Clinical Outcomes of Immediate Implants With or Without a Volume-stable Collagen Matrix

Edentulous Alveolar Ridge Clinical Trial

Official title:

Clinical Outcomes of Immediate Implants With or Without a Volume-stable Collagen Matrix: a Randomized Controlled Clinical Trial

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05081284
• Other study ID #: 19228
• Status: Recruiting
• Phase: N/A
• Start date: November 1, 2021
• Est. completion date: November 2025

Study information

• Verified date: May 2024
• Source: University of Pisa
• Contact: Antonio Barone, DDS
• Phone: 050993327
• Email: antonio.barone[@]unipi.it
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The purpose of this study is to evaluate the soft tissue clinical results in patients that received, or not, a soft tissue augmentation around dental implant inserted immediately after the extraction.

Description:

After being informed about the study and potential risks, all patients giving written informed consent will undergo a screening period to determinate eligibility for study entry. Patients who meet eligibility requirements will be randomized in this single blinded(investigator) study.

Group (Test) will receive immediate implant after extraction and a soft tissue augmentation with a collagen matrix.

Group (Control) will receive only immediate implant after extraction without soft tissue augmentation.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 40
• Est. completion date: November 2025
• Est. primary completion date: November 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Presence of a single failing tooth in the esthetic region (second premolar to contralateral second premolar), the adjacent teeth should be present and without any dental pathologies.

Exclusion Criteria:

• Patients who are heavy smokers (more than 10 cigarettes/day);

• Patients who suffer from any systemic diseases that could negatively influence wound healing;

• Patients who received head and neck radiation treatment;

• Patients who have a full contraindication to implant surgery;

• Patients who have uncontrolled periodontal disease;

• Patients who show a full mouth plaque and bleeding score higher than 25%;

• Patients who have deficient extraction sockets according to the classification of Juodzbalys et al. 2008.

• Patients with known allergy, sensitivity or intolerance to collagen

• Patients who are pregnant or who are breastfeeding

Related Conditions & MeSH terms

• Edentulous Alveolar Ridge
• Mouth, Edentulous

Intervention

Device:
• Volume-stable collagen matrix Geistlich Fibro-Gide®
After tooth extraction and implant insertion the Test group will receive a soft tissue augmentation on the buccal side oh the implant. an envelop flap will be raised and a volume-stable collagen graft will be stabilized with sutures. Control group will not receive soft tissue augmentation.

Locations

Country	Name	City	State
Italy	U.O. Odontostomatologia e Chirurgia del Cavo Orale	Pisa

Sponsors (1)

Lead Sponsor	Collaborator
University of Pisa

Country where clinical trial is conducted

Italy, 

References & Publications (10)

Bittner N, Planzos L, Volchonok A, Tarnow D, Schulze-Spate U. Evaluation of Horizontal and Vertical Buccal Ridge Dimensional Changes After Immediate Implant Placement and Immediate Temporization With and Without Bone Augmentation Procedures: Short-Term, 1 — View 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. — View Citation

Cairo F, Barbato L, Tonelli P, Batalocco G, Pagavino G, Nieri M. Xenogeneic collagen matrix versus connective tissue graft for buccal soft tissue augmentation at implant site. A randomized, controlled clinical trial. J Clin Periodontol. 2017 Jul;44(7):769 — View Citation

De Rouck T, Eghbali R, Collys K, De Bruyn H, Cosyn J. The gingival biotype revisited: transparency of the periodontal probe through the gingival margin as a method to discriminate thin from thick gingiva. J Clin Periodontol. 2009 May;36(5):428-33. doi: 10 — View 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. — View Citation

Jemt T. Regeneration of gingival papillae after single-implant treatment. Int J Periodontics Restorative Dent. 1997 Aug;17(4):326-33. — View Citation

Mombelli A, van Oosten MA, Schurch E Jr, Land NP. The microbiota associated with successful or failing osseointegrated titanium implants. Oral Microbiol Immunol. 1987 Dec;2(4):145-51. doi: 10.1111/j.1399-302x.1987.tb00298.x. No abstract available. — View Citation

Pjetursson BE, Thoma D, Jung R, Zwahlen M, Zembic A. A systematic review of the survival and complication rates of implant-supported fixed dental prostheses (FDPs) after a mean observation period of at least 5 years. Clin Oral Implants Res. 2012 Oct;23 Su — View Citation

van der Meulen MJ, Lobbezoo F, John MT, Naeije M. [Oral health impact profile. an instrument for measuring the impact of oral health on the quality of life]. Ned Tijdschr Tandheelkd. 2011 Mar;118(3):134-9. doi: 10.5177/ntvt.2011.03.10178. Dutch. — View 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 — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Soft Tissue Thickness (STT)	Measured at 3 and 6 mm from the free gingival margin using a 15-endodontic file and a rubber disk. The file will advance perpendicularly through the soft tissue until the first point of bone contact. Thickness will be measured to the nearest 0.1 mm using a caliper. The rubber disk stop will be then placed in tight contact with the soft tissue surface and fixed with a drop of cyanocrylic adhesive. After file removal, the distance between file tip and the silicon stop will be measured using a digital caliper with 0.01 mm of accuracy. (Cairo et al. 2017; Bittner et al. 2020)	T0a: baseline before surgery
Primary	Soft Tissue Thickness (STT)	Measured at 3 and 6 mm from the free gingival margin using a 15-endodontic file and a rubber disk. The file will advance perpendicularly through the soft tissue until the first point of bone contact. Thickness will be measured to the nearest 0.1 mm using a caliper. The rubber disk stop will be then placed in tight contact with the soft tissue surface and fixed with a drop of cyanocrylic adhesive. After file removal, the distance between file tip and the silicon stop will be measured using a digital caliper with 0.01 mm of accuracy. (Cairo et al. 2017; Bittner et al. 2020)	T0b: baseline after surgery
Primary	Soft Tissue Thickness (STT)	Measured at 3 and 6 mm from the free gingival margin using a 15-endodontic file and a rubber disk. The file will advance perpendicularly through the soft tissue until the first point of bone contact. Thickness will be measured to the nearest 0.1 mm using a caliper. The rubber disk stop will be then placed in tight contact with the soft tissue surface and fixed with a drop of cyanocrylic adhesive. After file removal, the distance between file tip and the silicon stop will be measured using a digital caliper with 0.01 mm of accuracy. (Cairo et al. 2017; Bittner et al. 2020)	T2: 12 months after implant placement
Secondary	Vertical position of soft tissue (VPS)	A tooth-supported Essix stent will be used to record the distance from three reference marks (mesial papilla, midbuccal margin, and distal papilla) to the free gingival margin using a color-coded probe (15mm, UNC). The same stent will be used for measurements at the different follow-up visits. (Bittner et al. 2020)	T0a: baseline before surgery
Secondary	Vertical position of soft tissue (VPS)	A tooth-supported Essix stent will be used to record the distance from three reference marks (mesial papilla, midbuccal margin, and distal papilla) to the free gingival margin using a color-coded probe (15mm, UNC). The same stent will be used for measurements at the different follow-up visits. (Bittner et al. 2020)	T0b: baseline after surgery
Secondary	Vertical position of soft tissue (VPS)	A tooth-supported Essix stent will be used to record the distance from three reference marks (mesial papilla, midbuccal margin, and distal papilla) to the free gingival margin using a color-coded probe (15mm, UNC). The same stent will be used for measurements at the different follow-up visits. (Bittner et al. 2020)	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Vertical position of soft tissue (VPS)	A tooth-supported Essix stent will be used to record the distance from three reference marks (mesial papilla, midbuccal margin, and distal papilla) to the free gingival margin using a color-coded probe (15mm, UNC). The same stent will be used for measurements at the different follow-up visits. (Bittner et al. 2020)	T2: 12 months after surgery
Secondary	Vertical position of soft tissue (VPS)	A tooth-supported Essix stent will be used to record the distance from three reference marks (mesial papilla, midbuccal margin, and distal papilla) to the free gingival margin using a color-coded probe (15mm, UNC). The same stent will be used for measurements at the different follow-up visits. (Bittner et al. 2020)	T3: 24 months after surgery
Secondary	Vertical position of soft tissue (VPS)	A tooth-supported Essix stent will be used to record the distance from three reference marks (mesial papilla, midbuccal margin, and distal papilla) to the free gingival margin using a color-coded probe (15mm, UNC). The same stent will be used for measurements at the different follow-up visits. (Bittner et al. 2020)	T4: 36 months after surgery
Secondary	Assessment of the linear volumetric changes	Impressions of the grafted sites will be taken including at least the two neighboring teeth and using a silicone impression material. Dental stone casts will be fabricated and optically scanned with a desktop 3D scanner. Digital models of each time-point per patient will be captured as stereolithography (STL) files. The images of the baseline and follow-up datasets will be superimposed and matched using the best-fit algorithm at the adjacent tooth surfaces. After definition of specific regions of interest (ROI), the software will calculated the volumetric changes measured in mm, which will correspond to the mean distance between the three surfaces representing the evaluated time-points. One buccal ROI will be defined: a trapezoid shape area between the gingival margins of the adjacent teeth, the mucogingival junction as apical and the interproximal areas as lateral borders. The measured will be kept constant in each patient and site over time. (Zeltner 2017)	T0a: baseline before surgery
Secondary	Assessment of the linear volumetric changes	Impressions of the grafted sites will be taken including at least the two neighboring teeth and using a silicone impression material. Dental stone casts will be fabricated and optically scanned with a desktop 3D scanner. Digital models of each time-point per patient will be captured as stereolithography (STL) files. The images of the baseline and follow-up datasets will be superimposed and matched using the best-fit algorithm at the adjacent tooth surfaces. After definition of specific regions of interest (ROI), the software will calculated the volumetric changes measured in mm, which will correspond to the mean distance between the three surfaces representing the evaluated time-points. One buccal ROI will be defined: a trapezoid shape area between the gingival margins of the adjacent teeth, the mucogingival junction as apical and the interproximal areas as lateral borders. The measured will be kept constant in each patient and site over time. (Zeltner 2017)	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Assessment of the linear volumetric changes	Impressions of the grafted sites will be taken including at least the two neighboring teeth and using a silicone impression material. Dental stone casts will be fabricated and optically scanned with a desktop 3D scanner. Digital models of each time-point per patient will be captured as stereolithography (STL) files. The images of the baseline and follow-up datasets will be superimposed and matched using the best-fit algorithm at the adjacent tooth surfaces. After definition of specific regions of interest (ROI), the software will calculated the volumetric changes measured in mm, which will correspond to the mean distance between the three surfaces representing the evaluated time-points. One buccal ROI will be defined: a trapezoid shape area between the gingival margins of the adjacent teeth, the mucogingival junction as apical and the interproximal areas as lateral borders. The measured will be kept constant in each patient and site over time. (Zeltner 2017)	T2: 12 months after surgery
Secondary	Assessment of the linear volumetric changes	Impressions of the grafted sites will be taken including at least the two neighboring teeth and using a silicone impression material. Dental stone casts will be fabricated and optically scanned with a desktop 3D scanner. Digital models of each time-point per patient will be captured as stereolithography (STL) files. The images of the baseline and follow-up datasets will be superimposed and matched using the best-fit algorithm at the adjacent tooth surfaces. After definition of specific regions of interest (ROI), the software will calculated the volumetric changes measured in mm, which will correspond to the mean distance between the three surfaces representing the evaluated time-points. One buccal ROI will be defined: a trapezoid shape area between the gingival margins of the adjacent teeth, the mucogingival junction as apical and the interproximal areas as lateral borders. The measured will be kept constant in each patient and site over time. (Zeltner 2017)	T3: 24 months after surgery
Secondary	Assessment of the linear volumetric changes	Impressions of the grafted sites will be taken including at least the two neighboring teeth and using a silicone impression material. Dental stone casts will be fabricated and optically scanned with a desktop 3D scanner. Digital models of each time-point per patient will be captured as stereolithography (STL) files. The images of the baseline and follow-up datasets will be superimposed and matched using the best-fit algorithm at the adjacent tooth surfaces. After definition of specific regions of interest (ROI), the software will calculated the volumetric changes measured in mm, which will correspond to the mean distance between the three surfaces representing the evaluated time-points. One buccal ROI will be defined: a trapezoid shape area between the gingival margins of the adjacent teeth, the mucogingival junction as apical and the interproximal areas as lateral borders. The measured will be kept constant in each patient and site over time. (Zeltner 2017)	T4: 36 months after surgery
Secondary	Pink Esthetic Score (PES)	PES is based on seven variables: mesial papilla, distal papilla, soft-tissue level, soft- tissue contour, alveolar process deficiency, soft-tissue colour and texture. Each variable will be assessed with a 2-1-0 score, with 2 being the best and 0 being the poorest score. The papillae values will be evaluated for completeness, incompleteness or absence. Other variables will be assessed by comparison with a reference tooth. The highest possible score reflecting a perfect match of the peri-implant soft tissue with that of the reference tooth will be 14. (Furhauser et al. 2005)	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Pink Esthetic Score (PES)	PES is based on seven variables: mesial papilla, distal papilla, soft-tissue level, soft- tissue contour, alveolar process deficiency, soft-tissue colour and texture. Each variable will be assessed with a 2-1-0 score, with 2 being the best and 0 being the poorest score. The papillae values will be evaluated for completeness, incompleteness or absence. Other variables will be assessed by comparison with a reference tooth. The highest possible score reflecting a perfect match of the peri-implant soft tissue with that of the reference tooth will be 14. (Furhauser et al. 2005)	T2: 12 months after surgery
Secondary	Pink Esthetic Score (PES)	PES is based on seven variables: mesial papilla, distal papilla, soft-tissue level, soft- tissue contour, alveolar process deficiency, soft-tissue colour and texture. Each variable will be assessed with a 2-1-0 score, with 2 being the best and 0 being the poorest score. The papillae values will be evaluated for completeness, incompleteness or absence. Other variables will be assessed by comparison with a reference tooth. The highest possible score reflecting a perfect match of the peri-implant soft tissue with that of the reference tooth will be 14. (Furhauser et al. 2005)	T3: 24 months after surgery
Secondary	Pink Esthetic Score (PES)	PES is based on seven variables: mesial papilla, distal papilla, soft-tissue level, soft- tissue contour, alveolar process deficiency, soft-tissue colour and texture. Each variable will be assessed with a 2-1-0 score, with 2 being the best and 0 being the poorest score. The papillae values will be evaluated for completeness, incompleteness or absence. Other variables will be assessed by comparison with a reference tooth. The highest possible score reflecting a perfect match of the peri-implant soft tissue with that of the reference tooth will be 14. (Furhauser et al. 2005)	T4: 36 months after surgery
Secondary	Papillae index (PI)	The statuses of the mesial and distal papilla will be assessed using the Papillae index (from 0 to 3). (Jemt et al. 1997)	T0a: baseline before surgery
Secondary	Papillae index (PI)	The statuses of the mesial and distal papilla will be assessed using the Papillae index (from 0 to 3). (Jemt et al. 1997)	T0b: baseline after surgery
Secondary	Papillae index (PI)	The statuses of the mesial and distal papilla will be assessed using the Papillae index (from 0 to 3). (Jemt et al. 1997)	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Papillae index (PI)	The statuses of the mesial and distal papilla will be assessed using the Papillae index (from 0 to 3). (Jemt et al. 1997)	T2: 12 months after surgery
Secondary	Papillae index (PI)	The statuses of the mesial and distal papilla will be assessed using the Papillae index (from 0 to 3). (Jemt et al. 1997)	T3: 24 months after surgery
Secondary	Papillae index (PI)	The statuses of the mesial and distal papilla will be assessed using the Papillae index (from 0 to 3). (Jemt et al. 1997)	T4: 36 months after surgery
Secondary	Width of keratinized tissue (WKT)	WKT will be measured, with a periodontal probe (mm), mid-facially from the gingival margin to the muco-gingival junction of the intended extracted tooth or the implant supported restoration.	T0a: baseline before surgery
Secondary	Width of keratinized tissue (WKT)	WKT will be measured, with a periodontal probe (mm), mid-facially from the gingival margin to the muco-gingival junction of the intended extracted tooth or the implant supported restoration.	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Width of keratinized tissue (WKT)	WKT will be measured, with a periodontal probe (mm), mid-facially from the gingival margin to the muco-gingival junction of the intended extracted tooth or the implant supported restoration.	T2: 12 months after surgery
Secondary	Width of keratinized tissue (WKT)	WKT will be measured, with a periodontal probe (mm), mid-facially from the gingival margin to the muco-gingival junction of the intended extracted tooth or the implant supported restoration.	T3: 24 months after surgery
Secondary	Width of keratinized tissue (WKT)	WKT will be measured, with a periodontal probe (mm), mid-facially from the gingival margin to the muco-gingival junction of the intended extracted tooth or the implant supported restoration.	T4: 36 months after surgery
Secondary	Peri-implant marginal bone level (MBL)	MBL will be measured on intraoral radiographs at the mesial and distal aspects (m and d). It will be set as the distance between the reference point and the most apical point of contact between the implant surface and the bone. The reference point will be the fixture-abutment interface. Digital intraoral periapical radiographs will be taken using a parallel cone technique with digital sensor. A paralleling device and individualized bite blocks made of polyvinyl siloxane impression material will be used for the standardization of the X-ray geometry. Calibration will be performed using the known thread-pitch distance of the implants. Measurements will be taken to the nearest millimeter using computer software.	T0b: baseline after surgery
Secondary	Peri-implant marginal bone level (MBL)	MBL will be measured on intraoral radiographs at the mesial and distal aspects (m and d). It will be set as the distance between the reference point and the most apical point of contact between the implant surface and the bone. The reference point will be the fixture-abutment interface. Digital intraoral periapical radiographs will be taken using a parallel cone technique with digital sensor. A paralleling device and individualized bite blocks made of polyvinyl siloxane impression material will be used for the standardization of the X-ray geometry. Calibration will be performed using the known thread-pitch distance of the implants. Measurements will be taken to the nearest millimeter using computer software.	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Peri-implant marginal bone level (MBL)	MBL will be measured on intraoral radiographs at the mesial and distal aspects (m and d). It will be set as the distance between the reference point and the most apical point of contact between the implant surface and the bone. The reference point will be the fixture-abutment interface. Digital intraoral periapical radiographs will be taken using a parallel cone technique with digital sensor. A paralleling device and individualized bite blocks made of polyvinyl siloxane impression material will be used for the standardization of the X-ray geometry. Calibration will be performed using the known thread-pitch distance of the implants. Measurements will be taken to the nearest millimeter using computer software.	T2: 12 months after surgery
Secondary	Peri-implant marginal bone level (MBL)	MBL will be measured on intraoral radiographs at the mesial and distal aspects (m and d). It will be set as the distance between the reference point and the most apical point of contact between the implant surface and the bone. The reference point will be the fixture-abutment interface. Digital intraoral periapical radiographs will be taken using a parallel cone technique with digital sensor. A paralleling device and individualized bite blocks made of polyvinyl siloxane impression material will be used for the standardization of the X-ray geometry. Calibration will be performed using the known thread-pitch distance of the implants. Measurements will be taken to the nearest millimeter using computer software.	T3: 24 months after surgery
Secondary	Peri-implant marginal bone level (MBL)	MBL will be measured on intraoral radiographs at the mesial and distal aspects (m and d). It will be set as the distance between the reference point and the most apical point of contact between the implant surface and the bone. The reference point will be the fixture-abutment interface. Digital intraoral periapical radiographs will be taken using a parallel cone technique with digital sensor. A paralleling device and individualized bite blocks made of polyvinyl siloxane impression material will be used for the standardization of the X-ray geometry. Calibration will be performed using the known thread-pitch distance of the implants. Measurements will be taken to the nearest millimeter using computer software.	T4: 36 months after surgery
Secondary	Phenotype	It will be based on the lack of transparency of a periodontal probe through the gingival margin when probing the buccal sulcus of the failing tooth (De Rouck et al. 2009).	T0a: baseline before surgery
Secondary	Phenotype	It will be based on the lack of transparency of a periodontal probe through the gingival margin when probing the buccal sulcus of the failing tooth (De Rouck et al. 2009).	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Phenotype	It will be based on the lack of transparency of a periodontal probe through the gingival margin when probing the buccal sulcus of the failing tooth (De Rouck et al. 2009).	T2: 12 months after surgery
Secondary	Phenotype	It will be based on the lack of transparency of a periodontal probe through the gingival margin when probing the buccal sulcus of the failing tooth (De Rouck et al. 2009).	T3: 24 months after surgery
Secondary	Phenotype	It will be based on the lack of transparency of a periodontal probe through the gingival margin when probing the buccal sulcus of the failing tooth (De Rouck et al. 2009).	T4: 36 months after surgery
Secondary	Probing pocket depth (PD)	probing pocket depth using a manual periodontal probe at the mesio-buccal, mid-buccal, and disto-buccal and mid-palatal aspect. The distance measured from the base of the pocket to the most apical point on the gingival margin, expressed in millimeters (Mombelli et al., 1987).	T0a: baseline before surgery
Secondary	Probing pocket depth (PD)	probing pocket depth using a manual periodontal probe at the mesio-buccal, mid-buccal, and disto-buccal and mid-palatal aspect.The distance measured from the base of the pocket to the most apical point on the gingival margin, expressed in millimeters (Mombelli et al., 1987).	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Probing pocket depth (PD)	probing pocket depth using a manual periodontal probe at the mesio-buccal, mid-buccal, and disto-buccal and mid-palatal aspect.The distance measured from the base of the pocket to the most apical point on the gingival margin, expressed in millimeters (Mombelli et al., 1987).	T2: 12 months after surgery
Secondary	Probing pocket depth (PD)	probing pocket depth using a manual periodontal probe at the mesio-buccal, mid-buccal, and disto-buccal and mid-palatal aspect.The distance measured from the base of the pocket to the most apical point on the gingival margin, expressed in millimeters (Mombelli et al., 1987).	T3: 24 months after surgery
Secondary	Probing pocket depth (PD)	probing pocket depth using a manual periodontal probe at the mesio-buccal, mid-buccal, and disto-buccal and mid-palatal aspect.The distance measured from the base of the pocket to the most apical point on the gingival margin, expressed in millimeters (Mombelli et al., 1987).	T4: 36 months after surgery
Secondary	Modified Plaque Index (mPI)	Modified Plaque Index (mPI) is a dental plaque scale as follows 0 = No plaque,; 1 = Separate flecks of plaque at the cervical margin;2 = Plaque can be seen by naked eye.3 = Abundance of soft matter. The lower the number the less plaque is present on the tooth. (Mombelli et al., 1987);	T0a: baseline before surgery
Secondary	Modified Plaque Index (mPI)	Modified Plaque Index (mPI) is a dental plaque scale as follows 0 = No plaque,; 1 = Separate flecks of plaque at the cervical margin;2 = Plaque can be seen by naked eye.3 = Abundance of soft matter. The lower the number the less plaque is present on the tooth. (Mombelli et al., 1987);	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Modified Plaque Index (mPI)	Modified Plaque Index (mPI) is a dental plaque scale as follows 0 = No plaque,; 1 = Separate flecks of plaque at the cervical margin;2 = Plaque can be seen by naked eye.3 = Abundance of soft matter. The lower the number the less plaque is present on the tooth. (Mombelli et al., 1987);	T2: 12 months after surgery
Secondary	Modified Plaque Index (mPI)	Modified Plaque Index (mPI) is a dental plaque scale as follows 0 = No plaque,; 1 = Separate flecks of plaque at the cervical margin;2 = Plaque can be seen by naked eye.3 = Abundance of soft matter. The lower the number the less plaque is present on the tooth. (Mombelli et al., 1987);	T3: 24 months after surgery
Secondary	Modified Plaque Index (mPI)	Modified Plaque Index (mPI) is a dental plaque scale as follows 0 = No plaque,; 1 = Separate flecks of plaque at the cervical margin;2 = Plaque can be seen by naked eye.3 = Abundance of soft matter. The lower the number the less plaque is present on the tooth. (Mombelli et al., 1987);	T4: 36 months after surgery
Secondary	Gingival bleeding on probing (BoP)	Gingival bleeding on probing (BOP) using the modified sulcus bleeding index for implants. Scale equals 0 = No bleeding when periodontal probe is passed along the gingival margin;1 = Isolated bleeding spots visible;2 = Blood forms a confluent red line on the gingival margin;3 = Heavy or profuse bleeding. (Mombelli et al., 1987).	T0a: baseline before surgery
Secondary	Gingival bleeding on probing (BoP)	Gingival bleeding on probing (BOP) using the modified sulcus bleeding index for implants. Scale equals 0 = No bleeding when periodontal probe is passed along the gingival margin;1 = Isolated bleeding spots visible;2 = Blood forms a confluent red line on the gingival margin;3 = Heavy or profuse bleeding. (Mombelli et al., 1987).	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Gingival bleeding on probing (BoP)	Gingival bleeding on probing (BOP) using the modified sulcus bleeding index for implants. Scale equals 0 = No bleeding when periodontal probe is passed along the gingival margin;1 = Isolated bleeding spots visible;2 = Blood forms a confluent red line on the gingival margin;3 = Heavy or profuse bleeding. (Mombelli et al., 1987).	T2: 12 months after surgery
Secondary	Gingival bleeding on probing (BoP)	Gingival bleeding on probing (BOP) using the modified sulcus bleeding index for implants. Scale equals 0 = No bleeding when periodontal probe is passed along the gingival margin;1 = Isolated bleeding spots visible;2 = Blood forms a confluent red line on the gingival margin;3 = Heavy or profuse bleeding. (Mombelli et al., 1987).	T3: 24 months after surgery
Secondary	Gingival bleeding on probing (BoP)	Gingival bleeding on probing (BOP) using the modified sulcus bleeding index for implants. Scale equals 0 = No bleeding when periodontal probe is passed along the gingival margin;1 = Isolated bleeding spots visible;2 = Blood forms a confluent red line on the gingival margin;3 = Heavy or profuse bleeding. (Mombelli et al., 1987).	T4: 36 months after surgery
Secondary	Implant success	Implant failure and Implant success criteria will be recorded according to Buser et al.1990.	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Implant success	Implant failure and Implant success criteria will be recorded according to Buser et al.1990.	T2: 12 months after surgery
Secondary	Implant success	Implant failure and Implant success criteria will be recorded according to Buser et al.1990.	T3: 24 months after surgery
Secondary	Implant success	Implant failure and Implant success criteria will be recorded according to Buser et al.1990.	T4: 36 months after surgery
Secondary	Biological and technical complication	Complications from biological and technical nature (Pjetursson et al. 2012).	T0a: baseline before surgery
Secondary	Biological and technical complication	Complications from biological and technical nature (Pjetursson et al. 2012).	T0b: baseline after surgery
Secondary	Biological and technical complication	Complications from biological and technical nature (Pjetursson et al. 2012).	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Biological and technical complication	Complications from biological and technical nature (Pjetursson et al. 2012).	T2: 12 months after surgery
Secondary	Biological and technical complication	Complications from biological and technical nature (Pjetursson et al. 2012).	T3: 24 months after surgery
Secondary	Biological and technical complication	Complications from biological and technical nature (Pjetursson et al. 2012).	T4: 36 months after surgery
Secondary	Surgery time	The surgery time will be recorded in both groups to the closest minute from the start of the first incision to the accomplishment of the last suture.	T0a-b: baseline
Secondary	Patient satisfaction OHIP-14	The Oral Health Impact Profile (OHIP-14) is a questionnaire addressed the following domains: functional limitation, physical pain, psychological discomfort, physical disability, psycho- logical disability, social disability and handicap. These domains were evaluated by 2 questions each and scored by means of a 5-point Likert scale resulting in a total OHIP score ranging from 14 to 70 with higher scores being indicative of more discomfort in daily life. (Slade & Spencer, 1994)	T0a: baseline before surgery
Secondary	Patient satisfaction OHIP-14	The Oral Health Impact Profile (OHIP-14) is a questionnaire addressed the following domains: functional limitation, physical pain, psychological discomfort, physical disability, psycho- logical disability, social disability and handicap. These domains were evaluated by 2 questions each and scored by means of a 5-point Likert scale resulting in a total OHIP score ranging from 14 to 70 with higher scores being indicative of more discomfort in daily life. (Slade & Spencer, 1994)	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Patient satisfaction OHIP-14	The Oral Health Impact Profile (OHIP-14) is a questionnaire addressed the following domains: functional limitation, physical pain, psychological discomfort, physical disability, psycho- logical disability, social disability and handicap. These domains were evaluated by 2 questions each and scored by means of a 5-point Likert scale resulting in a total OHIP score ranging from 14 to 70 with higher scores being indicative of more discomfort in daily life. (Slade & Spencer, 1994)	T2: 12 months after surgery
Secondary	Patient satisfaction OHIP-14	The Oral Health Impact Profile (OHIP-14) is a questionnaire addressed the following domains: functional limitation, physical pain, psychological discomfort, physical disability, psycho- logical disability, social disability and handicap. These domains were evaluated by 2 questions each and scored by means of a 5-point Likert scale resulting in a total OHIP score ranging from 14 to 70 with higher scores being indicative of more discomfort in daily life. (Slade & Spencer, 1994)	T3: 24 months after surgery
Secondary	Patient satisfaction OHIP-14	The Oral Health Impact Profile (OHIP-14) is a questionnaire addressed the following domains: functional limitation, physical pain, psychological discomfort, physical disability, psycho- logical disability, social disability and handicap. These domains were evaluated by 2 questions each and scored by means of a 5-point Likert scale resulting in a total OHIP score ranging from 14 to 70 with higher scores being indicative of more discomfort in daily life. (Slade & Spencer, 1994)	T4: 36 months after surgery
Secondary	Patient satisfaction VAS	Patients were asked to respond to the following question on a Visual analogic scale: "How satisfied are you with the overall aesthetic result?" and "How satisfied are you with the overall functional result?"."Most unsatisfied" and "most satisfied" were indicated as extremes on the 100-mm lines.	T0a: baseline before surgery
Secondary	Patient satisfaction VAS	Patients were asked to respond to the following question on a Visual analogic scale: "How satisfied are you with the overall aesthetic result?" and "How satisfied are you with the overall functional result?"."Most unsatisfied" and "most satisfied" were indicated as extremes on the 100-mm lines.	T1: 2 weeks after crown delivery, 4 months from surgery
Secondary	Patient satisfaction VAS	Patients were asked to respond to the following question on a Visual analogic scale: "How satisfied are you with the overall aesthetic result?" and "How satisfied are you with the overall functional result?"."Most unsatisfied" and "most satisfied" were indicated as extremes on the 100-mm lines.	T2: 12 months after surgery
Secondary	Patient satisfaction VAS	Patients were asked to respond to the following question on a Visual analogic scale: "How satisfied are you with the overall aesthetic result?" and "How satisfied are you with the overall functional result?"."Most unsatisfied" and "most satisfied" were indicated as extremes on the 100-mm lines.	T3: 24 months after surgery
Secondary	Patient satisfaction VAS	Patients were asked to respond to the following question on a Visual analogic scale: "How satisfied are you with the overall aesthetic result?" and "How satisfied are you with the overall functional result?"."Most unsatisfied" and "most satisfied" were indicated as extremes on the 100-mm lines.	T4: 36 months after surgery