Evaluation of a Synthetic Bone Substitute Associated With Absorbable Collagen Membrane for Ridge Preservation After Tooth Extraction. Clinical and Tomographic Randomized Study in Humans.

Pre-surgical procedures Before surgical procedures, all patient received oral hygiene instructions, as well as supra and subgingival root planing procedures, in order to control periodontal infections and acute inflammatory processes that could interfere with the wound healing of the sockets. Surgical procedures were performed only after the plaque index reached levels below 20%.

Surgical procedures The patients received local anesthesia (mepivacaine hydrochloride 20 mg / ml epinephrine + 0.01 mg / ml), and afther that the teeth were carefully extracted using a periotome (Hu-friedy instruments, Chicago, IL, USA). Then, vertical releasing incisions were performed in the distal faces teeths adjacent to the socket with a 15C scalpel blade, and connected by intrasulcular incisions (Figure 1b). After that, a full thickness flap was raised (Figure 1c). Granulation tissue was removed, and then clinical measurements in both selected sockets were made: Clinical Buccal Alveolar Measure (CBAM) - distance between the bottom of the socket and the buccal bone crest (Figure 1d); Clinical Palatal Alveolar Measure (CPAM) - distance between the bottom of the socket and the palatal bone crest; and Clinical Horizontal Alveolar Measure (CHAM) - distance between the buccal and palatal bone crests (Figure 1e).

Following that, in the Control Group (CG) the alveolus was filled with blood clot, while in the Test Group (TG) the alveolus was filled with a bone substitute ReproBone (Ceramisys Ltd., Sheffield,UK), (Fig. 1f). The choose between control and test sockets was randomized by a computer program (SPSS Inc., Chicago, IL, USA). The allocation of each treatment was stored in opaque envelope until immediately before the socket filling procedure.

After that, in both groups, the sockets were covered with a resorbable collagen membrane (BioMend, Zimmer Dental Inc., Carlsbad, CA, USA), which was fixed to the buccal bone plate with a titanium tack (2 mm apically to the socket bottom), which also served as a reference for tomographic measurements (Figure 1g). Then, the membrane was sutured to the lingual flap with 5-0 absorbable suture (B.Braun, Aesculap, Tuttilingen, Germany), and the flap was coronally positioned in order to cover completely the membrane (when necessary, the basis of the flap was carefully dissected to release the flap), and sutured with 4-0 silk sutures (Ethicon, Johnson & Johnson, São Paulo, Brazil), (Figure 1h). All the surgical procedures were performed by the same experimented surgeon.

Post surgical procedures All patients received systemic antibiotics (amoxycillin 500 mg, 3x day) starting 24 hours before the surgical procedure and extending for 10 days after surgery. A non-steroidal antiinflammatory drug (Nimesulide 100mg) was also prescribed, twice a day, for 5 days, as well as analgesic (750 mg paracetamol of 8/8 hours, for 3 days). A 0.12% chlorhexidine digluconate solution was prescribed as mouth rinse to be used twice a day for fifteen days. The patients were instructed to discontinue tooth brushing in the surgical area during this period. Ten days after surgery, silk sutures were removed.