Does Sinus Membrane Perforation Affect Implant Survival?


Retrospective data was obtained from 23 patients who had undergone sinus augmentation procedures with a total of 40 treated sinuses.  Sinuses were grafted with mineralized cancellous bone allograft, anorganic bovine bone matrix, or biphasic calcium phosphate.  There were 15 perforated sinuses which were repaired with an absorbable collagen membrane.  Histologic cores were taken from all treated sinuses 26 to 32 weeks after surgery.  


Average percentage of vital bone was 26.3% ± 6.3% in the repaired sinuses versus 19.1% ± 6.3% in the non-perforated sinuses.  The implant success rate was 100% in the repaired sinuses versus 95.5% in the non-perforated sinuses.  There was no statistically significant difference in the failure rates.


There was greater vital bone formation in the repaired sinuses compared to the non-perforated sinuses after augmentation.  When properly repaired, maxillary sinus membrane perforations do not appear to adversely affect vital bone formation or implant survival.

Dr. Gebrael’s comments:

Interesting enough we see more vital bone formation in the repaired sinuses after grafting.  The authors of the study indicate this may be due to the membrane over the perforation acting as a second barrier that prevents soft tissue migration and immobilizes the graft particles.

For more information please refer to:

Effect of maxillary sinus membrane perforation on vital bone formation and implant survival: a retrospective study.

Froum SJ, Khouly I, Favero G, Cho SC.

J Periodontol. 2013 Aug;84(8):1094-9


How Much Tissue Rebound After Crown Lengthening?



Sixty-four patients requiring crown lengthening on 64 teeth were included.  Bone was reduced based on the minimal amount of tooth structure required for restoration.  Patients were re-evaluated at 3 and 6 months.




There was significant soft tissue rebound (0.77 ± 0.58 mm) at 6 months post crown lengthening surgery.  The tissue rebound was significantly correlated with periodontal biotype: Thick-flat biotype experienced more tissue rebound (0.7 mm) than thin-scalloped biotype (0.37 mm).  Less tissue rebound was seen when the flap margin was further from the osseous crest after suturing.




Suturing the flap ≥ 3 mm from the osseous crest after surgery will minimize soft tissue rebound.  There was more tissue rebound and less crown length gained when a thick-flap biotype was present.


For more information refer to

Evaluation of supracrestal gingival tissue after surgical crown lengthening: a 6-month clinical study.

Arora R, Narula SC, Sharma RK, Tewari S.


J Periodontol. 2013 Jul;84(7):934-40

Are Short Implants (< 10 mm) Effective?


A meta-analysis on prospective clinical trials yielded thirteen studies with 1,955 dental implants, of which 914 were short implants < 10 mm in length.




Short implants had an estimated survival rate of 88.1% at 168 months, compared to a similar survival rate of 86.7% for standard implants (P=0.254).  The peak failure rate for short dental implants occurred between 4 and 6 years of function.  The peak failure rate for standard implants occurred between 6 and 8 years of function.




Similar long term survival rates for implants < 10 mm in length compared to longer implants.  When implant failure did occur, it was at an earlier stage for the shorter implants.


Dr. Gebrael’s Comments:

Bone augmentation procedures have limitations and may not be acceptable to many patients due to increases in cost, treatment duration, and site morbidity.  Short implants can be used with a good long term survival rate. This meta-analysis however was not able to determine the influence of bone density or type of prosthetic reconstruction on implant survival.




Are Short Dental Implants (< 10mm) Effective?

A Meta-Analysis on Prospective Clinical Trials


Monje A, Chan HL, Fu JH, Suarez F, Galindo-Moreno P, Wang HM

Journal of Periodontology July 2013, Vol. 84, No. 7, Pages 895- 904