Contour Augmentation by Means of Connective Tissue Grafting Versus Guided Bone Regeneration

Guided Bone Regeneration Clinical Trial

Official title:

A Randomized Controlled Trial Comparing Guided Bone Regeneration With Connective Tissue Graft to Re-establish Buccal Convexity at Implant Sites: Three-year Results.

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05143242
• Other study ID #: 23-186
• Status: Completed
• Phase: N/A
• Start date: March 2015
• Est. completion date: April 2021

Study information

• Verified date: December 2021
• Source: University Ghent
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The most frequent aesthetic complication following single implant treatment seems to be a lack of buccal convexity. This 'alveolar process deficiency' is the result of buccal bone remodeling following tooth extraction.

A traditional approach to treat alveolar process deficiency is guided bone regeneration (GBR), however post-operative complications such as swelling, bleeding and pain are common and the aesthetic outcome may not be optimal.

An alternative to the traditional GBR approach could be soft tissue contour augmentation using a connective tissue graft (CTG) at the buccal aspect. Possible advantages over GBR include less morbidity at the implant site, a superior aesthetic outcome since there is no need for vertical releasing incisions and less costs since there are no biomaterials to be used.

The primary study objective is to compare the GBR and CTG group in terms of 2 and 3 dimensional tissue alterations, focusing on the amount of tissue gain and volume stability over time. The secondary study objectives are morbidity, overall radiographic, clinical and aesthetic outcomes.

Description:

Aim:

This study aims to compare guided bone regeneration (GBR) with connective tissue graft (CTG) to re-establish buccal convexity at single implants.

Sample size calculation:

The sample size calculation was based on the primary study outcome (BSP) and was performed in SAS Power using the Satterthwaite t-test (De Bruyckere et al., 2018). The calculation was based on finding a mean difference of at least 0.5 mm between these groups with a standard deviation of 0.5 mm. This standard deviation was arbitrarily chosen given the lack of comparative studies. Alpha was set at 0.05 and the power was set at 0.80. This resulted in the inclusion of at least 17 patients per group. To compensate for possible drop-outs, 21 patients were included in each group.

Randomization and allocation concealment:

Patients were randomly assigned to the control group (GBR) or test group (CTG). Simple randomization was performed using sealed envelopes with an equal number of envelopes for every treatment group. Group allocation was revealed just prior to surgery by the surgeon and remained concealed for the evaluating investigator during the analytical stage of the project.

Surgical procedure:

In brief, a mucoperiosteal flap was raised in the control group by means of a midcrestal incision, sulcular incisions at both neighbouring teeth and a vertical parapapillary releasing incision at the distal neighbouring tooth. Following implant installation (NobelActive®, Nobel Biocare, Gothenburg, Sweden), the buccal concavity was augmented with deproteinized bovine bone mineral (DBBM) (Bio-Oss®; 0.25 - 1mm; Geistlich Biomaterials, Wolhusen, Switserland) and a collagen membrane (Creos® xenoprotect; 15x20mm; Nobel Biocare, Gothenburg, Sweden). Following apical release of the tissues, a cover screw was installed and primary wound closure was achieved (Seralon® 5/0, Serag Weissner, Naila, Germany). Aftercare included the use of a chlorhexidine rinse, systemic antibiotics (amoxicillin 1g, two times a day) and anti-inflammatory medication (ibuprofen 600mg) as deemed necessary by the patient. After 3 months, the implant was uncovered by means of a pouch procedure. A screw-retained provisional crown was placed as described by De Rouck et al. (2008), which was replaced by the permanent restoration (Procera® on ASC® abutment, Nobel Biocare, Gothenburg, Sweden) 3 months later.

The flap design in the test group was identical to the one in the control group, yet without a vertical parapapillary releasing incision. Instead of augmenting with DBBM, an appropriately sized CTG harvested from the palatal flap or palatal mucosa in the premolar area was pulled into the envelope and immobilized (Seralon® 5/0, Serag Weissner, Naila, Germany). Non-submerged healing was respected. Aftercare and prosthetic procedures were identical in both groups. All surgical treatments and provisional restorations were performed by the same clinician. Referring dentists made permanent restorations.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 42
• Est. completion date: April 2021
• Est. primary completion date: March 2020
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• At least 18 years old.

• Good oral hygiene defined as full-mouth plaque score = 25% (O'Leary et al.1972

• Presence of a single tooth gap in the anterior maxilla (15 - 25) with both neighbouring teeth present

• Failing tooth at least 3 months earlier removed

• Class I defect at the single tooth gap as clinically assessed (buccopalatal loss of tissue with a normal apicocoronal ridge height) (Seibert, 1983)

• Signed informed consent

• Buccopalatal bone dimension of at least 6 mm at the central and crestal aspect of the single tooth gap to ensure complete embedding of an implant by bone

Exclusion Criteria:

• Systemic diseases

• Smoking

• (History of) periodontal disease

• Untreated caries lesions

• Need for horizontal bone augmentation at the time of implant placement

Related Conditions & MeSH terms

• Guided Bone Regeneration

Intervention

Procedure:
• Hard tissue augmentation at the buccal aspect of single implants.
One or two releasing incisions are made. The periosteum is released and multiple bone perforations are made in the buccal bone prior to the application of deproteinized bovine derived xenograft. A Creos® membrane (Nobel Biocare, Gothenburg, Sweden) is used to cover the occlusal part of the alveolar crest and the xenograft particles. Finally, multiple single monofilament sutures are used for primary tension-free wound closure.
• Soft tissue augmentation at the buccal aspect of single implants.
A CTG is taken from the palate and transplanted to the buccal side between the alveolar bone and the buccal flap. The CTG is secured with single monofilament sutures.

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
University Ghent

References & Publications (28)

Akcali A, Schneider D, Ünlü F, Bicakci N, Köse T, Hämmerle CH. Soft tissue augmentation of ridge defects in the maxillary anterior area using two different methods: a randomized controlled clinical trial. Clin Oral Implants Res. 2015 Jun;26(6):688-95. doi: 10.1111/clr.12368. Epub 2014 Apr 10. — View Citation

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Buser D, Chappuis V, Bornstein MM, Wittneben JG, Frei M, Belser UC. Long-term stability of contour augmentation with early implant placement following single tooth extraction in the esthetic zone: a prospective, cross-sectional study in 41 patients with a 5- to 9-year follow-up. J Periodontol. 2013 Nov;84(11):1517-27. doi: 10.1902/jop.2013.120635. Epub 2013 Jan 24. — View Citation

Buser D, Chappuis V, Kuchler U, Bornstein MM, Wittneben JG, Buser R, Cavusoglu Y, Belser UC. Long-term stability of early implant placement with contour augmentation. J Dent Res. 2013 Dec;92(12 Suppl):176S-82S. doi: 10.1177/0022034513504949. Epub 2013 Oct 24. — View Citation

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Chappuis V, Rahman L, Buser R, Janner SFM, Belser UC, Buser D. Effectiveness of Contour Augmentation with Guided Bone Regeneration: 10-Year Results. J Dent Res. 2018 Mar;97(3):266-274. doi: 10.1177/0022034517737755. Epub 2017 Oct 26. — View Citation

Cosyn J, Eghbali A, De Bruyn H, Collys K, Cleymaet R, De Rouck T. Immediate single-tooth implants in the anterior maxilla: 3-year results of a case series on hard and soft tissue response and aesthetics. J Clin Periodontol. 2011 Aug;38(8):746-53. doi: 10.1111/j.1600-051X.2011.01748.x. — View Citation

Cosyn J, Eghbali A, De Bruyn H, Dierens M, De Rouck T. Single implant treatment in healing versus healed sites of the anterior maxilla: an aesthetic evaluation. Clin Implant Dent Relat Res. 2012 Aug;14(4):517-26. doi: 10.1111/j.1708-8208.2010.00300.x. Epub 2010 Jul 17. — View Citation

De Bruyckere T, Cabeza RG, Eghbali A, Younes F, Cleymaet R, Cosyn J. A randomized controlled study comparing guided bone regeneration with connective tissue graft to reestablish buccal convexity at implant sites: A 1-year volumetric analysis. Clin Implant Dent Relat Res. 2020 Aug;22(4):468-476. doi: 10.1111/cid.12934. Epub 2020 Jul 19. — View Citation

De Bruyckere T, Eeckhout C, Eghbali A, Younes F, Vandekerckhove P, Cleymaet R, Cosyn J. A randomized controlled study comparing guided bone regeneration with connective tissue graft to re-establish convexity at the buccal aspect of single implants: A one-year CBCT analysis. J Clin Periodontol. 2018 Nov;45(11):1375-1387. doi: 10.1111/jcpe.13006. — View Citation

De Bruyckere T, Eghbali A, Younes F, De Bruyn H, Cosyn J. Horizontal stability of connective tissue grafts at the buccal aspect of single implants: a 1-year prospective case series. J Clin Periodontol. 2015 Sep;42(9):876-882. doi: 10.1111/jcpe.12448. Epub 2015 Sep 16. — View Citation

De Rouck T, Collys K, Cosyn J. Single-tooth replacement in the anterior maxilla by means of immediate implantation and provisionalization: a review. Int J Oral Maxillofac Implants. 2008 Sep-Oct;23(5):897-904. Review. — View Citation

Eghbali A, De Bruyn H, Cosyn J, Kerckaert I, Van Hoof T. Ultrasonic Assessment of Mucosal Thickness around Implants: Validity, Reproducibility, and Stability of Connective Tissue Grafts at the Buccal Aspect. Clin Implant Dent Relat Res. 2016 Feb;18(1):51-61. doi: 10.1111/cid.12245. Epub 2014 Jul 17. — View Citation

Eghbali A, Seyssens L, De Bruyckere T, Younes F, Cleymaet R, Cosyn J. A 5-year prospective study on the clinical and aesthetic outcomes of alveolar ridge preservation and connective tissue graft at the buccal aspect of single implants. J Clin Periodontol. 2018 Dec;45(12):1475-1484. doi: 10.1111/jcpe.13018. Epub 2018 Nov 5. — View Citation

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Thoma DS, Bienz SP, Figuero E, Jung RE, Sanz-Martín I. Efficacy of lateral bone augmentation performed simultaneously with dental implant placement: A systematic review and meta-analysis. J Clin Periodontol. 2019 Jun;46 Suppl 21:257-276. doi: 10.1111/jcpe.13050. — View Citation

Thoma DS, Buranawat B, Hämmerle CH, Held U, Jung RE. Efficacy of soft tissue augmentation around dental implants and in partially edentulous areas: a systematic review. J Clin Periodontol. 2014 Apr;41 Suppl 15:S77-91. doi: 10.1111/jcpe.12220. Review. — View Citation

Thoma DS, Naenni N, Benic GI, Hämmerle CH, Jung RE. Soft tissue volume augmentation at dental implant sites using a volume stable three-dimensional collagen matrix - histological outcomes of a preclinical study. J Clin Periodontol. 2017 Feb;44(2):185-194. doi: 10.1111/jcpe.12635. Epub 2017 Jan 3. — View Citation

Tonetti MS, Cortellini P, Graziani F, Cairo F, Lang NP, Abundo R, Conforti GP, Marquardt S, Rasperini G, Silvestri M, Wallkamm B, Wetzel A. Immediate versus delayed implant placement after anterior single tooth extraction: the timing randomized controlled clinical trial. J Clin Periodontol. 2017 Feb;44(2):215-224. doi: 10.1111/jcpe.12666. Epub 2017 Jan 31. — View Citation

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* Note: There are 28 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Buccal soft tissue profile	The volumetric analysis software (Swissmeda/SMOP, Zürich, Switzerland) calculated a mean dimensional change (mm3) within the AOI (area of interest) for each patient at T5 (3 years). Given the variable size in AOI (mm2) among patients, the mean dimensional change per area was transformed to a mean linear change in buccal soft tissue profile (BSP) in mm.	Year 1 and 3
Secondary	Midfacial recession	Midfacial recession was registered between 6 months, 1 year and 3 years on the basis of digital surface models in STL format superimposed and imported in designated software (Swissmeda/SMOP, Zürich, Switzerland). Midfacial recession was calculated by subtracting the data from 1 and 3 years to 6 months of follow-up.	Month 6; Year 1 and 3
Secondary	Buccal bone thickness	The thickness of the buccal bone was measured (in mm) at t2 (1 year) and t3 (3 years) perpendicular to the long axis of the implant. Buccal bone was measured from the implant surface to the bone-soft tissue interface at 3 levels.	Year 1 and 3
Secondary	Buccal soft tissue thickness	The thickness of the soft tissues was measured (in mm) at t2 (1 year) and t3 (3 years) perpendicular to the long axis of the implant. Buccal soft tissue thickness was measured from the bone-soft tissue interface to the buccal soft tissue outline at the same levels as buccal bone thickness.	Year 1 and 3
Secondary	Pink Esthetic Score	The PES awards 7 parameters: mesial papilla, distal papilla, soft tissue level, soft tissue contour, alveolar process deficiency, soft tissue colour, soft tissue texture. Each parameter is assessed with a 0-1-2 score, yielding a PES score ranging from 0 (worst aesthetic outcome) to 14 (perfect aesthetic outcome).	Year 1 and 3
Secondary	Mucosal Scarring Index	The MSI is a composite index based on five parameters: width, height/contour, colour, suture marks and overall appearance. Each parameter is assessed with a 0-1-2 score, yielding an MSI score ranging from 0 (no scar) to 10 (most extreme scar).	Year 1 and 3
Secondary	Marginal bone loss	Marginal bone loss was recorded at the mesial and distal aspect of each implant. The distance from the implant-abutment interface to the first bone-to-implant contact (so-called bone level) was assessed on peri-apical radiographs taken with the long-cone paralleling technique. Mesial and distal values were averaged to receive one value per implant.	Year 1 and 3
Secondary	Probing depth	Probing depth was registered at four locations (mesiobuccal, buccal, distobuccal and palatal) around the implant to the nearest 0.5 mm. A mean value was calculated per implant.	Year 1 and 3
Secondary	Plaque	Plaque was assessed at four locations (mesiobuccal, buccal, distobuccal and palatal) around the implant. Each location was scored 0 or 1 (the absence or presence of plaque, respectively). Plaque was expressed as a percentage.	Year 1 and 3
Secondary	Bleeding on probing	Bleeding on probing was assessed at four locations (mesiobuccal, buccal, distobuccal and palatal) around the implant. Each location was scored 0 or 1 (the absence or presence of bleeding, respectively). Bleeding on probing was expressed as a percentage.	Year 1 and 3