Discussion
This report presented a clinical approach for application of local
pharmaceutical agents together with standard biomaterials for guided
tissue and bone regeneration. Although natural teeth may be extracted
for many reasons, Osaghae and Azodo21 reported that
tooth splitting was the etiological factor for 5% of the extracted
posterior teeth, of which 10% were mandibular first molars. The
prognosis of split teeth with a fracture line extending deep in the
sub-gingival area is usually poor22; therefore, the
teeth in question require replacement with implant or tooth-supported
prosthesis.
A meta-analysis23 reported no difference in success
rates between immediate implant placement in infected and non-infected
extraction sockets. However, such treatment options are contraindicated
in cases with purulent socket infection and poor bone configuration
following extraction.24 Accordingly, a more careful
approach involving proper implant site preparation prior to placement is
feasible to render favorable implant positioning and angulation as
described here.
Management of post-extraction sockets is variable. Introduction of
hemostatic collagen sponges caused delays in the healing process of the
extraction sockets and suppressed differentiation of bone-forming
cells.25 As a variant of the bone graft form used
here, sticky bone resulted in better soft- and hard-tissue healing and
regeneration when used for socket grafting following third-molar
extraction in a split-mouth clinical study.26 Several
biological agents have been reported to supplement the standard
biomaterials in expediting healing and improving postoperative results
following guided tissue and bone-regeneration
procedures.27 Compared with a collagen-sponge group,
supplemental use of recombinant human bone morphogenetic protein 2 with
bone graft material resulted in superior bone gain on the distal
surfaces of second mandibular molars following third molar
extraction.28 A recently published systematic review
and meta-analysis supported the use of platelet-rich fibrin following
extraction and reported a faster wound-healing rate and lesser
postoperative complications.29 The application of
readily available agents such as pre-medicated collagen sponges may
present a convenient strategic option to supplement readily successful
biomaterials for regenerative therapies.
A randomized double-blinded clinical trial30 found
that repeated application of chlorhexidine-containing chips is
beneficial to control sites with active periodontal disease. Local
application of controlled-release chlorhexidine chips improved the
quantity of bone gain upon tissue-regenerative procedures, and infection
control may be crucial for the success of such treatment
interventions.19 Additionally, evaluation of
metronidazole-gel application for tissue regeneration showed that local
application of metronidazole gel yielded successful clinical outcomes in
treating vertical bony-defect cases along with other biomaterials used
for guided tissue regeneration.20 However, no study
has outlined the effects of combined application of these agents in
tissue and bone-regeneration procedures. This report utilized a
pre-medicated collagen sponge containing both active agents in a
scaffold form, facilitating convenient manipulation and adaptation
during the surgical procedure and ensuring local release of these agents
during the healing process of tissue and bone regeneration.