Histomorphometric Evaluation of Ridge Preservation With and Without Connective Tissue Graft Over Buccal Plate Using Different Types of Bone Substitute: An Animal Study Gerardo Mendoza-Azpur, DDS, MSc,* Allinson Olaechea, DDS,† Marialuisa Pinazo, DDS,† Cesar Gomez, DDS,† Elmer Salinas, DDS,‡ Manuel de la rosa, DDS, MSc,§ and Ismael Khouly, DDS, MS, PhD¶k T ooth extraction is one of the most widely performed dental procedures. Dimensional ch- anges in hard and soft tissue are ex- pected to occur during healing after tooth extraction. 1–5 Multiple preclini- cal and clinical studies have reported that normal healing after tooth extrac- tion involves reduction in the height and width of the alveolar ridge, which is usually more marked on ridge width than in height. 2–6 The resorption of the buccal plate is normally greater than that of lingual or palatal bone. 3 The magnitude of these dimensional changes is important for comprehen- sive treatment planning and to decrease future prosthetic complica- tions or esthetic problems. 7 Hence, the alveolar ridge preserva- tion (RP) concept was proposed to prevent or minimize the postextraction bone resorption and preserve the alve- olar ridge by means of bone graft materials filling the socket immediately after extraction. 7–9 Several studies have demonstrated the positive effect of using different types of bone graft ma- terials, including autograft, 10 allo- graft, 11 xenograft, 12 and alloplast, 10 as well as nonresorbable and resorbable membranes. 13 However, current evi- dence has reported limitations in this technique, indicating that bone resorp- tion is not completely preventable, regardless of the grafting material applied. To reduce some of these limi- tations and improve the outcomes of conventional RP, a new modified approach was introduced, consisting of overbuilding the buccal plate using *Chairman, Department of Periodontology, School of Dentistry, Cientifica del Sur University, Lima, Peru. †Resident, Department of Implantology, School of Dentistry, Cientifica del Sur University, Lima, Peru. ‡Head of Implant, Department of Periodontology, School of Dentistry, Cientifica del Sur University, Lima, Peru. §Professor, Department of Periodontology, University of Monterrey, Monterrey, Mexico. ¶Clinical Assistant Professor, Department of Oral & Maxillofacial Surgery, New York University College of Dentistry, New York, NY. kClinical Investigator, Bluestone Center for Clinical Research, New York University College of Dentistry, New York, NY. Reprint requests and correspondence to: Gerardo Mendoza-Azpur, DDS, MSc, Department of Periodontology, School of Dentistry, Cientifica del Sur University, Calle Enrique Palacios 861, Dep 302, Miraflores, Lima, 18 Peru, E-mail: gmendoza@ cientifica.edu.pe ISSN 1056-6163/15/02406-686 Implant Dentistry Volume 24  Number 6 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/ID.0000000000000307 Purpose: The aim of this inves- tigation was to assess the efficacy of using subepithelial connective tissue graft (CTG) over the buccal plate in conjunction with 2 different bone graft materials in fresh extraction sites. Materials and Methods: Five mongrel dogs were used. Bilateral third (P3) mandibular premolars were extracted atraumatically. An- imals were randomly divided in the 4 experimental groups: no CT (NCT) + anorganic bovine bone (ABB), NCT + biphasic calcium phosphate (BCP), CT + ABB, and CT + BCP. This study evaluated tissue healing at 15, 30, 60, 90, and 120 days after socket preserva- tion, using histologic and histomor- phometric analyses. Results: The main finding showed that all groups presented similar results with minor differen- ces regardless of the use of CTG and type of bone substitute. A greater amount of residual graft particles was found when ABB was used. No differences in the histologic and histomorphometric analysis were found when comparing the use of CTG with NCTG for ridge preserva- tion procedure. Conclusion: Within the limita- tions of this animal study, the use of CTG to overbuild the buccal plate at time of tooth extraction did not affect the quality of bone regeneration. (Implant Dent 2015;24:686–692) Key Words: socket grafting, soft tis- sue graft, bone graft, tooth extrac- tion, histological analysis 686 HISTOMORPHOMETRIC EVALUATION OF RIDGE PRESERVATION MENDOZA-AZPUR ET AL Copyright © 201 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. 5