Literature update OctorberJuly 2009
Australian Dental Journal Vol.54, No.2 (June 2009)
Nixoc KC, Chan ST, Ivanovski S Aretrospective Analysis of 1000 Consecutively placed implants in private practice, Aust Den J 2009; 54 (2):123 - 129
From 1.000 consecutively placed implant, data on patient demographics, implant placed, time of placement, loading protocols, augmentation procedures, prothese and outcomes were obtained. Most patient (88,6%) received one or two implants. The cumulative survival and success rates was 99.2% and 93.1% after 5 years, 98.4% and 99.9 % after 10 years, indicating that high success and survical can be achieved in private practice with careful treatment planning and adherence to specific protocal.
Clinical Oral Implant Research, Vol.20, No.6 (June 2009)
Emami E, Heydecke G, Rompré PH, de Grandmont P, Feine JS. Impact of implant support for mandibular
dentures on satisfaction, oral and general health-related quality of life: a meta-analysis of randomized-
controlled trials. Clin Oral Implants Res 2009;20(6):533-544.
Various scientific databases were searched for articles on the efficacy of mandibular implant-retained
overdentures compared to conventional dentures. The search identified ten publications, of which eight were
included in the meta-analysis. Implant overdentures were found to be more satisfactory at a clinically
relevant level, but statistical heterogeneity was found and there was a lack of evidence for the impact of
implant overdentures on perceived general health. Although overdentures may be more satisfying for
patients, the degree of the effect is not yet certain and additional investigations are necessary.
Araújo MG, Lindhe J. Ridge alterations following tooth extraction with and without flap elevation: an
experimental study in the dog. Clin Oral Implants Res 2009;20(6):545-549.
Second mandibular premolars were hemisected in five dogs; on one side the distal root was removed via
full-thickness flaps, while the root was removed in a flapless procedure in the other side. Removal of a root
during healing caused a marked change in the edentulous ridge. Minor alterations were seen in the apical
and middle portions, but substantial hard tissue was lost coronally. Hard tissue loss was similar with both
surgical procedures; therefore, the procedure did not affect long-term healing outcomes.
Nickenig H-J, Wichmann M, Schlegel KA, Nkenke E, Eitner S. Radiographic evaluation of marginal bone
levels adjacent to parallel-screw cylinder machined-neck implants and rough-surfaced microthreaded
implants using digitized panoramic radiographs. Clin Oral Implants Res 2009;20(6):550-554.
A total of 133 implants (70 rough-surfaced and 63 machined-neck) were placed in 34 patients, with marginal
bone levels evaluated for up to 2 years (median follow-up 1.9 years). Mean bone loss values after the
healing period, 6 months and end of follow-up were 0.5 mm, 0.8 mm and 1.1 mm for machined-neck
implants and 0.1 mm, 0.4 mm and 0.5 mm for the rough-surfaced microthreaded implants, respectively; bone
loss was therefore significantly lower with the microthreaded implants.
Fenner M, Vairaktaris E, Fischer K, Schlegel KA, Neukam FW, Nkenke E. Influence of residual alveolar bone
height on osseointegration of implants in the maxilla: a pilot study. Clin Oral Implants Res 2009;20(6):555-
Premolars and molars were removed in one side of the maxilla in minipigs, and cavities created to produce
residual bone heights of 2, 4, 6 and 8 mm. Implants were then placed and loaded after 6 months. After a
further 6 months, histology and histomorphometry showed significantly greater BIC for 6 mm versus 2 and 4
mm on the buccal aspect, and significantly greater for 6 and 8 mm versus 2 and 4 mm on the palatal aspect.
Crestal bone resorption was significantly lower for an alveolar height of 8 mm. Osseous integration was not
hindered by reduced residual bone height, but the greatest predictability was found with alveolar heights of 6
and 8 mm.
Bouchard P, Renouard F, Bourgeois D, Fromentin O, Jeanneret MH, Beresniak A. Cost-effectiveness
modeling of dental implant vs. bridge. Clin Oral Implants Res 2009;20(6):583-587.
A decision framework was used to model cost-effectiveness of an implant strategy versus a fixed partial
denture strategy for single-tooth replacement. Transition probabilities were programmed from literature,
expert opinions and epidemiological reports, simulating practice and patient variability, with direct medical
costs assessed according to a cost survey. The implant strategy was found to be significantly more cost-
effective (total mean cost EUR 3517 ± 1338 versus EUR 4385 ± 2629 per patients over 20 years), and
appeared to be the ‘dominant’ strategy.
Gallucci GO, Doughtie CB, Hwang JW, Fiorellini JP, Weber H-P. Five-year results of fixed implant-supported
rehabilitations with distal cantilevers for the edentulous mandible. Clin Oral Implants Res 2009;20(6):601-
Implant-supported mandibular hybrid prostheses with distal cantilever extensions on 237 implants were
placed in 45 patients, and biological, implant and prosthetic parameters evaluated from implant placement up
to 5 years. Mean cantilever length was 15.6 mm (range 6 to 21 mm). There were no implant failures, and the
prosthesis survival rate was 95.5%, with a treatment success rate of 86.7% (six patients did not meet the
criteria for success). The majority of complications were technical (54/79), and most of these involved
fracture of the acrylic teeth and base (20/54). Rehabilitation with mandibular hybrid cantilever prostheses on
implants was therefore a reliable treatment.
European Journal of Oral Implantology Vol. 2 No. 1 (May 2009)
Felice P, Cannizzaro G, Checci V, Marchetti C, Pellegrino G, Censi P, Esposito M. Vertical bone
augmentation versus 7-mm-long implants in posterior atrophic mandibles. Results of a randomized
controlled clinical trial of up to 4 months after loading. Eur J Oral Implantol 2009;2(1):7-20.
Two or three submerged implants with a length of 7 mm were placed in each of 30 patients with 7-8 mm
residual crest height and ≥ 5.5 mm thickness, while 10 mm implants were placed in vertically augmented
bone in another 30 patients. Acrylic prostheses were placed after 4 months, and definitive metal-ceramic
prostheses were placed after another 4 months. In two patients, 10 mm implants could not be placed, so 7
mm implants were placed instead. Due to implant failures, three prostheses were unable to be placed in the
10 mm group, compared to one in the 7 mm group; the prostheses were delivered after implant replacement.
There were four complications in the 10 mm group, versus none in the 7 mm group, and mental nerve
sensitivity was recovered more rapidly in the 7 mm group.
Cannizzaro G, Felice P, Leone M, Viola P, Esposito M. Early loading of implants in the atrophic posterior
maxilla: lateral sinus lift with autogenous bone and Bio-Oss versus crestal mini sinus lift and 8-mm
hydroxyapatite-coated implants. A randomised controlled clinical trial. Eur J Oral Implantol 2009;2(1):25-38.
In 40 patients with 3-6 mm residual crestal bone height and ≥ 4 mm thickness below the maxillary sinus,
either lateral sinus lift with Bio-Oss + autogenous bone and placement of 10-16 mm long implants, or mini
sinus lift with autogenous bone and placement of 8 mm implants was performed. Provisional prostheses
were placed after 45 days, and final prostheses after a further 45 days. Primary stability was not obtained in
three patients in the short implant group, so larger diameter implants were used. There was one implant
failure in the short implant group, compared to five implant failures in the longer implant group. Two major
complications occurred in the longer implant group, leading to four implant failures, but there was no
significant difference in complications between the groups. Short implants may therefore be a suitable
treatment option in some patients.
Implant Dentistry Vol. 18 No. 3 (June 2009)
Senay C, Akça K. Biomechanical aspects of bone-level diameter shifting at implant-abutment interface.
Implant Dent 2009;18(3):239-248.
Model systems of load distribution at the implant-abutment interface under vertical and oblique loading
conditions were evaluated with platform-switched and conventional interfaces. The stress distribution at the
peri-implant bone was similar with similar magnitudes, but higher stress forces were observed with increased
horizontal set-off distances, with increased stress intensity within the implant-abutment complex. Platform
switching therefore does not influence stress characterization but may influence the mechanical properties of
the connection. More mechanical studies are therefore required on the concept of platform switching.
Schrotenboer J, Tsao Y-P, Kinariwala V, Wang H-L. Effect of platform switching on implant crest bone
stress: a finite element analysis. Implant Dent 2009;18(3):260-269.
A 2-dimensional finite element analysis was designed with a 4 mm diameter implant and abutments with
diameters of 4.5 mm or 5 mm. Vertical and oblique static loads of 100 N were applied. Maximum Von Mises
stresses were 28 MPa for oblique loading and 6.977 MPa for vertical loading with the 5 mm abutment, and
27.43 MPa for oblique loading and 6.502 MPa for vertical loading for the 4.5 mm abutment. Slight differences
in the stress distribution patterns were also noted; the differences were greater for vertical loading. The effect
of platform switching on crestal bone stress was therefore minimal but measurable.
International Journal of Oral and Maxillofacial Implants Vol. 24 No. 2 (March/April
Calvo-Guirado JL, Ortiz-Ruiz AJ, Lopez-Mari L, Delgado-Ruiz R, Mate-Sanchez J, Gonzalez LAB.
Immediate maxillary restoration of single-tooth implants using platform switching for crestal bone
preservation: a 12-month study. Int J Oral Maxillofac Implants 2009;24(2):275-281.
In 50 patients with at least one maxillary failing tooth, 61 implants were placed, with definitive restorations
provided after 15 days and bone levels assessed after 125 days and 1, 2, 3, 6, 8 and 12 months. There was
one implant failure and one implant was lost to follow-up. Mean mesial and distal bone loss after 12 months
was 0.08 ± 0.53 mm and 0.09 ± 0.65 mm, respectively, and the mean implant stability (measured by RFA)
was 71.1 ± 6.2. The implants were therefore stable over the course of a year, with minimal crestal bone loss.
Prosper L, Redaelli S, Pasi M, Zarone F, Radaelli G, Gherlone EF. A randomized prospective multicenter
trial evaluating the platform-switching technique for the prevention of postrestorative crestal bone loss. Int J
Oral Maxillofac Implants 2009;24(2):299-308.
In 12 centers, 60 patients received either platform-enlarged or cylindrical implants via a non-submerged,
submerged or submerged with reduced diameter abutment (platform switched) technique. Sixty implants
were placed in each group (total of 360 implants). For control implants, there were three failures in the
second year, and there was significantly greater bone loss at cylindrical implants than platform-enlarged or
platform-switched implants. Crestal bone preservation was found to be superior at submerged implants with
an enlarged platform than those with a reduced abutment. Implants with a larger platform may therefore have
better crestal bone preservation than implants with a reduced diameter abutment.
Bahat O. Technique for placement of oxidized titanium implants in compromised maxillary bone: prospective
study of 290 implants in 126 consecutive patients followed for a minimum of 3 years after loading. Int J Oral
Maxillofac Implants 2009;24(2):335-334.
In 126 implants, 290 implants were placed in compromised bone, with a provisional prosthesis placed after
at least 6 months. The follow-up time was at least 3 years. Approximately half the implants required second-
stage uncovering, and two implants failed to osseointegrate, giving an implant survival rate of 99.3% over 3
years. Mean changes in marginal bone level were -2.70 mm, -2.67 mm and -2.74 mm after 1, 2 and 3 years,
respectively. The implants therefore gave predictable prosthetic support over 3 years, with stable marginal
International Journal of Periodontics and Restorative Dentistry Vol. 29 No. 2
Rodriguez-Ciurana X, Vela-Nebot X, Segala-Torres M, Calvo-Guirado JL, Mendez-Blanco V, Tarnow DP.
The effect of interimplant distance on the height of the interimplant bone crest when using platform-switched
implants. Int J Periodontics Restorative Dent 2009;29(2):141-151.
Bone resorption patterns around platform-switched implants were investigated using 41 pairs of implants
placed < 3 mm apart in 37 patients. The mean horizontal and vertical bone resorption was 0.60 mm and 0.62
mm, respectively. The mean bone preservation above a reference line between the two implant-abutment
interfaces was 0.24 mm.
Mellonig JT, Valderrama M del P, Cochran DL. Histological and clinical evaluation of recombinant human
platelet-derived growth factor combined with beta tricalcium phosphate for the treatment of human class III
furcation defects. Int J Periodontics Restorative Dent 2009;29(2):169-177.
Class III furcation defects in hopeless mandibular first molars in four patients were surgically exposed and,
after root planing, were grafted with recombinant human platelet-derived growth factor and β-tricalcium
phosphate and a collagen barrier membrane placed on the facial and lingual surfaces. The patients were
evaluated every 2 weeks for 6 months, after which time a reduction in probing depth and a gain in clinical
attachment level were observed. One furcation defect was reduced to class II, but the others remained as
class III. Histological evaluation of the teeth showed periodontal regeneration on three root surfaces, new
attachment on three surfaces and junctional epithelium on one surface.
MacDonald K, Pharoah M, Todescan R, Deporter D. Use of sintered porous-surfaced dental implants to
restore single teeth in the maxilla: a 7- to 9-year follow-up. Int J Periodontics Restorative Dent
A total of 20 patients each received a single implant to replace premolar or molar teeth (65%) or anterior
teeth (35%). Crestal bone levels and papilla formation were evaluated, and 17 implants were available for
assessment after 7-9 years. The implant survival rate was 92.9% (one implant was removed due to
excessive bone loss). The success rate was also 92.9%, and there were no significant changes in mean
annual bone loss from 1 to 9 years.
International Journal of Prosthodontics Vol. 22 No. 2 (March/April 2009)
Walton TR. Changes in patient and FDP profiles following the introduction of osseointegrated implant
dentistry in a prosthodontic practice. Int J Prosthodont 2009;22(2):127-135.
Implant- and tooth-supported prostheses placed over a 23-year period were tabulated and analyzed. From
1984 to 1991, tooth-supported single crowns and tooth-supported FDPs comprised the majority of cases
(97%), but the number of implant-supported prostheses increased rapidly from 1991 to 2007, when the
majority of cases were implant-supported FPDs (81%). More of both types of prostheses were placed in
females, but more implant-supported FDPs were placed in patients < 31 years of age. From 1984 to 2007
there was also a decrease in the number of three-unit tooth-supported FPDs, tooth-supported FPDs with four
or five pontics and in teeth with an unfavorable 10-year prognosis. The advent of implant dentistry in a
clinical practice setting therefore resulted in measurable changes in prosthesis and patient profiles.
Visser A, Raghoebar GM, Meijer HJA, Vissink A. Implant-retained maxillary overdentures on milled bar
suprastructures: a 10-year follow-up of surgical and prosthetic care and aftercare. Int J Prosthodont
Each of 39 edentulous patients received six implants and a milled bar mesostructure to support a maxillary
overdenture. Follow-up evaluations, evaluating prosthetic care and aftercare, were performed for up to 10
years. Three patient groups were identified: those with lack of retention on conventional dentures due to
anatomic problems; those with gagging problems; and, those not tolerating a conventional maxillary denture.
The implant survival rate over 10 years was 86.1%; most implant losses were in the first year. Most surgical
aftercare involved the removal and replacement of implants, while most prosthetic aftercare involved routine
inspections, oral hygiene care and activation or replacement of attachments. Implant-retained maxillary
overdentures were therefore shown to be a predictable and reliable treatment option with little after care
Journal of Biomedical Materials Research Part B Applied Biomaterials Vol. 90 No. 1 (July 2009)
Jensen SS, Bornstein MM, Dard M, Bosshardt DD, Buser D. Comparative study of biphasic calcium
phosphates with different HA/TCP ratios in mandibular bone defects. A long-term histomorphometric study in
minipigs. J Biomed Mater Res B Appl Biomater 2009;90(1):171-181.
Defects were prepared in the mandibles of 24 minipigs and treated with hydroxyapatite/tricalcium phosphate
in three different ratios (20/80, 60/40 and 80/20) compared to autogenous bone, deproteinized bovine bone
mineral (DBBM) or coagulum as controls. Bone formation and filler degradation of HA/TCP 20/80 was similar
to autogenous bone, while HA/TCP 60/40 and 80/20 were similar to DBBM. For all three test materials, bone
formation and filler degradation was inversely proportional to the HA/TCP ratio. At all time points (4, 13, 26
and 52 weeks), autogenous bone showed the highest fraction of filler surface covered with bone, while the
fraction was higher for DBBM than HA/TCP 80/20 and 60/40 in the early healing phase.
Journal of Clinical Periodontology Vol. 36 No. 6 (June 2009)
Savage A, Eaton KA, Moles DR, Needleman I. A systematic review of definitions of periodontitis and
methods that have been used to identify this disease. J Clin Periodontol 2009;36(6):458-467.
The authors performed a literature search to identify relevant papers with definitions and measurements of
periodontitis, excluding papers on gingivitis, intervention studies or prevalence and severity. From 3,472
potential papers, 104 were identified, of which 15 met the criteria for review. Heterogeneity was noted among
the measurement tools used and in the use of clinical attachment loss and probing depth as criteria for the
disease. The threshold for diagnosis was between 2 to ≥ 6 mm when clinical attachment loss was used and
between 3 to ≥ 6 mm when probing depth was used. Epidemiological studies of the disease are therefore
complicated by differences in methodologies and definitions.
Becker J, Ferrari D, Mihatovic I, Sahm N, Schaer A, Schwarz F. Stability of crestal bone level at platform-
switched non-submerged titanium implants: a histomorphometrical study in dogs. J Clin Periodontol
In the mandibles of 12 dogs, 72 implants were placed 0.4 mm above the crestal bone level and matching or
non-matching healing abutments were placed. Histomorphometric analysis was performed after 4, 8, 12 and
24 weeks. After 24 weeks, there were no significant differences in the measurements of implant shoulder to
apical extension of long junctional epithelium, implant shoulder to most coronal bone-to-implant contact or
implant shoulder to alveolar bone crest. The authors concluded that platform switching may not be crucially
important in maintaining the crestal bone level.
Journal of Periodontology Vol. 80 No. 5 (May 2009)
Cochran DL, Nummikoski PV, Schoolfield JD, Jones AA, Oates TW. A prospective multicenter 5-year
radiographic evaluation of crestal bone levels over time in 596 dental implants placed in 192 patients. J
A total of 596 solid screw or hollow cylinder TPS surfaced implants placed in 192 patients were evaluated
radiographically at implant placement, prosthesis placement, after 6 months and each year up to 5 years.
Significant remodeling was observed in the first 6 months (mean bone loss of 2.44 ± 1.20 mm). Mean bone
loss from prosthesis placement to 1 year and from 1 year to 5 years was 0.22 ± 0.42 mm and 0.18 ± 0.88
mm, respectively; 86% of the total bone loss over 5 years occurred by the time of prosthesis placement. The
observed trends were the same when adjusted for implant design, implant length and type of restoration.
There is therefore significant bone remodeling up to the time of final prosthesis placement, but minimal bone
López R, Frydenberg M, Baelum V. Clinical features of early periodontitis. J Periodontol 2009;80(5):749-758.
This study evaluated 87 cases of periodontitis with CAL ≥ 3 mm in at least two teeth, as well as 73 cases
without periodontitis. Periodontitis cases had more supragingival plaque, supragingival calculus and bleeding
on probing, but patterns of periodontal destruction were similar in cases and non-cases. There were positive
site-specific associations between determinants of supragingival plaque and calculus, bleeding on probing
and signs of periodontal destruction. Early cases of severe periodontitis therefore do not seem to have a
particular intraoral breakdown pattern.
Journal of Prosthetic Dentistry Vol. 101 No. 6 (June 2009)
Kinsel RP, Lin D. Retrospective analysis of porcelain failures of metal ceramic crowns and fixed partial
dentures supported by 729 implants in 152 patients: patient-specific and implant-specific predictors of
ceramic failure. J Prosthet Dent 2009;101(6):388-394.
Data from 152 patients with 390 single crowns and 94 FPDs (a total of 998 dental units) supported by a total
of 729 implants were collected. Porcelain fractures (94 dental units) were significantly associated with
opposing metal-ceramic restorations on implants, bruxism and lack of a protective occlusal device. The risk
of porcelain fracture was 7-fold higher, and the risk of fracture requiring repair or replacement was 13-fold
higher, when metal-ceramic prostheses opposed another implant-supported restoration. With bruxism, the
risk of fracture was 7-fold greater, and lack of a protective occlusal device increased the risk 2-fold.
Journal of Prosthodontics Vol. 18 No. 4 (June 2009)
Tsolaki IN, Madianos PN, Vrotsos JA. Outcomes of dental implants in osteoporotic patients. A literature
review. J Prosthodont 2009;18(4):309-323.
A literature search was performed for papers relating to dental implant outcomes in osteoporosis. A total of
39 non-review articles were identified and reviewed. Lower osseointegration in osteoporotic/osteopenic bone
compared to normal bone was observed in 13/16 animal studies. Two thirds of clinical reports mentioned
success and three quarters of human studies supported the applicability of implants in osteoporotic patients.
The use of implants was not contraindicated in osteoporotic patients, but an amended surgical technique and
longer healing may be necessary. However, data are limited and larger prospective studies are required.