Quality Resource Guide

Alveolar Ridge Preservation Following Tooth Extraction 3rd Edition

www.metdental.com

Within the same lines, recent systematic reviews

(Darby

et al.

2009 and Vignoletti

et al

. 2012,

Avila-ortiz 2019) indicated that ridge preservation

procedures are effective in limiting horizontal and

vertical dimensional changes in post-extraction sites.

The meta-analyses performed by Avila-Ortiz

et al. indicated that ridge preservation resulted

in significantly less horizontal and vertical

contraction as compared to extraction alone.

The weighted mean difference showed that ridge

preservation

prevented an additional

horizontal

resorption of 1.99 mm (95% CI 1.54 to 2.44,

P < 0.00001), vertical mid-buccal resorption of

1.72 mm (95% CI 0.96 to 2.48; P < 0.00001)

and

vertical mid-lingual resorption of 1.16 mm

(95% CI 0.81 to 1.52; P < 0.00001) compared to

extraction alone.

Materials

Materials including bone grafts and membranes

used for ridge preservation are similar to the

ones used for guided bone regeneration (GBR) or

guided tissue regeneration (GTR) procedures. Most

commonly used bone grafts included allografts

(Freeze-dried bone allograft (FDBA), demineralized

freeze-dried bone allograft (DFDBA)), deproteinized

bovine bone mineral and autogenous bone. Some

studies also reported on the use of alloplastic

materials, e.g. bio-glass, hydroxyapatite, calcium

sulfate. The most commonly used membranes

include

resorbable

collagen,

non-resorbable

expanded

polytetrafluoroethylene

(ePTFE)

dense polytetrafluoroethylene (dPTFE), polylactid/

polyglycolic membranes and acellular dermal matrix

grafts. Some studies have also successfully used

collagen wound dressing materials (e.g. CollaPlug®,

CollaTape®) which resorb faster than the previously

mentioned resorbable membranes (For review see

Darby et al. 2009).

Most randomized controlled clinical trials have

compared ridge preservation to no intervention

(

i.e.

no socket filling) and have demonstrated the

benefit of ridge preservation over no intervention.

In contrast there are fewer clinical trials which have

reported on the outcomes on different grafting

materials in a side by side comparison. A series

of studies have looked at the advantages and

disadvantages of specific grafting materials, they are

presented below:

FDBA vs. DFDBA:

Allografts combine the advantage of unrestricted

availability and the avoidance of a second surgical

site for graft procurement thereby decreasing

patient morbidity. FDBA and DFDBA differ in their

processing resulting into respective advantageous

properties. FDBA with a higher mineral content

was suggested to act as a better space maintaining

osteoconductive scaffold than DFDBA (Piatelli

et al

. 1996). Conversely, the demineralization

process allow the release of bone morphogenetic

proteins from DFDBA responsible for its unique

osteoinductive property, potentially improving vital

bone formation (Urist and Strates 1971).

Wood & Mealey (2012) performed ridge preservation

in 40 patients which were randomized to receive

either FDBA or DFDBA as a grafting material

following extraction of non-molar teeth. The sites

were subsequently covered with a resorbable

collagen membrane and allowed to heal for 18

to 20 weeks before bone cores were trephined

out at the prospective implant site and submitted

for histomorphometric analyses. Moreover, clinical

dimensions of the ridge were recorded at the time of

extraction and 18 to 20 weeks thereafter.

No differences were found between FDBA and

DFDBA in the amount of ridge dimension alterations

at time of implant placement. Conversely, the

histomorphometric analyses showed that sites

grafted with DFDBA resulted in significant more vital

bone, consistent with its osteoinductive property, and

less residual graft particles. Therefore, the clinician

may prefer to use DFDBA over FDBA for ridge

preservation purposes in order to obtain more vital

bone at 18 to 20 weeks after grafting.

One of the disadvantages of DFDBA is that

radiographically, due to the demineralized nature of

the graft, the preserved site may not be readily seen

on a radiograph unless a long enough time period

has elapsed allowing for bone remodeling. Moreover,

it has to be mentioned that DFDBA is usually more

expensive than FDBA.

Cortical FDBA vs. Cancellous FDBA

vs Cortico-cancellous 50/50 Mix

Cortical FDBA due to its higher mineral content has

been suggested to be more resistant to compressive

forces and ultimately could allow better dimensional

stability following ridge preservation. On the other

side, cancellous FDBA is more porous and could

therefore allow better vascularization of the graft

and improved bone formation due to its increased

surface area. Demetter et al. (2017) in a similar

approach to the previous study showed that the use

of cortical FDBA for ridge preservation resulted in

more residual graft particles. However, no difference

were seen in the relative amount of native bone and

non-mineralized connective tissue between the three

groups. Additionally, no significant differences were

observed in the dimensional ridge changes between

the three groups . These three materials seem to

work equally well for ridge preservation purposes.

FDBA vs. 70% FDBA + 30% DFDBA

Recently, commercially available products have

come on the market combining FDBA and DFDBA

in a single product, potentially taking advantage of

their respective advantageous properties. Borg and

Mealey (2016) reported that ridge dimensions were

equally well maintained with the combination product

and FDBA following ridge preservation. However, the

combination product led to significantly more vital

bone and less residual graft particles after 18 to 20

weeks of healing.

Clinical Signiﬁcance

Given the plethora of bone grafting materials and

barriers on the market it may not be possible to find

scientific data for each of them. Recent systematic

reviews (Vignoletti

et al

. 2012, Atieh

et al.

2015,

Avila-Ortiz 2019) suggest that there is no evidence to

supports the use of a specific material over another

for the purpose of maintaining ridge dimensions

following extractions.

Also, while intuitively it would be advantageous

to have a grafting material that would result in

more vital bone and less residual graft material

in the prospective implant site, it is unknown if

these parameters will influence short and long-term

implant success (Chan

et al.

2013, Avila-Ortiz

et al.

2019)