04 JANUARY 2020
Injectableplatelet-richfibrinand microneedlingfor gingival
augmentationin thin periodontalphenotype:A randomized
controlled clinical trial
Zeliha Betul Ozsagir, Ebru Saglam, Berza Sen Yilmaz, Joseph Choukroun, Mustafa Tunali

AIM
To evaluate the effect of gingival thickness (GT) and
keratinized tissue width (KTW) using injectable platelet
rich fibrin (i-PRF) alone and with microneedling (MN) in
individuals with thin periodontal phenotypes.

CLINICAL RELEVANCE
Scientific rationale
• Thin gingival thickness is an important predisposing
factor for gingival recessions.
• Importance of phenotype in gingival
recession and root coverage procedures.
• Guide clinicians to use injectable platelet-rich fibrin with
and without microneedling to modify phenotype before
Periodontal surgery/orthodontics.

Principal findings
• Predictable and safe.
• Increased gingival thickness was found to be significant
in favour of microneedling with injectable platelet rich
fibrin.
Practical implications
• Using injectable platelet-rich fibrin before periodontal
plastic surgery/orthodontics may improve the efficiency of
these procedures.

INTRODUCTION
The periodontal phenotype has been defined as the
combination of gingival phenotype and buccal bone plate
thickness (bone morphotype) (Jepsen et al., 2018).
Bone morphotype measurement with cone-beam computed
tomography has not been recommended (Jepsen et al., 2018)
So there is a correlation between the GT and the buccal
bone plate (Ghassemian et al., 2016; Zweers, Thomas, Slot,
Weisgold, & Van derWeijden, 2014)
Gingival phenotype refers to gingival thickness (GT) and
keratinized tissue width (KTW) (Muller & Eger, 2002).

Platelet-rich fibrin (PRF) has been developed by
centrifugation of blood obtained in glass tubes without
anticoagulants and activators.
Injectable platelet-rich fibrin (i-PRF) has been produced by
changing the type of the tube, centrifugation time and speed;
specifically, the blood is centrifuged in plastic tubes at
700 rpm for 3 min.
(Miron & Choukroun, 2017).

Microneedling (MN) is also known as “percutaneous collagen
induction therapy.”
Microinjuries created by MN result in minimal superficial
bleedings and create a wound-healing cascade from which
various growth factors, such as platelet-derived growth
factors, transforming growth factors, connective tissue
growth factor and fibroblast growth factors, are released.

Due to these positive effects of MN and i-PRF on the
biological potential, neoangiogenesis, neocollagenesis and
wound healing, this study evaluated the effects of i-PRF and
i-PRF in combination with MN on the GT and KTW
parameters of the periodontal phenotype in individuals with
thin phenotypes.

MATERIALS AND METHODS
6-month follow-up, single-blind, randomized, prospective,
split-mouth report.
All individuals who participated in the study were informed
about the objective and methods of the study and signed
informed consent forms.

PATIENT SELECTION
After 30% drop-out rate 38 individuals with thin
phenotypes & buccal
dehiscence on CBCT after
orthodontic treatment on
mandibular anterior teeth.
Five female patients were
excluded
The study was completed with 198 mandibular anterior teeth
from 33 patients (28 females, 5 males) aged 18–34 years
(mean:22.2 years).
4 for not attending the
control sessions and 1due to
lack of oral hygiene in the
mandibular anterior teeth

Inclusion criteria
(a) Age ≥ 18 years and no systemic disease or pregnancy or
lactation
(b) Non-smoker
(c) Full mouth plaque index (PI) and full-mouth bleeding on
probing (BOP) score of ≤ 15%
(d) GT of the mandibular anterior teeth < 0.8 mm; gingival
index (GI) of < 1 and dehiscence in mandibular anterior teeth
detected in CBCT
(e) No malocclusion, crowding, fillings, missing or
supernumerary mandibular anterior teeth
(f) No blood-borne conditions

Exclusion criteria
(a) Active orthodontic treatment
(b) Previous periodontal surgery
(c) Systemic disease
(d) Use of blood thinners
(e) Use of any drugs that might lead to gingival enlargement
(f) Mucogingival stress, bruxism

All received oral hygiene instructions on correct non-
traumatic toothbrushing technique (roll) using
ultra-soft toothbrush and full-mouth non-surgical periodontal
therapy before the clinical examination to check for any
potential gingival inflammation.

Determination of periodontal phenotype
Pt. with high periodontal probe visibility in mandibular
anterior teeth were identified and GT was measured using
transgingival probing technique.
GT of ≤ 0.8 mm were diagnosed with thin phenotype.
(Baldi et al., 1999)
CBCT of these patients were assessed and patients, with
buccal bone dehiscence extending from 1/2-1/3 apical to
mandibular anterior tooth roots, were included in the study.

CLINICAL MEASUREMENTS
PI (Silness & Löe, 1964);
GI (Löe & Silness, 1963);
PD;
BOP (Ainamo & Bay, 1975);
Clinical attachment loss (CAL);
Gingival recession depth (RD) recorded at 6 sites
(mesiobuccal, mid-buccal, disto-buccal, mesio-palatal/
lingual, mid-palatal/lingual, distopalatal/lingual) per tooth.
10-mm periodontal probe was used.

Keratinized tissue width (KTW):
• Used Schiller's iodine solution.
• Used periodontal probe with a silicon disc (Stop Card &
Endo-Stops).
• The distance from the free gingival margin (the lower end of
the silicone disc) to the mucogingival junction was measured
through the vestibular midpoint.
Gingival thickness (GT):
• From the apical 1.5 mm of the gingival margin.
• No:15 endodontic spreader was placed in the centre of a
3-mm-diameter silicone disc.
• Spreader inserted perpendicularly from the vestibular
midpoint at 1.5 mm, apical of the gingival margin.

•The penetration depth between the silicone disc and the
spreader tip was measured (Zucchelli et al., 2010).
KTW and GT were recorded per mandibular anterior tooth.
The measurements were repeated twice at 10-min intervals
and recorded by taking the average.
Clinical periodontal measurements, KTW and GT value of
female patients were taken on the 1st day after menstruation.
GT and KTW parameters were measured using a
digital calliper with a sensitivity of 0.01 mm.

Preparation of i-PRF
Venous blood sample that was taken once for each patient
using a 20-ml injector was separated into two i-PRF tubes.
10 ml each containing no anticoagulant and centrifuged at
room temperature for 3 min at 700 rpm (60 g force) with
Choukroun PRF Duo Centrifuge.
The i-PRFs obtained were placed in 2.5 cc dental injectors.
The 27-gauge dental injector needles were used for injection
of i-PRF.

Microneedling
Thirty-gauge (0.255 mm) lancet needles were vertically
inserted into the tissue until the hard tissue was reached.
MN was carried out on keratinized gingiva from the mesial
line of the central tooth to the distal part of the canine tooth to
be treated with the help of a lancet.
The keratinized gingiva was vertically and horizontally
measured in mm.
By establishing a ratio and proportion, the
number of microchannels in the region to be treated was
calculated to be 250 microchannels in 1 cm2

Administration protocol
On one side of the mandibular anterior region, only i-PRF was
performed, and on the other side, both MN and i-PRF
procedures were performed.
Topical anaesthetic gel was applied to the patient's mandibular
anterior region before each GT measurement and i-PRF-MN
application.

MN + i-PRF Group: After MN was applied in keratinized
tissue, i-PRF was injected into the apical region of the
mucogingival margin in alveolar mucosa of the study area.
i-PRF Group: Only i-PRF was injected into the apical region
of the mucogingival margin in alveolar mucosa of the study
area.
To control bleeding due to the needle tip after the procedure, a
saline-soaked sponge was placed between the lip and the
gingiva.
Approximately 15 min later, the sponge was removed from
the administration site.

A total of 4 sessions of MN and i-PRF procedure were
administered to individuals at 10-day intervals
The clinical measurements of the patients were taken every
month during the follow-up sessions for 6 months after the
procedures

Statistical analyses
Software used (version12.7.7; MedCalc Software bvba,
Ostend; 2013).
Shapiro–Wilk test was used to evaluate the normality of the
data distribution.
Mann–Whitney U test for inter-group statistical comparisons.
Friedman test for Comparisons of the intra-group values (time
-varying multiple dependent variables).
Bonferroni-corrected Wilcoxon's signed-rank test for post hoc
pairwise comparisons.
Spearman's rank correlation test was used to identify
relationships between GT, KTW and clinical periodontal
parameters.

RESULTS
GT is primer outcome parameters, and KTW, clinical
periodontal measurements and correlation are seconder
outcome parameters of this current study.
GT
In the intra-group comparisons:
• Statistically significant difference between the GT
measurements in both groups of all mandibular teeth, central
tooth, lateral tooth and canine tooth (p < .001).

•Statistically significant increase was observed between all
follow-up measurements compared with the baseline in both
groups of all mandibular teeth, central tooth, lateral tooth and
canine tooth (p < .0023).
In the inter-group comparisons:
•A significant difference was found between groups only at
6th month with a higher GT increase in favour of the MN +
i-PRF group of all mandibular teeth p = .007.

KTW
In the intra-group comparisons:
•There was a statistically significant difference between the
GT measurements only in MN + i-PRF group of all
mandibular teeth, central tooth, lateral tooth and canine tooth
(p < .001).
In the inter-group comparisons:
•There were no statistically significant differences between
the both groups of all mandibular teeth, central tooth, lateral
tooth and canine tooth (p > .05).

Clinical periodontal indexes
In the intra-group comparisons:
•There was a statistically significant difference between all
measurements in the PI, PD, BOP and CAL parameters, and it
was found that the baseline value was higher (p < .001).
Correlation
No statistically significant correlation at baseline–month 1,
baseline–month 3 and baseline–month 6.

DISCUSSION
The increases in the GT level due to both the i-PRF and MN +
i-PRF procedures were statistically significant.
The group that received MN to increase GT had a statistically
significant increase at 6 months compared with the group that
received only i-PRF.
A statistically significant increase in KTW was observed only
in the MN + i-PRF group, it is thought that it is not clinically
important because of the minimal increase.
Both procedures were more effective in increasing GT rather
than KTW.

The periodontal phenotype shows a stronger correlation
with GT rather than KTW and papilla height. Therefore, GT
was chosen as the main determinant parameter in this study.
It was reported that ultrasound and transgingival probing
yielded sufficient results for GT measurement in the
mandibular central teeth, transgingival probing was preferred
considering the cost, accuracy and reproducibility of this
approach.

A topical anaesthetic was administered prior to the MN/i-PRF
procedures and GT measurement using transgingival probing,
since local anaesthesia injection may mislead thickness
measurement due to storage in the tissue, and the
vasoconstrictor substances could affect the distribution of i-
PRF to be injected into the region
The correlation between GT and gender, it was indicated that
the incidence of the thin phenotype is higher in females than
males.

Four sessions of i-PRF and MN + i-PRF were performed at
10-day intervals in this present study; considering the current
MN literature, total collagen production during the wound
healing process peaked within 7–14 days.
In addition, the PRF resorption time was 7–11 days, and
growth factor release from i-PRF occurred at 10 days.

CONCLUSION
Current results obtained from a group of thin phonotype
patients showed that applying i-PRF and MN + i-PRF may
increase GT even without surgical periodontal procedures. It
is also thought that MN has an additional effect on the
increase in GT. Further studies will be useful to clarify this
new technique and the limitations.

REFERENCES