Clinical trial NCT05143242: Contour Augmentation by Means of Connective Tissue Grafting Versus Guided Bone Regeneration
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.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Guided Bone Regeneration
Keywords: connective tissue graft
dental implant
guided bone regeneration
single tooth
Lead sponsor: University Ghent
Sponsor class: OTHER
First posted: 2021-12-03
Enrollment: 42
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: randomized clinical trial
Primary purpose: TREATMENT

Brief 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.

Detailed 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.

Eligibility criteria: 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

Primary outcomes:
measure: Buccal soft tissue profile
timeFrame: Year 1 and 3
Secondary outcomes:
measure: Midfacial recession
timeFrame: Month 6; Year 1 and 3
measure: Buccal bone thickness
timeFrame: Year 1 and 3
measure: Buccal soft tissue thickness
timeFrame: Year 1 and 3
measure: Pink Esthetic Score
timeFrame: Year 1 and 3
measure: Mucosal Scarring Index
timeFrame: Year 1 and 3
measure: Marginal bone loss
timeFrame: Year 1 and 3
measure: Probing depth
timeFrame: Year 1 and 3
measure: Plaque
timeFrame: Year 1 and 3
measure: Bleeding on probing
timeFrame: Year 1 and 3
Other outcomes:
Locations:
Study officials:
References:
citation: Akcali A, Schneider D, Unlu F, Bicakci N, Kose T, Hammerle 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.
citation: Araujo MG, Lindhe J. Dimensional ridge alterations following tooth extraction. An experimental study in the dog. J Clin Periodontol. 2005 Feb;32(2):212-8. doi: 10.1111/j.1600-051X.2005.00642.x.
citation: Buser D, Weber HP, Lang NP. Tissue integration of non-submerged implants. 1-year results of a prospective study with 100 ITI hollow-cylinder and hollow-screw implants. Clin Oral Implants Res. 1990 Dec;1(1):33-40. doi: 10.1034/j.1600-0501.1990.010105.x.
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.
citation: 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.
citation: 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.
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.
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.
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.
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.
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.
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.
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.
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.
citation: Furhauser R, Florescu D, Benesch T, Haas R, Mailath G, Watzek G. Evaluation of soft tissue around single-tooth implant crowns: the pink esthetic score. Clin Oral Implants Res. 2005 Dec;16(6):639-44. doi: 10.1111/j.1600-0501.2005.01193.x.
citation: Hammerle CH, Araujo MG, Simion M; Osteology Consensus Group 2011. Evidence-based knowledge on the biology and treatment of extraction sockets. Clin Oral Implants Res. 2012 Feb;23 Suppl 5:80-2. doi: 10.1111/j.1600-0501.2011.02370.x.
citation: Hanser T, Khoury F. Alveolar Ridge Contouring with Free Connective Tissue Graft at Implant Placement: A 5-Year Consecutive Clinical Study. Int J Periodontics Restorative Dent. 2016 Jul-Aug;36(4):465-73. doi: 10.11607/prd.2730.
citation: O'Leary TJ, Drake RB, Naylor JE. The plaque control record. J Periodontol. 1972 Jan;43(1):38. doi: 10.1902/jop.1972.43.1.38. No abstract available.
citation: Schneider D, Ender A, Truninger T, Leutert C, Sahrmann P, Roos M, Schmidlin P. Comparison between clinical and digital soft tissue measurements. J Esthet Restor Dent. 2014 May-Jun;26(3):191-9. doi: 10.1111/jerd.12084. Epub 2013 Dec 17.
citation: Seibert JS. Reconstruction of deformed, partially edentulous ridges, using full thickness onlay grafts. Part I. Technique and wound healing. Compend Contin Educ Dent (Lawrenceville). 1983 Sep-Oct;4(5):437-53. No abstract available.
citation: Thoma DS, Buranawat B, Hammerle 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.
citation: Thoma DS, Naenni N, Benic GI, Hammerle 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.
citation: Thoma DS, Bienz SP, Figuero E, Jung RE, Sanz-Martin 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.
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.
citation: Van der Weijden F, Dell'Acqua F, Slot DE. Alveolar bone dimensional changes of post-extraction sockets in humans: a systematic review. J Clin Periodontol. 2009 Dec;36(12):1048-58. doi: 10.1111/j.1600-051X.2009.01482.x.
citation: Wessels R, De Roose S, De Bruyckere T, Eghbali A, Jacquet W, De Rouck T, Cosyn J. The Mucosal Scarring Index: reliability of a new composite index for assessing scarring following oral surgery. Clin Oral Investig. 2019 Mar;23(3):1209-1215. doi: 10.1007/s00784-018-2535-6. Epub 2018 Jul 3.
citation: Wiesner G, Esposito M, Worthington H, Schlee M. Connective tissue grafts for thickening peri-implant tissues at implant placement. One-year results from an explanatory split-mouth randomised controlled clinical trial. Eur J Oral Implantol. 2010 Spring;3(1):27-35.
citation: Zeltner M, Jung RE, Hammerle CH, Husler J, Thoma DS. Randomized controlled clinical study comparing a volume-stable collagen matrix to autogenous connective tissue grafts for soft tissue augmentation at implant sites: linear volumetric soft tissue changes up to 3 months. J Clin Periodontol. 2017 Apr;44(4):446-453. doi: 10.1111/jcpe.12697. Epub 2017 Feb 11.