A Paradigm Shift in Prosthetic Dentistry

Learning Objectives
Review studies evaluating Teeth adjacent to treated and untreated bounded edentulous spaces
Review studies on long-term success rate for Endo-treated teeth
Review the evidence on Fixed partial denture survival analysis studies
Evaluate long-term outcomes on Implant Supported Restorations
Evaluate clinical studies with the Straumann Dental Implant System

Terminology
Immediate Loading: same day or within 24 hours loading
Immediate Temporization: Placement of temporary restoration (out of occlusion) at the time of surgery
Early Loading: loading 3-8 weeks after placement
Delayed Loading: 3 to 6 months loading
One-stage system: only one surgery is required
Two-stage system: a 2nd surgery is required for implant uncovering

Survival rates of Teeth Bounded to Edentulous Spaces
VA Medical Center Longitudinal Study- Shugars JADA 1998:1089-1095
- 19% of adjacent teeth failed if untreated
- 10% failed if treated with FPD
- 30 % failed if treated with RPD
Aquilino SA J Prosthetic Dentistry- Retrospective study 317 patients –
- 10 year survival rate for RPDs 56%
- 10 year survival rate for FPDs 90 %

Conclusions
There is significant loss of adjacent teeth (19%) if the missing tooth is not replaced.
FPDs improved survival rate, with abutment tooth loss of 10% at 10 years
RPDs increased abutment tooth failure rate ranging from 30% to 44%

Fixed Partial Denture Survival Studies
Biologic failures: caries, periodontal disease, endodontic or periapical problems.
Mechanical failures: loss of retention, porcelain fracture, wear of gold restoration, framework fracture defective margins, poor contours, poor esthetics.

FPD Survival Rate Studies
Palmquist. Int J Pros 1993;6:279-285
103 FPD 18-23 year Survival: 79%
Lindquist. Int J Pros 1998;11:133-138
140 FPD. 20 years Success 65%
Hammerle Int J Pros 2000:13:409-415
115 FPD and 229 abutment teeth. 5-16 years. 12% lost vitality, 8% secondary caries, 8% loss of retention, and 3% tooth fracture
Scurria MS JPD 1998; 79:459-464
Meta-analysis of 9 studies. 2761 abutment teeth 3-20.5 years. 10-year survival 85%- 15-year 66%

More FPD long-term studies
De Backer H Int J Prosthodont 2006
3- unit FPD survival rate: 73.1%
Main reason for failures was caries (38.1%)
De Backer H Int J Prosthodont 2008
4- unit FPD survival rate: 68.3%
Main cause for irreversible failure was caries (32%)

Conclusions
Studies seem to be in agreement that FPD’s are about 66% successful for periods of 15 years.
Several studies indicate that the mean lifespan for FPDs is about 10 years
Various studies report abutment tooth loss ranging from 2% to 30% for periods of 8 to 14 years.

Implant Survival Analysis
Immediate success rate is >98% and after 1st year of function, failure rate is very low.
Priest GF IJOMI 1999;14:181-188. 99 patients with 116 implants & 112 single tooth implant prostheses – 10 years Survival rate 97.4%
Eckert S and Sanchez A. IJOMI 2005. 7398 implants (5 implant systems) Survival rate 96%.
Gomez-Roman IJOMI 1997;12:209-309. 376 patients with 696 implants (300 single crowns) 5 years Survival rate 96%
Lindhe et al. Clin Oral Impl Res 1998;9:80-90 (meta-analysis of 19 studies) 2686 implants: 570 single crowns 2116 in FPD. 7 years. Survival rate FPD 93.6%, Single crown 97.5%.

More Survival Rate Studies
Lekholm et al. Clin Implant Dent Relat Res 2006;8:178-186. 17 partially edentulous patients with 69 Branemark implants. Survival rate 91% at 20 years.
Astrand P et al. Clin Implant Dent Relat Res 2008 April. 21 totally edentulous patients with 123 implants were evaluated. Survival rate 99.1%

Summary
Treatment options for tooth replacement have different success rates
FPDs 85% successful at 10 years 66% successful at 15 years
69% successful at 20 years
Implant-Supported Prostheses
- 96% successful at 5 years
- 91-99.2% successful at 20 years

Advantages of Implant-supported Vs. Fixed Partial Prosthesis
Preservation of tooth structure
Preservation of bone structure
Preservation of soft tissue esthetics
Improved ability for OHI
Improved Quality of Life
Decreased risk for caries

Clinical Studies on the Straumann System

Solid Screw implants for
Posterior Replacement
Levine et al. 2002 IJOMI .
Retrospective analysis 675 posterior single-tooth implants were restored in 471 patients with average time of loading 21.30 months.
A cumulative survival rate of 99.1% was obtained for all sites (6 failures).
Minimal restorative problems were found with either screw-retained (n = 71) or cemented restorations on solid abutments (n = 600); 80.3% of screw-retained and 98.2% of cemented restorations were free of complications, respectively. Patient satisfaction scores were high (97.4%)
The data suggest that solid-screw(4.1 or 4.8 mm wide) Straumann implants can be an excellent choice for posterior single-tooth restorations.

Multicenter Retrospective Analysis of Wide-neck Dental Implants
Levine R et al. (IJOMI 2008) evaluated the predictability of Straumann 1-stage wide-neck SLA implants used for molar replacement.
499 implants in 410 patients were assessed with a mean loading time of 24 months. 359 implants were placed in the mandible, 148 in the maxilla.
Cumulative survival rates was 99.2% for mandibular molars, and 96.6% for maxillary molars.
This data suggest that the 1-stage solid-screw wide-neck implant is a good choice for molar single-tooth replacement.

Straumann SLA vs
Nobel Ti-Unite Surface
Jung et al. J Periodontology 2008,79:1857-1863 (October issue)
5 year comparative study
Mandibular posterior single implants
193 implants with SLA surface; 112 implants with Ti-unite surface.
Survival rate for SLA 99%, Ti-unite 96%

Shorter implants vs. Longer Implants
Fugazzotto (IJOMI 2008). Retrospective study in patients receiving Straumann tissue level implants that were less than 10 mm in length.
A total of 2,073 implants were assessed in 1,774 patients. Implants were 6, 7, 8, or 9 mm supporting single crowns or short-span fixed prostheses.
Cumulative survival rates ranged from 98.1% to 99.7%.
Conclusions: with proper case selection and utilization, shorter implants demonstrate a success rate comparable to those reported for longer implants.

Long-term Clinical Study on Full Arch Immediate Loading Implants
Kinsel (IJOMI 2007). Retrospective study on 344 single-stage Straumann on 43 patients with 56 edentulous arches immediately loaded with 1-piece provisional prosthesis.
Follow-up 2 to 10 years. A total of 16 implants failed to integrate, with a survival rate of 95.3%.
Reduced implant length was the sole significant predictor for failure.

SLActive Surface Technology

Clinical Studies on SLActive
Surface Technology
Oates et al (IJOMI 2007) completed RCT on chemically modified large-grit, acid-etched (SLA) in 31 patients.
Each patient received 2 implants with the same physical properties but with surfaces that were chemically different.
Resonance frequency analysis was assessed weekly for 6 weeks after implant placement.
All implants were proven clinically successful allowing for restoration.
A shift from decreasing to increasing stability occurred at 2 weeks for SLActive implants versus 4 weeks for SLA implants.
This study demonstrates that chemical modification of SLA surface to alter the biologic events of the osseointegration process may be associated with enhance healing response.

SLActive® multi-center study
Ganeles et al (in press Clinical Oral Implant Research)
The 1-year results of SLActive® multi-center study have been accepted by Clinical Oral Implants Research.
At one year after implant placement, the study concluded the following:
Immediate and early loading with Straumann® SLActive implants yields excellent survival rates
(98 % and 97 % after 1 year)
Immediate loading is as successful as early loading with Straumann® SLActive implants
Successful implant treatment is possible with Straumann® SLActive even in poor quality bone
No implant failures were evident in Type IV bone

Crestal Bone Preservation

Crestal bone preservation with Platform Switching
IJOMI (under review). Marginal bone height and BMD at 1-year post-loading of Bone level SLActive Straumann Implants
A total of 137 implants in 21 patients were inserted. Implant stability and bone height was measure at implant placement and 1 year follow-up. All implants received immediate loading. BMD and bone height did not differ at the 1-year visit from baseline measurements.

Bottom Line
Solid-screw(4.1 or 4.8 mm wide-neck) Straumann implants can be a satisfactory choice for posterior single-tooth restorations (99% survival rate)
With proper case selection and utilization, shorter implants demonstrate a success rate comparable to those reported for longer implants.
In fully edentulous cases, immediate implant loading demonstrates a high success rate similar to delayed loading cases.
Immediate implant loading should be avoided with shorter implants.
Chemical modification of SLA surface enhance the osseointegration process.
Short-term clinical studies demonstrate preservation of crestal bone, and excellent survival rates for SLActive Implants
In short-term studies, immediate loading of Straumann® SLActive implants is as successful as early loading.
Long-term studies are needed before we can make final recommendations of loading protocols with SLActive implants.