The Survival Rate of RBM Surface Versus SLA Surface Implants Placed in Posterior Maxilla With Sinus Augmentation Procedure
Currently, the two major subtractive surfaces in clinical use are the SLA surface and the RBM surface. SLA
surface is created first by sandblasting with large grit particles then followed by acid etching to remove the
remaining particles and further increase the roughness. The SLA surface has surface average roughness (Sa
1.78μm). One study that looked at the survival rate of SLA implants found that after 10 years period of follow up,
these implants had 98% survival rate. Simone et al. also reported survival rate for SLA surfaced implants of
82.94% after a follow up period of 10-16 years. Resorbable blast media surface (RBM) is formed through
propelling resorbable coarse bioceramics (calcium phosphate) particles on titanium metal substrate followed by
passivation process aiming to increase the level of roughness and enhance the osseointegration capability of the
implant. One of the advantages of this technique is gained via the use of calcium phosphate particles that
eliminates the risk of leaving contaminating debris after blasting. Leaving contaminated surface is considered a
common drawback for using other less biocompatible blasting materials. RBM surface possesses
average roughness around 1.5μm. In one animal study, RBM surface had a higher bone to implant contact after
90 days than either of TPS, HA coated, and smooth surface implants. As far as RBM surface survival rate is a
concern, studies have reported comparable survival rate of 95.37% after 7 years of follow up period.
With regard to comparing the effect of the implant surface characteristics on the survival rate, the literature is rich
with large numbers of studies investigating this issue but all of the previously studies cited in this article have
compared different implant surfaces on different geometrical design. For example, Al Nawas et al. compared the
survival rate of turned surfaced implants from Nobel Biocare to double acid etched surfaced implants from Biomet
3i. After periods of 49 months follow up, no difference in the survival rate has been found between the two
surfaces. Another similar study by Khang et al. that compared the survival rate of machined surfaced implants to
double acid etched surfaced implants found that the latter had a 9% higher survival rate of 95%.
According to the author’s knowledge, there is a scarcity of clinical studies that compare the survival rates of two
surfaces with the same exact body design. One study by Li et al. compared the removal torque and the bone
response of two identical implants with either SLA surface, machined surface, or dual acid etched surface and
found that SLA surface achieved a better bone anchorage and had more than 5% higher stiffness of the removal
torque test. Therefore, the aim of this study was to evaluate and discuss the survival rate of SLA surface to RBM
surface for implants with identical geometrical design.
MATERIALS AND METHODS
The study included 47 implants with RBM surface and 22 implants with SLA surface. All of the survived implants
are restored and in function at the time of this study. The follow up time since the implants were restored ranged
from 4 to 32 months. The study included only patients who had received implants of the same identical
geometrical design and had either RBM or SLA surface.
Total 83 implants placed. Simultaneously placed implant is 83%(69/83). Delayed implant placement is
17%(14/83). Simultaneous implant success rate is 97%. Most distal implants are failed in simultaneous implant
placement. Average implant length of simultaneous implant placement is 12.7mm. Average implant length of
delayed implant placement is 11.8mm. Average implant diameter of simultaneous implant placement is 4.4mm.
Average implant diameter of delayed implant placement is 4.3mm.
According to limited number of results, RBM surface and SLA surfaced implants demonstrated similar success
rate (97 vs 95). However, simultaneously placed implants show longer (12.7 vs 11.8) and wider (4.4 vs 4.3)
implant. Therefore simultaneous implant placement is preferred if possible. Need randomized control long term
study is is necessary to verify this results.