1. Histological Evaluation Comparing Alloplast and Xenograft in Socket Preservation- A Case Series Lanka Mahesh, BDS, MS (Implant Dentistry), Srinivas A. Katta, BDS MS* Diplomate, ICOI (USA)- Private Practice, New Delhi, India *NovaBone Products LLC, Alachua FL 32615
Objective
Tooth extraction becomes mandatory when all efforts to preserve the tooth fail. Normal healing response after extraction results in bone loss and ridge resorption. The degree of ridge resorption greatly increases with the time elapsed since tooth extraction with the greatest occurring in the immediate post-extraction period1. It becomes essential to regenerate bone in the extraction socket to prevent ridge resorption and provide a stable base for implant placement. There are several techniques available to regenerate socket bone. Bio-col socket preservation technique utilizing Bio-Oss (Osteohealth, Shirley, NY, USA) and CollaPlug (Zimmer Dental, Carlsbad, CA) suggested by Sclar2 remains least invasive and effective.
The aim of this study was to histologically evaluate and compare bone regeneration in 20 extraction sockets using an Alloplast - Calcium phosphosilicate putty (CPS Putty) (NovaBone Dental Putty, Alachua, FL, USA) and anorganic bovine xenograft (Bio-Oss).
Histomorphometric data presented in Tables 1 & 2 indicate that the xenograft showed a range of residual bone graft (RBG) from a maximum of 38% at 4 months and a minimum of 18% at 6 months with an average of 25.7%. The CPS Putty group showed a range of RBG from 30% at 4 months and a minimum of 3% at 6 months with an average of 17.4%. Table 3 summarizes the differences in residual graft between both groups at 4 and 6 months. At 6 months the Amount of new bone regenerated was also higher in the alloplast group (Avg.45.2%) as compared to the xenograft group (Avg. 25.8%).
Fig 2: Regenerated socket at 4 months using CPS Putty (A) and at 6 months using Xenograft (B)
Histomorphometry
Histology sections from both groups (Fig 3) showed the presence of vital, healthy trabecular and woven bone and bone marrow with evidence of remodeling, indicated by resting and reversal lines with variable quantities of residual bone graft material. These sections were then analyzed at 10x magnification using Motic plus 2ML image analysis software.
Fig 1: Placement of CPS Putty (A) and Xenograft particulate (B) in sockets
Table 3: Comparison of % RBG in the two groups at 4 and 6 months and % new bone at 6 months
Methods
Twenty patients underwent atraumatic tooth extractions following a specific protocol. After extraction the patients were randomized to receive either the alloplast or xenograft (Fig. 1) (Tables 1&2), a collagen plug was placed to cover the socket and the socket was stabilized with mattress sutures. Patients were recalled after 4-6 months to evaluate the bone regeneration prior to implant placement. A 3.0mm inner diameter trephine bur was used to obtain the core from the center of the regenerated area. The core was preserved in 10% formalin and sent for histopathological evaluation.
Results show that there was a significant reduction in residual graft volume in CPS Putty cases when compared with Xenograft cases at the end of 6 months. However at the end of 4 months, the difference in RBG between the groups is statistically insignificant.
Fig 2: Histology Sections A) CPS Putty B) Xenograft taken at 4 and 6 months respectively
Tooth #
Time
(Months)
Residual
Bone 14 6 3% 35 4
24% 11
18% 21
26% 24
13% 25 8%
28%
30% 44
16%
Tooth #
Time
(Months)
Residual
Bone 45 4
38% 23 6
26% 13
24% 11
20% 35 5 33
22% 44
32% 15
28% 24
18% 25
23%
Conclusion
The results of our study showed that both tested materials are clinically viable materials for socket grafting following extraction. CPS Putty seems to show a higher rate of resorption at the end of a 6 month period than xenograft suggesting that alloplast putty demonstrates better graft resorption and bone regeneration values compared with xenograft when used in the bio-col technique. More studies are suggested to confirm the findings.
Results
Clinically and radiographically, all sockets healed without any complications or adverse reactions. No signs of infection or inflammatory response were observed during the healing period. At the time of re-entry, all sockets appeared to be filled with a hard tissue (Fig. 2), which was resistant to penetration by a probe and seemed to be well attached to the walls of the socket. Cores for histomorphometric analysis were taken and Implants were placed in all the sites.
References
Lam RV. Contour changes of the alveolar processes following extrac­tions. J Prosthet Dent 1960; 10:25–32.
Sclar AG. Preserving alveolar ridge anatomy following tooth removal in conjunction with immediate implant placement. The Bio-Col technique. Atlas Oral Maxillofac Surg Clin North Am.1999;7:39-59.
Table 1: CPS Putty Cases
Table 2: Xenograft Cases
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