Soft tissue regeneration around healing abutments

Dr. M. Beldoch & Dr. R. Valentin, Köln

Abstract

Objectives: The aim of this study was to evaluate gingival regeneration around healing abutments /

gingiva formers on osseointegrated implants.

Material and methods: 60 implant sites (19 patients, 13 male) were evaluated concerning the

thickness of the gingiva. Baseline measurements took place by bone sounding during implant surgery

(measurement 1 – M1), following measurements after submerged healing during implant uncovering

(measurement 2 – M2) and insertion of the final prosthetics (measurement 3 – M3). Patients

suffering from peri-implant mucositis were excluded. IMPLA Cylindrical Implants (Schütz Dental

GmbH, Rosbach, Germany) with a diameter of 3.6mm (in two cases 4.5mm) and IMPLA gingiva

formers cylindrical (Schütz Dental GmbH, Rosbach, Germany) (hex connection or cone connection,

polished titan grade 5) were used. Statistical analysis compared the means of the three

measurements using a repeated measures ANOVA and Tukey-Kramer-Test.

Results: Evaluation showed significant increase of gingival thickness throughout the treatment

(+.43mm, p < .001). After implantation an increased gingival thickness has been measured prior to

implant uncovering and insertion of the healing abutment (+.27mm, p < .001). After insertion of the

healing abutments additional gain in gingival thickness was measured (+.17mm, p < .001). No side

effects have been registered.

Conclusion: After implantation with submerged implant healing a gain of gingival thickness can be

registered. The gain of gingiva thickness can only be considered partially due to gingival formers as

additional .27mm were measured before uncovering the implants and before insertion of healing

abutments and .17mm afterwards. Therefore – within the limits of this study – it can be suggested

that after an initial healing phase with possible postoperative granulation and keloid formation the

soft-tissue still gains thickness around healing abutments while it is formed by the used gingival

formers to adapt to the final prosthetic restauration.

Introduction:

Peri-implant soft tissues are essential for osseointegration as well as an optimal esthetic outcome. A

sufficient height of the gingiva around the implant is essential for esthetic purposes as well as for

hygienic purposes – peri-implant soft tissues can be only be formed / modelled sufficiently if the

gingiva is not too thin.

Over 65% of patient with implants suffer from peri-implant mucositis during a 5 year timeframe

[Konstantinidis et. al., 2015]. In order to reduce plaque retention sites and furthermore reduce peri-

implant inflammation as mucositis and peri-implantitis as well as a positive esthetic outcome,

gingival modelling around abutments and gingival formers needs to be optimized. Therefor this study

objected to examine the thickness of the gingiva after implantation with submerged healing as well

as the influence of a healing abutment after implant uncovering.

Material and Methods:

19 patients (13 male, 6 female) who received at least one implant (IMPLA Cylindrical, Schütz Dental

GmbH) were examined at implant surgery (measurement 1 – M1), implant unvocering after

submerged healing (measurement 2 – M2) and insertion of the final prosthetics (measurement 3 –

M3). Patients were selected randomly in a dental office in Köln, Germany, between 08/2012 and

05/2014. All surgeries were performed by one experienced surgeon. A total of 60 implant sites were

examined.

Gingival height was measured just after incision at implant surgery with a PCPUNC15 probe (HU-

Friedy) [Fig. 1]. The soft tissue height was recorded from the top of the bone to the gingival border.

IMPLA Cylindrical implants were inserted (58 with a diameter of 3.6mm and two with a diameter of

4.2mm). After submerged healing (13-77 weeks, mean 32.6 weeks) implants were uncovered and

gingival thickness was measured again [Fig. 2 & Fig. 3]. Implants were covered by a healing abutment

/ gingival former (IMPLA gingiva formers cylindrical, Schütz Dental GmbH) [Fig. 5 & Fig. 6] with either

a hex or cone connection. When inserting the final prosthetics a third measurement took place

(measurement 3 – M3, 22-111 weeks after implantation, mean 57.3 weeks).

No side effects were registered, especially at no implant site a peri-implant mucositis has been

diagnosed.

Statistical analysis was performed using a repeated measures ANOVA and a Tukey-Kramer-Test.

Results:

Evaluation showed significant increase of gingival thickness throughout the treatment (M1 vs M3

showed a mean difference of .43mm, p < .001, 22-111 weeks after implantation (mean 57.3 weeks)).

During the healing process after implantation an increased gingival thickness has been measured

prior to implant uncovering and insertion of the healing abutment (M1 vs M2 showed a mean

difference of .27mm, p < .001, 13-77 weeks after implantation (mean 32.6 weeks)). After insertion of

the healing abutments additional gain in gingival thickness was measured (M2 vs M3 showed a mean

difference of .17mm, p < .001) [Table 1, Table 2, Table 3]. No side effects have been registered.

M1 M2 M3

mean (mm) 2.49 2.76 2.93

standard deviation .55 .56 .55

n 60 60 60

Table 1: descriptive statistics

comparison

comparison mean difference (mm) P value

M1 vs M2 .27 P<0.001 ***

M1 vs M3 .43 P<0.001 ***

M2 vs M3 .17 P<0.001 ***

*** The P value is < 0.0001, considered extremely significant.

Table 2: comparison

95% confidence interval

Difference mean difference (mm) 95% confidence interval

M1 vs M2 .27 0.35 - 0.19

M1 vs M3 .43 0.51 - 0.35

M2 vs M3 .17 0.25 - 0.09

Table 3: 95% confidence interval

Discussion:

Wound healing is a complex process modified by many different factors as oxygenation, infection,

age and sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition

[Guo & Dipietro, 2010]. It is known that peri-implant soft-tissues heal and differentiate similar to natural

gingiva [Mackenzie & Tonetti, 1995]. Therefore a postoperative gain in gingival thickness was

expectable due to granulation and possible keloid formation. After uncovering the implant though, the

use of gingival formers allows modelling the soft tissues to fit the final prosthetics onto the implant

abutment. It is known that Titanium leads to an adherence of gingival fibroblast [Dorkhan et al., 2014].

In this study the used titanium healing abutments lead to an increased height of gingiva around the

implant. It can be suggested that due to the adherence of gingival fibroblast and common form of

gingival formers the height of soft-tissue around implants can be modelled in horizontal as well in

vertical direction.

In summary it can be said that after implantation with submerged implant healing a gain of gingival

thickness can be registered. The gain of gingiva thickness can only be considered partially due to

gingival formers as additional .27mm were measured before uncovering the implants and before

insertion of healing abutments and .17mm afterwards. Therefore – within the limits of this study – it

can be suggested that after an initial healing phase with possible postoperative granulation and

keloid formation the soft-tissue still gains thickness around healing abutments while it is formed by

the used gingival formers to adapt to the final prosthetic restauration.

Fig. 1: measurement after incision at implant surgery

Fig. 2: measurement after implant uncovering

Fig. 3: measurement at a healing abutment

Fig. 4: PCPUNC15 (HU-Friedy)

Fig. 5: Impla gingiva formers (hex connection)

Fig. 6: Impla gingiva formers (cone connection)

Literature

Dorkhan, Marjan; Yücel-Lindberg, Tülay; Hall, Jan; Svensäter, Gunnel; Davies, Julia R. (2014): Adherence of human

oral keratinocytes and gingival fibroblasts to nano-structured titanium surfaces. In: BMC Oral Health 14, S. 75. DOI:

10.1186/1472-6831-14-75.

Guo, S.; Dipietro, L. A. (2010): Factors affecting wound healing. In: J. Dent. Res. 89 (3), S. 219–229. DOI:

10.1177/0022034509359125.

Konstantinidis, Ioannis K.; Kotsakis, Georgios A.; Gerdes, Sebastian; Walter, Michael Horst (2015): Cross-sectional

study on the prevalence and risk indicators of peri-implant diseases. In: Eur J Oral Implantol 8 (1), S. 75–88.

Mackenzie, I. C.; Tonetti, M. S. (1995): Formation of normal gingival epithelial phenotypes around osseo-integrated

oral implants in humans. In: J. Periodontol. 66 (11), S. 933–943. DOI: 10.1902/jop.1995.66.11.933.

Corresponding author:

Dr. Matthias Beldoch Zahnarztpraxis Valentin & Partner Deutzer Freiheit 95-97 50679 Köln, Germany info@zahnarzt-beldoch.de