Clinical Evaluation Of Short Implant In Atrophic Posterior Region

Objective:Aimed to study clinical effect of short implant in atrophic posterior region and to provide some references and guidances for the reasonable application of short implant in clinical practice.Methods:There were 123 patients with 154 short implants implanted in atrophic posterior region in Yantai stomatological hospital implanting center from January 2010 to January 2013.The study selected 97 patients who participated in clinical examinations,including 54 cases of male patients,43 cases of female patients,24～78 years old,average age 48.4±9.3 years old.Implant systems include:American Bicon implant system,Swiss Straumann implant system,Korea Dentium implant system.One hundred twenty-one short implants were included in the study and all implants have been loaded.We observed and recorded the relevant indicators,including:implant survival rate,implant success rate,margin bone resorption,crown-implant ratio,probing depth,patient satisfactions and complications,etc.The data was imported into SPSS statistical software for analysis,comparing the differences in the health status of soft and hard tissue around short implants among different implant systems.P<0.05 statistically significant.Results:(1)Three implants didn’t meet the success criteria,one implant was removed,two implants were diagnosed as peri-implantitis,which were remained stable after conservative treatments.The implant survival rate was 99.2%and implant success rate was 97.5%.(2)The average C/I of short implants was 1.49 ± 0.42,among which C/I≤1 was 17,1<C/I≤2 was 87 and C/I>2 was 16.Bicon group(1.77±0.34)was significantly higher than other two groups(P<0.05).There was no significant difference between Straumann group(1.21±0.34)and Dentium group(1.34±0.36)(P>0.05).(3)The change of bone in the proximal margin of short implants was-0.25± 0.81 mm,and the change of the distal bone level was-0.24±0.57 mm.The bone absorb values of Bicon,Straumann and Dentium were 0.25±0.65 mm,0.24 ± 0.88 mm and 0.25±0.48 mm,respectively.There were no significant difference between any two groups(P>0.05).In addition,there was no correlation between C/I and marginal bone resorption(P>0.05).(4)The width of keratinized gingival of short implants was range from 0 to 7 mm.,the overall average was 2.51 ±1,89 mm.The width of keratinized gingival of Bicon,Straumann and Dentium were 2.36±1.73 mm,2.67±2.09 mm and 2.57±2.23 mm,respectively.There was no significant difference between any two groups(P>0.05).(5)The average plaque index of short implants was 1.07±0.87,Bicon,Straumann and Dentium implants were 1.08±0.88,0.89±0.88 and 1.30±0.85,respectively.The Straumann group was statistically significant difference compared with Dentium group(P<0.05).(6)Most short implants bleeding symptom was mild,24.8%of short implants were not bleeding and 47.1%of short implants had a bleeding index of 1.Gingival sulcus linear bleeding was about 19.8%,few implants(8.3%)bleeding index were 3,for severe bleeding.The mean bleeding index of Bicon,Straumann and Dentium implants were 1.11 ±0.83,1.04±0.89,1.21±0.92,respectively.There was no significant difference between these groups(P>0.05).(7)The average probing depth of short implants was 3.11 ±1.23 mm,higher than the probing depth of healthy natural teeth(PD≤3 mm).The probing depth of Bicon,Straumann and Dentium were 3.08±1.19mm,3.11±1.29 mm,3.141.18 mm,respectively.There was no significant difference between these groups(P>0.05).(8)The overall complication rate of short implants was 39.7%,the minimum incidence of complication was postoperative bleeding,reaching 0.8%.The highest incidence was food impaction;reaching 48.8%.There was a significant correlation between the food impaction sites and bone resorption around short implants(P<0.05).(9)The overall OHIP-I score of the short implants was significantly lower(2.62 ± 0.25)than preoperative(17.74±0.85)with statistical difference(P<0.05).But there was no significant difference among three implant systems regardless of preoperative or postoperative(P>0.05).Conclusions:(1)The use of short implants in atrophic posterior region can replace complex surgeries,reduce the incidence of complications,healing time and cost,the patient satisfaction is higher.(2)Bone tissue around short implants can remain stable,there is no association between C/I and bone resorption.When the jaw gingival distance is large(C/I≥1.5),Bicon implant system have more advantages.(3)The highest incidence of complications is food impaction(48.8%).