Evaluation of a Synthetic Bone Substitute for Ridge Preservation
Condition: Alveolar Process
Study type: Interventional
Phase: Phase 4

Summary: 
      Fifteen patients were selected, each presenting at least two jaw front teeth indicated for
      extraction: in the Test Group (TG), post-extraction sockets was filled by synthetic bone
      substitute ReproBone, and in the Control Group (CG) the socket was filled only by clot. In
      both groups, the sockets were covered by a resorbable collagen membrane BioMend, which in
      turn was covered by a flap. Computed tomography scans were acquired in the immediate
      postoperative period and 6 months after surgery, and the horizontal and vertical dimensional
      changes in bone crests were quantified.
    

Detailed description: 
      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.

      A week after tooth extraction, a provisory fixed prosthesis was installed, using acrylic
      teeth or the crowns of the extracted teeth. Thirty days after surgery, the molding was
      carried out to fabricate a temporary partial denture, which was installed in all patients
      around 45 days after the GBR procedure; special care was taken to avoid masticatory load in
      the grafted area. The patients were recalled for biofilm control and reinforcement of oral
      hygiene instructions every 7 days in the first two months and then monthly until six months
      after surgery. Six months after regenerative procedure, the patients that manifested interest
      in oral rehabilitation with implants were referred to this service in the University.

      Computerized tomographic analysis One week after surgery a Cone Bean tomography was taken (T1
      - baseline) using a plastic photographic retractor (Januario et al. 2008). A single blinded
      calibrated (Kappa test > 80%) examiner evaluated the foolowing tomographic parameters:
      Tomographic Buccal Alveolar Measure (TBAM), distance between the tack and buccal alveolar
      crest (Figure 2); Tomographic Palatal Alveolar Measure (TPAM), distance between the tack and
      palatal bone crest (Figure 2); Tomographic Horizontal Apical Measure (THAM), distance between
      buccal and palatal bone plates, at tack level; Tomographic Horizontal Cervical Measure
      (THCM), distance between buccal and palatal bone plates, at crestal level (Figure 2);
      Tomographic Alveolar Height Measure (TAHM), distance between a line defined by the buccal and
      palatal bone crests and the THAM line (Figure 3).

      After 6 months, a second Cone Bean tomography was taken (T2 - 6 months postoperative) as
      described previously. The same measures were obtained on T2 tomography in order to evaluate
      the dimensional changes in the period. Computerized tomography exams were acquired by a
      scanner model iCat Classic (Imaging Sciences International, LCC, Hatfield, PA, USA), 0.25 mm
      slice thickness, 0.25 mm reconstruction interval, and exposure factors of 120 KV and 36.12
      mAs. Data were stored in DICOM format, and analyzed using the Ez3D Plus software.
    

Intervention name(s): BioMend and ReproBone; BioMend without ReproBone
Intervention type(s): Drug; Drug
Intervention description(s): Post-extraction sockets was filled by synthetic bone substitute ReproBone, and after the sockets were covered by a resorbable collagen membrane BioMend, which in turn was covered by a flap.; Post-extraction the socket was filled only by clot and covered by a resorbable collagen membrane BioMend, which in turn was covered by a flap.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Alveolar ridge; guided bone regeneration; bone grafts