Long-term outcomes of osteotome sinus floor elevation with or without bone grafting: The 10-year results of a randomized controlled trial.

AIMS: To assess the long-term clinical and radiographic results of implants placed using osteotome sinus floor elevation (OSFE) with or without bone grafting. MATERIALS AND METHODS: Forty-five patients were randomly assigned into two groups: Group 1 (OSFE with deproteinized bovine bone mineral) and Group 2 (OSFE without grafting). The patients were recalled at 1, 3, 5 and 10 years after surgery. The implant survival, endo-sinus bone gain (ESBG), marginal bone loss (MBL), peri-implant bone height (PBH, distance from the most coronal level to the most apical level of bone-to-implant contact), prosthesis survival and hardware complications, and peri-implant soft tissue conditions were assessed. RESULTS: Forty patients attended the 10-year examination. Mean residual bone height was 4.58 ± 1.28 mm. The 10-year cumulative survival rate was 90.7% for Group 1 and 95.0% for Group 2. The PBH was 5.89 ± 1.24 mm for Group 1 and 5.74 ± 1.43 mm for Group 2 at 10 years. The ESBG of both groups remained stable after 3 years. Two-thirds of the implants were free of hardware complications. No significant differences in MBL and peri-implant tissue parameters were found. CONCLUSION: OSFE with or without grafting both yielded predictable clinical outcomes with similar PBH (ClinicalTrials.gov. NCT01619956).

Endo-sinus bone formation after transalveolar sinus floor elevation without grafting with simultaneous implant placement: Histological and histomorphometric assessment in a dog model.

AIM: To evaluate endo-sinus new bone formation and implant osseointegration after transalveolar sinus floor elevation (TSFE) and simultaneous implant placement without any grafting materials and to investigate the influence of implant surface modification on bone healing process under this circumstance. MATERIALS AND METHODS: Transalveolar sinus floor elevation and simultaneous implant placement were conducted bilaterally on 12 Labrador dogs. No grafting materials were used during surgery. Implants with two different surfaces (SLA and SLActive) were placed in a split-mouth design. The animals were sacrificed 4, 8 and 24 weeks after surgery for histological and histomorphometric assessments. Bone-to-implant contact (BIC%), alveolar bone height (ABH) and the percentages of mineralized bone (MB%) in the area of interest were analysed. The probing depth (PD) and bleeding on probing (BOP) were also assessed to describe peri-implant health conditions. RESULTS: Sprouts of new bone in direct contact with implant surface were seen in the elevated area at every time point. Newly formed woven bone under sinus membrane was visible. SLActive implants exhibited favourable results compared with SLA implants regarding ABH at 4 weeks and BIC% at 4 and 8 weeks. Sites with BOP positive could be observed in both groups at any time point. No newly formed bone can be found on the implant apex with either SLA or SLActive surfaces at any time point. CONCLUSIONS: Spontaneous new bone formation from the parent bone walls could be observed after TFE without any grafting materials. No clear evidence of bone formation from the Schneiderian membrane could be found. Even though there were trends for quicker bone response of SLActive implants, this study failed to show the absolute advantage of SLActive in achieving endo-sinus bone formation.

Long-term outcomes of osteotome sinus floor elevation without bone grafts: a clinical retrospective study of 4-9 years.

OBJECTIVE: To evaluate the long-term clinical and radiographic outcomes of dental implant placed using osteotome sinus floor elevation (OSFE) without bone grafts, and to analyze the potential influence factors of implant survival and endo-sinus bone remodeling. MATERIAL AND METHODS: A retrospective study design was adopted. The clinical and radiographic data of 96 implants in 80 patients were collected after 4-9 (mean 5.40) years follow-up. Implant failures, peri-implant marginal bone loss (MBL), and endo-sinus bone remodeling on the radiographs were evaluated. A life-table analysis was used to assess the implant survival. Statistical models were established to investigate the potential influence factors of implant survival and endo-sinus bone gain (ESBG). RESULTS: In total, nine implants in seven patients failed, giving the 9-year cumulative survival rates of 90.6% and 91.3% for implant-based analysis and patient-based analysis, respectively. The mean MBL between implant installation and the 4- and 9-year follow-up visit was 0.46 ± 0.88 and 0.50 ± 1.69 mm, respectively. The average ESBG on radiographs was 2.95 ± 1.25 and 2.16 ± 1.13 mm at the 4- and 9-year follow-up. The final ESBG was found to be positively correlated to implant protrusion length after surgery without any other factors related. The implant survival rate was significantly lower in severe atrophic site (residual bone height <5 mm). CONCLUSION: Osteotome sinus floor elevation without bone grafts is a predictable treatment modality in the long run. But it should be used with caution when the initial bone height of the edentulous site is lower than 5 mm. The final endo-sinus bone height was found to be positively correlated to implant protrusion length measured on radiographs immediately after implant installation.

Periodontal and peri-implant microbiota in patients with healthy and inflamed periodontal and peri-implant tissues.

OBJECTIVE: To compare the prevalence and levels of six bacterial pathogens within the subgingival/submucosal microbiota at teeth versus implants with various clinical conditions. MATERIAL AND METHODS: Twenty-two Chinese were included. Four subgingival/submucosal sites were selected for microbiological sampling within each subject, that is, (1) healthy peri-implant tissues; (2) peri-implantitis [PPD ≥ 5 mm, presence of bleeding on probing (BOP) and confirmed radiographic bone loss]; (3) healthy gingiva; and (4) periodontitis (PPD ≥4 mm). Subgingival/submucosal plaque was sampled using paper points. Quantitative real-time polymerase chain reaction (q-PCR) was used to quantify six pathogens, including Porphyromonas gingivalis (P.g.), Treponema denticola (T.d.), Aggregatibacter actinomycetemcomitans (A.a.), Fusobacterium nucleatum (F.n.), Prevotella intermedia (P.i.), and Staphylococcus aureus (S.a.). Counts were log10-transformed. RESULTS: The most commonly detected species were S. a. and F. n., while A. a. and. P. i. had the lowest detection frequency. The detection frequencies of diseased tooth or implant sites for each of the six target species were either equal to or higher than the respective frequencies at the corresponding healthy sites. There were no statistically significant differences for any of the species or clinical sites (P > 0.05, Cochran's Q test). No statistically significant differences in the bacterial loads were found among the four clinical sites; with the exception of F. nucleatum. This was more abundant in periodontitis sites (P = 0.023, Friedman's 2-way anova). Both periodontal and peri-implant sites, irrespective of their health status, were revealed to harbor S. aureus cells. The log10-transformed loads of S. aureus were approximately 3.5 within each of the clinical sites (P = 0.232). This was the highest of the six species analyzed. CONCLUSIONS: Within the same subjects, putative periodontal pathogens were common to both periodontal and peri-implant sites irrespective of health status. The prevalence and levels of P. gingivalis and F. nucleatum were significantly associated with periodontitis, but not with peri-implantitis. A. actinomycetemcomitans was associated with both disease conditions, periodontitis and peri-implantitis, but not with either gingival or mucosal health.

Osteotome sinus floor elevation with and without grafting: an animal study in Labrador dogs.

AIM: To evaluate implant stability and histological outcomes after osteotome sinus floor elevation (OSFE) procedure, and to compare new bone formation and implant osseointegration with and without grafting. MATERIAL AND METHODS: OSFE with simultaneous implant placement was conducted bilaterally on 6 Labrador dogs. Twenty-four implants were placed. The right side sinus (Group 1) was grafted with biphasic calcium phosphate (BCP), whereas the left side (Group 2) was left without any grafting materials. The animals were euthanized 8 and 24 weeks after surgery for histological and histomorphometric assessment. Bone-to-implant contact (BIC%), alveolar bone height (ABH), bone density (BD) and grafting material density (GMD) were measured. The implant stability (ISQ) was assessed using resonance frequency analysis (RFA) at implant placement and 1, 2, 4, 8, 12, 24 weeks after surgery. RESULTS: Endo-sinus new bone with direct contact to implant surface were observed in two groups at both time points. ABH showed no difference between groups at both time points. BIC% and BD in Group 2 (40.05%, 35.90%) was higher than those in Group 1 (23.30%,25.59%) at 24 weeks. Significant shrinkage of grafting material was seen in Group 1. The GMD in Group 1 at 8 weeks was 24.35%, while it dropped to 19.90% at 24 weeks. The changing pattern of ISQ for both groups were similar. CONCLUSIONS: Spontaneous new bone formation and better bone-to-implant contact were found for OSFE without grafting. The grafting material application during OSFE procedure showed no advantages in histological results.

Osteotome sinus floor elevation with or without grafting: a 3-year randomized controlled clinical trial.

AIMS: To evaluate the clinical and radiographic results of dental implant placed using osteotome sinus floor elevation (OSFE) with and without simultaneous grafting. MATERIALS & METHODS: Forty-five patients were randomly assigned into two groups: Group1: OSFE with deproteinized bovine bone mineral (DBBM) mixed with autogenous bone chips, and Group2: OSFE without grafting. The endo-sinus bone gain (ESBG) was assessed on radiographs at 6, 12, 24, 36 months following surgery as primary outcome measurement. Implant survivals and marginal bone loss (MBL) were assessed as secondary outcome measurements. RESULTS: Twenty-one implants in Group1 and 20 implants in Group2 were analysed. The residual bone height (RBH) was 4.63 ± 1.31 mm in average (4.67 ± 1.18 mm for Group1 and 4.58 ± 1.47 mm for Group2). The 3-year cumulative survival rates of implants were 95.2% for Group1 and 95.0% for Group2. The ESBG in Group1 reduced from 5.66 ± 0.99 mm at 6 months to 3.17 ± 1.95 mm at 36 months, whereas the ESBG in Group2 increased from 2.06 ± 1.01 mm at 6 months to 3.07 ± 1.68 mm at 36 months. The MBL after 3 years was 1.33 ± 0.46 mm in Group1 and 1.38 ± 0.23 mm in Group2. CONCLUSIONS: OSFE and simultaneous implant installation with and without grafting both resulted in predictable results. The application of grafting materials has no significant advantage in terms of clinical success.

Long-term outcomes of short dental implants supporting single crowns in posterior region: a clinical retrospective study of 5-10 years.

OBJECTIVE: Aimed to evaluate the long-term clinical and radiographic outcomes of short implants supporting single crowns in the posterior regions. MATERIAL AND METHODS: A retrospective study design was adopted. The clinical and radiographic data of 231 short implants (intra-bony length ≤8 mm) supporting single crowns in 168 patients, were collected after 5-10 (mean 7.22) years' follow-up. Implant and prosthesis failures, peri-implant marginal bone loss, biological and technical complications were evaluated. The influence factors on implant failure were studied. RESULTS: In total 4 implants and 11 prostheses failed. The 10-year (5-year) cumulative survival rate was 98.3% (98.7%) for implant-based analysis and 97.6% (98.2%) for patient-based analysis. The short implants placed in type IV bone yielded more failures than in type I-III and presented a survival rate of 94.0%. The 10-year survival rate of the prostheses was 95.2%. The mean marginal bone loss between implant installation and the 10 years' follow-up visit was 0.63 ± 0.68 mm. The marginal bone loss between the first and 5th year was minimal (0.05 ± 0.10mm and not statistically significant). 18 (7.8%) implants were exposed to biological complications, whereas 29 (12.6%) implants were involved in technical complications. CONCLUSIONS: High survival rates for both the implants and the prostheses could be achieved after 5-10 years for short implants supporting single crowns, without severe marginal bone loss and complications. One may conclude that a single crown supported by a short implant is a predictable treatment modality. However, short implants in type IV bone sites should be applied with caution.

The roles of PI3K/Akt signaling pathway in regulating MC3T3-E1 preosteoblast proliferation and differentiation on SLA and SLActive titanium surfaces.

Chemical modification to produce a hydrophilic microrough titanium (Ti) implant surface has been shown to increase osseointegration compared with microrough topography alone. This study aimed to investigate the roles of PI3K/Akt signaling pathway in regulating proliferation and differentiation of osteoblasts in response to surface microroughness and hydrophilicity. Ti disks were manufactured to present different surface morphologies: a smooth pretreatment surface (PT), a rough hydrophobic surface that was sand-blasted, large-grit, acid-etched (SLA), and an SLA surface with the same roughness that was chemically modified to possess high wettability/hydrophilicity (SLActive/modSLA). MC3T3-E1 cells were cultured on these substrates with or without LY294002, a PI3K inhibitor, and their behaviors, including cell viability (MTT colorimetric assay), alkaline phosphatase (ALP) activity, and osteogenic genes expression of osteopontin (OPN) and osteocalcin (OCN) were measured. Western blot was applied to detect the expression of PI3K/Akt signal pathway proteins. The results showed that a decrease in osteoblast proliferation associated with the Ti surfaces (SLActive > SLA > PT) correlated with an increase in activity of the osteogenic differentiation markers ALP. The peak of ALP activity appeared earlier at 7 days for the SLActive surfaces compared with the SLA and PT surfaces. Osteoblast proliferation, as well as the level of p-Akt, was significantly inhibited by LY294002 in all three Ti surfaces. The top value of ALP activity was increased with the inhibition of PI3K/Akt signaling pathway while the time of the peak appeared was not advanced. The expression levels of OPN and OCN were upregulated by the effect of surface roughness and hydrophilicity, which were further enhanced by LY294002. In conclusion, osteogenic responses to SLActive surface were moderately better than the SLA surface and protein expression studies indicated that PI3K/Akt signaling activation may be responsible for this increased osteogenic differentiation. Surface microroughness and hydrophilicity may affect osteoblast functions by targeting osteoblast proliferation and the early stage of osteoblast differentiation through PI3K/Akt signaling pathway.

[Papilla alteration in different gingival biotypes at single implant-supported restoration in anterior maxilla].

PURPOSE: To observe the alteration of the interproximal papilla height after single implant restoration in the anterior maxilla and to assess the influence of gingival biotypes on papilla regeneration. METHODS: Thirty patients with single-tooth implant-supported restorations in the anterior maxilla were assigned to two groups according to labial mucosa thickness. Group A: labial mucosal thickness≥1.5 mm and group B: labial mucosal thickness<1.5 mm. The presence of interproximal papilla as well as the distance between papilla apex and contact point were assessed at crown attachment (baseline) and after 6 months (follow-up).Statistical analysis was performed using SPSS19.0 software package. RESULTS: The 6-month survival rate of implants was 100%. The mean height of interproximal papilla at baseline and follow-up was (1.64±0.97) mm and (3.10±1.39) mm, respectively. A significant improvement in papilla height was found between baseline and follow-up(P<0.05). In group A, the mean distance from papilla apex to the contact point at mesial and distal aspects was (0.15±0.24) mm and (0.23±0.33) mm, respectively, and the presence of interproximal papilla were (97±5)% and (94±8)%, respectively. In group B, the mean distance from papilla apex to the contact point at mesial and distal aspects was (1.94±0.40) mm and (2.10±0.34) mm, respectively, and the presence of interproximal papilla was (53±9)% and (43±14)% respectively. Statistically significant difference was found between the two groups(P<0.05). CONCLUSIONS: The interproximal papilla height around single implant restorations could improve significantly after 6-month follow-up. The interproximal papilla height around single-tooth implants in the anterior maxilla was influenced by gingival biotype. The regenerative potential of thick-gingival biotype was better than that of thin-gingival biotype.

Characterization and preosteoblastic behavior of hydroxyapatite-deposited nanotube surface of titanium prepared by anodization coupled with alternative immersion method.

The modification on the titanium (Ti) implant surface is an effective method to improve the bioactivity of Ti. In this study, a hydroxyapatite (HA)-deposited nanotubular Ti surface was prepared by anodization coupled with an alternative immersion method (AIM). Surface physicochemical characteristics including morphology, microstructure, composition, roughness were evaluated by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Preosteoblast cell (MC3T3-E1) behavior on the HA-deposited nanotube surface, including cell morphology, proliferation, alkaline phosphatase (ALP) activity, osteocalcin secretion, and mineralization, were also investigated. The untreated nanotube surface and bare Ti were used as controls. The results showed that synthetic HA crystals could be efficiently grown on/inside the nanotubes after AIM treatment in saturated Ca(OH)(2) and 0.02M (NH(4))(2) HPO(4). The amount of synthetic HA on nanotube layer was dependent on the number of dipping cycles. Significant increases in ALP activity and osteocalcin production on day 7 and 14 and calcium deposition on day 21 (P < 0.05) were observed for HA-deposited nanotubular Ti surface when compared with untreated nanotube layer and bare Ti. However, the cell proliferation rate on HA-deposited nanotube surfaces was slowed down significantly (P < 0.05). All these results indicated that this HA-deposited nanotube surface might have the potential benefit to enhance implant osseointegration. The synthetic HA TiO(2) nanotube loading might be a highly promising path to improve the bioactivity of Ti-based implants.

Papillae alterations around single-implant restorations in the anterior maxillae: thick versus thin mucosa.

To evaluate the papilla alterations around single-implant restorations in the anterior maxillae after crown attachment and to study the influence of soft tissue thickness on the papilla fill alteration. According to the inclusion criteria, 32 patients subjected to implant-supported single-tooth restorations in anterior maxillae were included. The patients were assigned to two groups according to the mucosal thickness: (i) group 1, 1.5 mm s mucosal thickness 3 mm; and (ii) group 2, 3 mm

The roles of extracellular signal-regulated kinase 1/2 pathway in regulating osteogenic differentiation of murine preosteoblasts MC3T3-E1 cells on roughened titanium surfaces.

Surface roughness of titanium-based implants may enhance osteogenic differentiation of cells in vitro and bone-to-implant contact in vivo. Nevertheless, how surface roughness regulates the signaling pathway of osteoblasts is little understood. The study intended to investigate specifically the roles of extracellular signal-regulated kinase 1/2 (ERK1/2) pathway in regulating osteogenic differentiation of MC3T3-E1 murine preosteoblast cells on Ti surfaces. Substrates applied were two groups of titanium disks: (1) sand-blasted and acid-etched rough surfaces (SLA) and (2) smooth pretreated Ti surfaces (PT). Surface morphology of the two groups was examined by scanning electron microscope, and cell morphology cultured on Ti disks was observed by confocal microscope. The levels of alkaline phosphatase (ALP) activity and calcium deposition were measured and compared between the two groups. Real-time polymerase chain reaction was applied to detect the expression levels of osteogenic genes including runt related protein 2 (Runx2), osterix (OSX), osteocalcin (OCN) and osteoprotegerin (OPN) of the cells cultured on the two groups of substrates and on SLA surfaces treated with ERK1/2 inhibitor, PD98095. ERK1/2 activities in MC3T3-T1 cells were measured by Western-blotting on the two surfaces with or without PD98095. Cells cultured on rougher SLA surfaces displayed a more differentiated morphology. ALP activities at 7 days and 14 days and the calcium deposition at 28 days were significantly higher on SLA surfaces. The expression levels of Runx2, OSX, OPN and OCN were upregulated by the effect of surface roughness and PD98095 further upregulated the expression levels of these osteogenic genes on SLA surfaces. ERK1/2 phosphorylation was continuously inhibited by surface roughness at 2 days, 4 days and 6 days. In contrast, no marked alterations in ERK1/2 phosphorylation on PT surfaces were observed. PT surfaces treated with PD98095 (50 µM) and SLA surfaces without PD98095 both demonstrated reduced ERK1/2 phosphorylation of the cells, and the inhibitive effect of SLA surfaces was milder than that of PD98095. In conclusion, ERK1/2 pathway may be a negative regulator of cell differentiation in a dosage-dependent manner, and the enhancing effect of surface roughness on osteoblastic differentiation may be mediated through inhibiting ERK1/2 pathway.