, respectively.

RESULTS

Twenty-four studies were included in the systematic review. On a specific dose level, epidermal growth factor + liposomes, fibroblast growth factor and prostaglandin E₂  + Ca were supported by a moderate level of evidence and rated as highly effective in increasing tooth movement in animal models. Likewise, there was histological evidence of increased bone remodelling after the administration of these substances. Other compounds were supported by a low to very low level of evidence.

CONCLUSIONS

Hormones and growth factors may have a relevant impact upon orthodontic tooth movement rate. In specific formulations, prostaglandin E₂ , fibroblast growth factor and epidermal growth factor showed promising results.

Immune Changes Induced by Orthodontic Forces: A Critical Review

Orthodontic tooth movement (OTM) is generated by a mechanical force that induces an aseptic inflammatory response in the periodontal tissues and a subsequent coordinated process of bone resorption and apposition. In this review, we critically summarize the current knowledge on the immune processes involved in OTM inflammation and provide a novel insight into the relationship between classical inflammation and clinical OTM phases. We found that most studies focused on the acute inflammatory process, which ignites the initial alveolar bone resorption. However, the exact mechanisms and the immune reactions involved in the following OTM phases remain obscure. Recent studies highlight the existence of a typical innate response of resident and extravasated immune cells, including granulocytes and natural killer (NK), dendritic, and γδT cells. Based on few available studies, we shed light on an active, albeit incomplete, process of resolution in the lag phase, supported by continuously elevated ratios of M1/M2 macrophage and receptor activator of nuclear factor κB ligand/osteoprotegerin ratio. This partial resolution enables tissue formation and creates the appropriate environment for a transition between the innate and adaptive arms of the immune system, essential for the tissue's return to homeostasis. Nevertheless, as the mechanical trigger persists, the resolution turns into a low-grade chronic inflammation, which underlies the next, acceleration/linear OTM phase. In this stage, the acute inflammation dampens, and a simultaneous process of bone resorption and formation occurs, driven by B and T cells of the adaptive immune arm. Excessive orthodontic forces or tooth movement in periodontally affected inflamed tissues may hamper resolution, leading to "maladaptive homeostasis" and tissue loss due to uncoupled bone resorption and formation. The review ends with a brief description of the translational studies on OTM immunomodulation. Future studies are necessary for further uncovering cellular and molecular immune targets and developing novel strategies for controlling OTM by local and sustained tuning of the inflammatory process.

Effect of injectable platelet-rich fibrin (i-PRF) on the rate of tooth movement

OBJECTIVES

To evaluate the efficiency of injectable platelet-rich fibrin (i-PRF) in accelerating canine tooth movement and to examine levels of the matrix metalloproteinase-8 (MMP-8), interleukin-1β (IL-1β), receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cells ligand (RANKL), and osteoprotegerin (OPG) in the gingival crevicular fluid during orthodontic treatment.

MATERIALS AND METHODS

Twenty patients (mean age = 21.4 ± 2.9 years) with Class II Division 1 malocclusion were included in a split-mouth study. The treatment plan for all patients was extraction of maxillary first premolars followed by canine distalization with closed-coil springs using 150 g of force on each side. The study group received i-PRF two times, with a 2-week interval, on one side of the maxilla. The contralateral side served as the control and did not receive i-PRF. Maxillary canine tooth movement was measured at five time points (T1-T5) on each side. Also, the activity of inflammatory cytokines was evaluated at three time points in the gingival crevicular fluid samples.

RESULTS

There was a significant difference in canine tooth movement between the two groups (P < .001). i-PRF significantly increased the rate of tooth movement, and stimulation in the levels of inflammatory cytokines supported this result (P < .001). The levels of cytokines changed in both groups between T1 and T2. The IL-1β, MMP8, and RANKL values were significantly increased in the study group compared with the control group, while the OPG values were significantly decreased.

CONCLUSIONS

i-PRF-facilitated orthodontics is an effective and safe treatment modality to accelerate tooth movement, and this method can help shorten orthodontic treatment duration.

Assessment of the effects of local platelet-rich fibrin injection and piezocision on orthodontic tooth movement during canine distalization

INTRODUCTION

The study aimed to evaluate and compare the effects of local platelet-rich fibrin (PRF) injection and piezocision applications on tooth movement during canine distalization, as well as to evaluate any changes in the periodontal parameters.

METHODS

Twenty-four patients were randomly divided into 2 groups. A randomly selected side of the maxillary arch received either PRF injection (PRF group) or piezocision (piezocision group). The contralateral sides of both groups served as the controls. After piezocision and PRF injection applications, canine distalization was initiated in both groups with a 150 g force. Patients were followed every 2 weeks for a total 12 of weeks. The following variables were evaluated: cephalometric measurements, the amount of canine distalization, molar mesialization, canine rotation, transversal changes in dental models, and periodontal parameters.

RESULTS

The amount of canine distal movement was found to be greater in the experimental sides than in the control sides in both groups at 12 weeks (P <0.05). There were no differences in the amount of molar mesialization, canine rotation, or transversal measurements in both groups when compared with the experimental sides with the control sides (P >0.05). There were no differences in the skeletal measurements or periodontal parameters in both groups (P >0.05). In both groups, the maxillary incisors were retroclined and retracted.

CONCLUSIONS

PRF and piezocision accelerated tooth movement, but there were no differences between the 2 applications in terms of speed, amount, duration of tooth movement, or periodontal parameters during canine distalization.

The impact of platelet-rich fibrin (PRF) on delayed tooth replantation: A preliminary animal study

The aim of this study was to evaluate the effect of platelet-rich fibrin (PRF) placed in delayed replantation of mature extracted teeth. Sixteen intentionally extracted teeth in two mature beagle dogs were selected. In one quadrant of each jaw, the extraction sockets were filled with PRF prior to replantation, and the other quadrant served as control without PRF. All extracted teeth underwent endodontic treatment and dried for 60 min. Thereafter, they were replanted with a flexible splint. After 8 weeks, the animals were euthanised, and the histological sections examined. Less inflammatory root resorption was noted in the PRF group compared to the control (P = 0.031). However, there was no significant difference between the two groups with regard to new bone formation, inflammatory status, connective tissue healing and replacement resorption (P > 0.05). Using PRF in the extracted socket before delayed replantation did not provide any significant benefit other than reduced inflammatory root resorption.

Three-dimensional evaluation of the effects of injectable platelet rich fibrin (i-PRF) on alveolar bone and root length during orthodontic treatment: a randomized split mouth trial

Background

The role of injectable platelet rich fibrin (i-PRF) in orthodontic treatment has not been investigated with focus on its effect on dental and bony periodontal elements.

Objective

To evaluate the efficacy of i-PRF in bone preservation and prevention of root resorption.

Methods

A randomized split-mouth controlled trial included 21 patients aged 16–28 years (20.85 ± 3.85), who were treated for Class II malocclusion with the extraction of the maxillary first premolars. Right and left sides were randomly allocated to either experimental treated with i-PRF or control sides. After the leveling and alignment phase, the canines were retracted with 150gm forces. The i-PRF was prepared from the blood of each patient following a precise protocol, then injected immediately before canine retraction on the buccal and palatal aspects of the extraction sites. Localized maxillary cone beam computed tomography scans were taken before and after canine retraction to measure alveolar bone height and thickness and canine root length (indicative of root resorption), and the presence of dehiscence and fenestration. Paired sample t-tests and Wilcoxon signed rank tests were used to compare the changes between groups.

Results

No statistically significant differences in bone height, bone thickness were found between sides and between pre- and post-retraction period. However, root length was reduced post retraction but did not differ between sides. In both groups, postoperative dehiscence was observed buccally and palatally and fenestrations were recorded on only the buccal aspect.

Conclusions

I-PRF did not affect bone quality during canine retraction or prevent canine root resorption. I-PRF did not reduce the prevalence of dehiscence and fenestration.

Trial registration ClinicalTrials.gov (identifier number: NCT 03399760. 16/01/2018).

The effect of platelet-rich fibrin (PRF) on maxillary incisor retraction rate

OBJECTIVE

To investigate the efficiency of platelet-rich fibrin (PRF) injection on maxillary incisor retraction rate.

MATERIALS AND METHODS

The study included 40 patients (23 women and 17 men; mean age; 20.7 ± 1.45) with Class II Division 1 malocclusion. The treatment plan for all patients was extraction of the maxillary first premolars and canine distalization, followed by retraction of the maxillary incisors. Patients were randomly divided into two groups. The study group received injectable platelet-rich fibrin (i-PRF) two times with an interval of 2 weeks; the control group did not receive i-PRF. In both groups, the measurements were bilaterally assessed as the distances between the lateral and canine teeth on the plaster models at five time points. The rate of incisor movement was evaluated by Student's t-test, analysis of variance, and Tukey honestly significant difference tests. Statistical significance was set as P < .05.

RESULTS

The average movements of incisors were significantly higher in the study group than the control group at all time points (P < .05). According to the within-group comparison, none of the measurements showed any significant differences between the right and left sides in both groups at all time points (P > .05). While the movement of incisors was significantly higher in the study group in the week following the PRF injection compared to the other weeks (P < .05), there were no significant differences in the control group at all-time points (P > .05).

CONCLUSIONS

Applying i-PRF significantly increased the rate of maxillary incisor retraction at all time intervals. Platelet-rich fibrin injection can be an effective method for shortening treatment duration.

The effect of the local administration of biological substances on the rate of orthodontic tooth movement: a systematic review of human studies

BACKGROUND

The influence of different biological agents on the rate of orthodontic tooth movement (OTM) has been extensively reviewed in animal studies with conflicting results. These findings cannot be extrapolated from animals to humans. Therefore, we aimed to systematically investigate the most up-to-date available evidence of human studies regarding the effect of the administration of different biological substances on the rate of orthodontic tooth movement.

METHODS

A total of 8 databases were searched until the 16th of June 2020 without restrictions. Controlled randomized and non-randomized human clinical studies assessing the effect of biological substances on the rate of OTM were included. ROBINS-I and the Cochrane Risk of Bias tools were used. Reporting of this review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 11 studies (6 randomized clinical trials and 5 prospective clinical trials) were identified for inclusion. Local injections of prostaglandin E1 and vitamin C exerted a positive influence on the rate of OTM; vitamin D showed variable effects. The use of platelet-rich plasma and its derivatives showed inconsistent results, while the local use of human relaxin hormone showed no significant effects on the rate of OTM.

LIMITATIONS

The limited and variable observation periods after the administration of the biological substances, the high and medium risk of bias assessment for some included studies, the variable concentrations of the assessed biological agents, the different experimental designs and teeth evaluated, and the variety of measurement tools have hampered the quantitative assessment of the results as originally planned.

CONCLUSIONS AND IMPLICATIONS

Despite the methodological limitations of the included studies, this systematic review provides an important overview of the effects of a variety of biological agents on the rate of tooth movement and elucidates the deficiencies in the clinical studies that have been conducted so far to evaluate the effectiveness of these agents in humans, providing some guidelines for future robust research.

TRIAL REGISTRATION

PROSPERO ( CRD42020168481 , www.crd.york.ac.uk/prospero ).

Effect of injectable platelet-rich fibrin (i-PRF) in accelerating orthodontic tooth movement : A randomized split-mouth-controlled trial

BACKGROUND

The role of platelet-rich fibrin (PRF) in accelerating orthodontic tooth movement has been controversially discussed in available clinical studies.

OBJECTIVE

To investigate the effectiveness of i‑PRF in accelerating maxillary canine retraction.

MATERIALS AND METHODS

A split-mouth design was applied in 21 participants (6 men, 15 women; mean age: 20.85 ± 3.85 years) whose class II division I malocclusion required the extraction of both maxillary first premolars. The right and left canines were randomized into intervention and control sides. After the initial leveling and alignment phase and immediately before canine retraction, i‑PRF obtained from the brachial vein was injected into the mucosa on the buccal and palatal aspects of the intervention sides. The injection was repeated one month later. Study casts were taken at the initiation of canine retraction (T0) and at monthly visits up to 5 months (T1 through T5). The paired t‑test was used to compare the total and monthly rates of canine retraction, canine rotation, and anchorage loss.

RESULTS

The average rates of canine retraction were greater on the experimental side at T2, T3, and T4, but this difference with the control side was statistically significantly different only at T2 (P < 0.05). Differences in canine rotation and anchorage loss were not statistically significant.

CONCLUSION

The rates of canine retraction following the injection of platelet-rich fibrin were not statistically significantly greater on the experimental than the control sides except at the second month (T2). This apparently transient rate of tooth movement indicates that repeated injections might be needed for sustained effects, a premise meriting more focused research.

Effect of Carbonate Apatite Hydrogel-Advanced Platelet-Rich Fibrin Injection on Osteoblastogenesis during Orthodontic Relapse in Rabbits

Objective  This study aimed to determine the effect of carbonate apatite (CHA) hydrogel-aPRF on osteoblastogenesis during relapse in rabbits.

Materials and Methods  Forty-five rabbits were divided into three groups ( n = 15): the control, CHA, and CHA-autologous platelet-rich fibrin (aPRF) groups. An open-coil spring was compressed between brackets to distalize the lower incisors of the rabbits by delivering a force of 50 cN for 1 week. The new position of the teeth was retained for 14 days, and CHA hydrogel-aPRF was injected every 7 days. The appliances were then debonded to allow relapse. On days 0, 3, 7, 14, and 21 after debonding, transforming growth factor (TGF)-β1 and bone morphogenetic protein (BMP)-2 expression was examined using immunohistochemistry staining and Runx-2 levels were analyzed by enzyme-linked immunosorbent assay. The data collected were analyzed using analysis of variance and a post hoc Tukey’s test ( p < 0.05).

Results  Histomorphometric analysis revealed that TGF-β1 expression in the CHA-aPRF group is statistically higher than that in other groups on days 0, 3, and 7 after debonding ( p < 0.05). BMP-2 expression in the CHA-aPRF group was also statistically higher than that in the other groups on days 3, 14, and 21 after debonding ( p < 0.05). ELISA showed that Runx-2 levels are slightly higher in the CHA-aPRF group than in the other groups ( p > 0.05).

Conclusion  Although injection of CHA-aPRF aids in osteoblastogenesis associated with enhancing TGF-β1 and BMP-2 expressions, it does not significantly upregulate Runx-2 levels.

Evidence-Based Clinical Efficacy of Leukocyte and Platelet-Rich Fibrin in Maxillary Sinus Floor Lift, Graft and Surgical Augmentation Procedures

Bone augmentation techniques have increasingly been indicated for re-creating adequate bone height and volume suitable for dental implant sites. This is particularly applicable in the severely atrophic posterior maxilla where sinus perforation (ruptured Schneiderian membrane) is a very common complication and sinus floor elevation or lift is frequently considered a standard procedure. The augmentation of the maxillary sinus can be performed with or without grafting biomaterials. Herein, numerous biomaterials and bone substitutes have been proposed, primarily to sustain the lifted space. In addition, cytokines and growth factors have been used to stimulate angiogenesis, enhance bone formation as well as improve healing and recovery period, either as the sole filling material or in combination with bone substitute materials. Within such, is the family of autologous blood extracts, so-called platelet concentrates, which are simply the "product" resulting from the simple centrifugation of collected whole blood samples of the patient, immediately pre-surgery. Platelet-Rich Fibrin (PRF), a sub-family of platelet concentrates, is a three-dimensional (3-D) autogenous biomaterial obtained, without including anti-coagulants, bovine thrombin, additives, or any gelifying agents during the centrifugation process. Today, it is safe to say that, in implant dentistry and oral and maxillofacial surgery, PRFs (particularly, the pure platelet-rich fibrin or P-PRF and leukocyte and platelet-rich fibrin or L-PRF sub-classes) are receiving the most attention, essentially due to their simplicity, rapidness, user-friendliness/malleability, and cost-effectiveness. Whether used as the sole "bioactive" filling/additive material or combined with bone substitutes, the revolutionary second-generation PRFs have been very often associated with promising clinical results. Hence, this review aims to provide a 10-years update on the clinical effectiveness of L-PRF when applied/used as the "sole" biomaterial in maxillary sinus augmentation procedures. An electronic search using specific keywords for L-PRF and maxillary sinus augmentation was conducted in three main databases (PubMed-MEDLINE database, Google Scholar and Cochrane library) for the period between January 2009-February 2020. The quest yielded a total of 468 articles. Based on the pre-established strict inclusion/exclusion criteria, only seven articles were deemed eligible and included in the analysis. Surprisingly, of the 5 studies which used de-proteinized bovine bone mineral (DBBM) in combination with L-PRF, 60% acclaimed no significant effects and only 40% declared positive effects. Of the two articles which had used allogenous bone graft, 50% declared no significant effects and 50% acclaimed positive effects. Only one study had used L-PRF as the sole grafting material and reported a positive effect. Likewise, positive effects were reported in one other study using L-PRF in combination with a collagen membrane. Due to the heterogeneity of the included studies, this review is limited by the inability to perform a proper systematic meta-analysis. Overall, most of the published studies reported impressive results of L-PRF application as a grafting material (sole or adjuvant) in maxillary sinus augmentation and dental implant restorative procedures. Yet, distinct technical processing for L-PRF preparation was noted. Hence, studies should be approached with caution. Here in, in sinus lift and treatment of Schneider membrane, the formation of mature bone remains inconclusive. More studies are eagerly awaited in order to prove the beneficial or detrimental effects of PRFs, in general and L-PRFs, in specific; especially in their tissue regenerative potential pertaining to the promotion of angiogenesis, enhancing of cell proliferation, stimulation of cell migration and autocrine/paracrine secretion of growth factors, as well as to reach a consensus or a conclusive and distinct determination of the effect of leukocytes (and their inclusion) on inflammation or edema and pain; a call for standardization in PRFs and L-PRFs composition reporting and regimenting the preparation protocols.

Distalization rate of maxillary canines in an alveolus filled with leukocyte-platelet-rich fibrin in adults: A randomized controlled clinical split-mouth trial

INTRODUCTION

The objective of this study was to evaluate the distalization rate and changes in inclination of the maxillary canines in alveoli preserved with leukocyte-platelet-rich fibrin (L-PRF) membranes in adult patients. The null hypothesis was that there are no differences in the canine distalization movement rate between the treated and the control sides.

METHODS

A total of 21 healthy adult patients with a minimum age of 20 years (mean age, 33 ± 5.9 years) and Angle Class I or Class II Division 1 malocclusion, who had an indication of extraction of the maxillary first premolars and orthodontic distalization of the maxillary canines were included in this study. A randomized controlled clinical split-mouth trial was conducted; the experimental maxillary side was treated with L-PRF membranes, and the other side served as the control. A randomization sequence of the experimental sides among patients was generated using the random number generation function of Microsoft Excel. Neither the patients nor the operators were blinded. Fifteen days after the extractions, distalization was initiated using an elastic chain applying 150 g of force to the canines on a 0.020-in stainless steel archwire. The distalization rate was the main outcome of the study, and it was assessed monthly for 5 months through the intraoral use of a flexible ruler. The degree of inclination of the canines was the secondary outcome, and it was evaluated through cone-beam computed tomography. A Shapiro-Wilk test was performed, and a Wilcoxon signed rank test was subsequently used to compare the experimental and the control group. Spearman rank correlation coefficient was calculated to evaluate the correlation between distalization and inclination for each side.

RESULTS

Four of the subjects dropped out of the study, leaving a total of 17 patients (n = 17). The distalization rate and inclination of the canines were greater on the control side than on the side treated with L-PRF (P <0.05). A weak correlation was found between the distalization rate and inclination of the canines for both sides (control side, ρ = 0.17; experimental, ρ = 0.11). No harm was observed during the study.

CONCLUSIONS

The null hypothesis was rejected. The use of L-PRF in young adult patients decreased the rate of distalization and changes in inclination of the maxillary canines compared with the control group.

REGISTRATION

This trial was not registered.

PROTOCOL

The protocol was not published before trial commencement.

Platelet-Rich Fibrin in Bone Regenerative Strategies in Orthodontics: A Systematic Review

Preservation of the alveolar bone is a determinant in the outcome of orthodontic treatment. Alveolar bone defects or a decrease of their height and width may occur due to common reasons such as inflammation, tooth extraction, or cleft lip and palate. The aim of this systematic review was to investigate and appraise the quality of the most up to date available evidence regarding the applications and effects of platelet-rich fibrin (PRF) in orthodontics. This study was carried out according to preferred reporting items for systematic reviews and meta-analyses guidelines using the following databases: Medline via PubMed, Cochrane Library, Web of Science Core Collection and EMBASE. The qualitative assessment of the included studies was performed using Cochrane Risk of Bias tool and ROBINS-I guidelines. Results: From a total of 489 studies, nine studies were selected. The majority of the included studies demonstrate that autogenous anterior iliac graft with PRF had a higher amount of newly formed bone. Furthermore, this review also suggests that the application of platelet derivatives in the extraction socket can accelerate orthodontic tooth movement. Despite the limitations in the included studies, this systematic review suggested that PRF can improve alveolar cleft reconstruction and orthodontic tooth movement.

Effects of Leukocyte-Platelet-Rich Plasma on the Alveolar Bone Changes During Orthodontic Tooth Movement in Rabbits: A Micro-CT Study

Objective: To investigate the effects of leukocyte-platelet-rich plasma (L-PRP) on the alveolar bone changes at the compression and tension sides during orthodontic tooth movement.

Materials and Methods: Around 20 New Zealand white rabbits were used in a split-mouth design. The maxillary first premolar was moved mesially with a nickel-titanium closed-coil spring. One side of the maxilla was randomly injected with L-PRP, while the contralateral side served as the control which received normal saline. The alveolar bone adjacent to the maxillary first premolar was scanned using microcomputed tomography at days 0, 7, 14, and 28. Microstructural parameters including bone volume fraction, trabecular thickness, and trabecular separation of alveolar bone were assessed on the compression and tension sides of the maxillary first premolar.

Results: Compared between the groups, the L-PPR group showed a significantly decreased bone volume fraction on the compression side on days 7 and 14 but significantly increased bone volume fraction on the tension side on day 14. However, there were no statistically significant differences in the parameters of trabecular thickness and trabecular separation.

Conclusion: Local administration of L-PRP may promote bone resorption on the compression side and bone formation on the tension side at the initial stage of orthodontic tooth movement.

Histomorphometric and Histopathologic Evaluation of the Effects of Systemic Fluoride Intake on Orthodontic Tooth Movement

Objectives  The aim of this study was to determine the effects of systemic fluoride intake on orthodontic tooth movement with histomorphometric and histopathologic methods.

Materials and Methods  Forty-eight Wistar albino rats were randomly divided into four groups of 12 rats each. Group I received fluoridated water and underwent orthodontic tooth movement. Group II received fluoridated water and did not undergo orthodontic tooth movement. Group III received nonfluoridated water and underwent orthodontic tooth movement. Group IV received nonfluoridated water and did not undergo orthodontic tooth movement. At the beginning of the experiment (T1), impressions were taken from the maxilla of the rats in groups I and III under general anesthesia, and a NiTi closed coil spring appliance was ligated between the left maxillary central incisors and maxillary first molar. The orthodontic force applied was approximately 75 g, and the duration of the experimental period was 18 days. During the experimental period, appliances were controlled daily. At the end of the experimental period (T2), the rats were sacrificed with an overdose of a ketamine/xylasine combination, and their impressions were obtained. The upper first molars were subsequently dissected for histological examination. Incisor–molar distance, number of osteoblasts, number of osteoclasts and periodontal ligament (PDL) space widths on the compression and tension sides were measured.

Statistical Analysis  All measurements were statistically analyzed with SPSS for Windows version 18.0 (SPSS Inc., Chicago, IL, USA). Repeated measures ANOVA and posthoc Tukey tests were used to compare the groups.

Results  No statistically significant difference was found with respect to the amount of tooth movement between the fluoridated and nonfluoridated groups ( p > 0.05). Orthodontic force application increased the number of osteoblasts at the tension sides and reduced it at the compression sides ( p < 0.001). An increased number of osteoclasts was observed in the nonfluoridated group relative to the fluoridated group ( p < 0.01).

Conclusions  No difference was observed with respect to the amount of tooth movement between the fluoridated and nonfluoridated groups. Fluoride significantly reduced the number of osteoclasts in the experimental groups.