Accuracy of robotic surgery for dental implant placement: A systematic review and meta-analysis.

OBJECTIVES: To systematically analyze the accuracy of robotic surgery for dental implant placement. MATERIALS AND METHODS: PubMed, Embase, and Cochrane CENTRAL were searched on October 25, 2023. Model studies or clinical studies reporting the accuracy of robotic surgery for dental implant placement among patients with missing or hopeless teeth were included. Risks of bias in clinical studies were assessed. Meta-analyses were undertaken. RESULTS: Data from 8 clinical studies reporting on 109 patients and 242 implants and 13 preclinical studies were included. Positional accuracy was measured by comparing the implant plan in presurgery CBCT and the actual implant position in postsurgery CBCT. For clinical studies, the pooled (95% confidence interval) platform deviation, apex deviation, and angular deviation were 0.68 (0.57, 0.79) mm, 0.67 (0.58, 0.75) mm, and 1.69 (1.25, 2.12)°, respectively. There was no statistically significant difference between the accuracy of implants placed in partially or fully edentulous patients. For model studies, the pooled platform deviation, apex deviation, and angular deviation were 0.72 (0.58, 0.86) mm, 0.90 (0.74, 1.06) mm, and 1.46 (1.22, 1.70)°, respectively. No adverse event was reported. CONCLUSION: Within the limitation of the present systematic review, robotic surgery for dental implant placement showed suitable implant positional accuracy and had no reported obvious harm. Both robotic systems and clinical studies on robotic surgery for dental implant placement should be further developed.

Accuracy and safety of a haptic operated and machine vision controlled collaborative robot for dental implant placement: A translational study.

OBJECTIVES: Multiple generations of medical robots have revolutionized surgery. Their application to dental implants is still in its infancy. Co-operating robots (cobots) have great potential to improve the accuracy of implant placement, overcoming the limitations of static and dynamic navigation. This study reports the accuracy of robot-assisted dental implant placement in a preclinical model and further applies the robotic system in a clinical case series. MATERIALS AND METHODS: In model analyses, the use of a lock-on structure at robot arm-handpiece was tested in resin arch models. In a clinical case series, patients with single missing teeth or edentulous arch were included. Robot-assisted implant placement was performed. Surgery time was recorded. Implant platform deviation, apex deviation, and angular deviation were measured. Factors influencing implant accuracy were analyzed. RESULTS: The in vitro results showed that with a lock-on structure, the mean (SD) of platform deviation, apex deviation, and angular deviation were 0.37 (0.14) mm, 0.44 (0.17) mm, and 0.75 (0.29)°, respectively. Twenty-one patients (28 implants) were included in the clinical case series, 2 with arches and 19 with single missing teeth. The median surgery time for single missing teeth was 23 (IQ range 20-25) min. The surgery time for the two edentulous arches was 47 and 70 min. The mean (SD) of platform deviation, apex deviation, and angular deviation was 0.54 (0.17) mm, 0.54 (0.11) mm, and 0.79 (0.22)° for single missing teeth and for 0.53 (0.17) mm, 0.58 (0.17) mm, and 0.77 (0.26)° for an edentulous arch. Implants placed in the mandible had significantly larger apex deviation than those in the maxilla. CONCLUSION: Cobot-assisted dental implant placement showed excellent positional accuracy and safety in both the in vitro study and the clinical case series. More technological development and clinical research are needed to support the introduction of robotic surgery in oral implantology. Trial registered in ChiCTR2100050885.

Accuracy and primary stability of tapered or straight implants placed into fresh extraction socket using dynamic navigation: a randomized controlled clinical trial.

OBJECTIVES: To compare the accuracy and primary stability of tapered and straight implants undergoing immediate implant placement with dynamic navigation. MATERIALS AND METHODS: Patients with compromised anterior teeth in maxilla were recruited and allocated randomly into (1) tapered implant group (TI group) and (2) straight implant group (SI group). Implants were inserted into fresh sockets with dynamic navigation. Three-dimensional platform deviation, apex deviation, angular deviation, insertion torque value (ITV) and implant stability quotient (ISQ) were recorded. RESULTS: Twenty patients with 20 implants were included. The overall platform, apex, and angular deviation were 0.87 ± 0.35 mm, 0.81 ± 0.34 mm, and 2.40 ± 1.31°, respectively. The accuracy was 0.86 ± 0.26 mm, 0.76 ± 0.33 mm, and 2.49 ± 1.54° for TI, and 0.89 ± 0.44 mm, 0.88 ± 0.36 mm, and 2.31 ± 1.01° for SI, with no significant difference (p = 0.85, 0.45, 0.76). Sagittal root position classification (SRP) class I may obtain greater error in numerical values in straight implants (0.97 ± 0.47 mm vs. 0.6 ± 0.16 mm, 0.92 ± 0.36 mm vs. 0.73 ± 0.36 mm, 2.48 ± 1.19° vs. 1.71 ± 0.14°). The overall ISQ was 60.74. ISQ was 60.48 for TI and 60.96 for SI, with no significant difference. Acceptable ITV (> 15 Ncm) was achieved in most of the included patients (SI 7/10, TI 9/10). CONCLUSIONS: High accuracy and primary stability of immediate implant placement could be achieved both in tapered and straight implants with dynamic navigation systems. CLINICAL RELEVANCE: Tapered and straight implants did not reach a consensus on which was better in immediate implant regarding to accuracy and primary stability. Our study demonstrated implant macrodesign did not affect accuracy and primary stability in immediate implant using dynamic navigation.

Clinical, radiographic and economic evaluation of short-6-mm implants and longer implants combined with osteotome sinus floor elevation in moderately atrophic maxillae: A 3-year randomized clinical trial.

AIM: To compare the 3-year clinical, radiographic and economic outcomes of short-6-mm implants and longer implants combined with osteotome sinus floor elevation (OSFE) in the posterior maxilla. MATERIAL AND METHODS: This study enrolled 225 patients (225 implants with diameter of 4.1 mm and 4.8 mm) with a posterior maxillary residual bone height (RBH) of 6-8 mm. Patients were randomly divided into three groups: Group 1 (6 mm implants alone), Group 2 (8 mm implants + OSFE) and Group 3 (10 mm implants + OSFE). The following outcomes were recorded at 1 and 3-year examinations: implant survival, probing pocket depth (PPD), bleeding on probing (BOP), modified plaque index (mPI), marginal bone loss (MBL), biological and technical complications, complication-free survival and treatment costs. RESULTS: At the 3-year follow-up, 199 patients (Group 1: 67; Group 2: 62; Group 3: 70) were re-examined. Implant survival rates were 91.80%, 97.08% and 100.00% in groups 1, 2 and 3. Implant survival rate in Group 1 was significantly lower than that in Group 3 (p = 0.029). A multivariate Cox model showed that the short-6-mm implants with wide diameter had a protective effect on implant survival (hazard ratio: 0.59, p = 0.001). No significant differences in BOP%, PPD, mPI, MBL and complication-free survival rate were found among the three groups. The average costs of retreatment were 8.31%, 1.96% and 0.56% of the total costs in groups 1, 2 and 3. The cost to avoid a 1% increase in implant loss associated with 6-mm implants over a 3-year period was 369 CNY (56 USD) using a 10-mm implant with OSFE and 484 CNY (74 USD) using an 8-mm implant with OSFE. CONCLUSION: In the moderately atrophic posterior maxillae, the three treatments showed acceptable clinical, radiographic and economic outcomes with up to 3-year follow-up. 10-mm implants combined with OSFE showed more favourable implant survival and fewer maintenance costs in comparison with short-6-mm implants, which were less expensive.

Oral microbial profile variation during canine ligature-induced peri-implantitis development.

BACKGROUND: Dental implants have become well-established in oral rehabilitation for fully or partially edentulous patients. However, peri-implantitis often leads to the failure of dental implants. The aim of this study was to understand the core microbiome associated with peri-implantitis and evaluate potential peri-implantitis pathogens based on canine peri-implantitis model. RESULTS: In this study, three beagle dogs were used to build peri-implantitis models with ligature-induced strategy. The peri-implant sulcular fluids were collected at four different phases based on disease severity during the peri-implantitis development. Microbial compositions during peri-implantitis development were monitored and evaluated. The microbes were presented with operational taxonomic unit (OTU) classified at 97% identity of the high-throughput 16S rRNA gene fragments. Microbial diversity and richness varied during peri-implantitis. At the phylum-level, Firmicutes decreased and Bacteroides increased during peri-implantitis development. At the genus-level, Peptostreptococcus decreased and Porphyromonas increased, suggesting peri-implantitis pathogens might be assigned to these two genera. Further species-level and co-occurrence network analyses identified several potential keystone species during peri-implantitis development, and some OTUs were potential peri-implantitis pathogens. CONCLUSION: In summary, canine peri-implantitis models help to identify several potential keystone peri-implantitis associated species. The canine model can give insight into human peri-implantitis associated microbiota.

Long-term outcomes of osteotome sinus floor elevation without grafting in severely atrophic maxilla: A 10-year prospective study.

OBJECTIVE: The aim of the present study was to report 10-year results of osteotome sinus floor elevation (OSFE) without grafting severely atrophic maxilla (residual bone height ≤4 mm). MATERIALS AND METHODS: Patients undergoing OSFE without grafting and implant placement were included for 10-year examinations. Implant survival, complication-free survival, modified bleeding index (mBI), modified plaque index (mPI), pocket probing depth (PPD), peri-implant marginal bone loss (MBL), endo-sinus bone gain (ESBG) and mean cost of recurrence were evaluated. RESULTS: Overall, 23 patients with 35 implants attended 10-year examination. Cemented implant crowns or implant-supported fixed dental prostheses were delivered to the patients. Kaplan-Meier implant survival was 89.2% at implant level and 84.1% at patient level. Complication-free survival was 26.0% at patient level and 37.0% at implant level. The average complication-free survival time was 74.6 months (95% CI: 63.2-86.0 months) at implant level and 69.1 months (95% CI: 54.8-83.4 months) at patient level. The mBI, mPI, PPD, MBL and ESBG at 10-year follow-up were 0.91 ± 0.58, 0.48 ± 0.51, 2.94 ± 0.79 mm, 1.63 ± 0.83 mm and 2.72 ± 0.51 mm, respectively. The cost of managing recurrence was 43.6% of the initial cost of treatment. CONCLUSION: The results of the present study indicate that OSFE without grafting is a reliable treatment option in severely atrophic maxilla. Acceptable survival rate, stable MBL and ESBG could be achieved within 10 years. Low complication-free survival and high costs of recurrence management need to be considered.

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).

Short versus longer implants with osteotome sinus floor elevation for moderately atrophic posterior maxillae: A 1-year randomized clinical trial.

PURPOSE: To compare the clinical, radiographic outcomes and patient satisfaction of short-6-mm implants and longer implants combined with osteotome sinus floor elevation (OSFE). MATERIALS AND METHODS: Two hundred and twenty-five patients with 225 implants were included and randomly assigned into three groups (each group: 75 implants) using randomizing table method: group 6 mm (6 mm implants alone), group 8 mm + O (8 mm implants + OSFE) and group 10 mm + O (10 mm implants + OSFE). Outcomes measures were as follows: implant survival, complication, resonance frequency analysis measurement, surgical time, bleeding on probing (BOP), pocket probing depth (PPD), modified plaque index (mPI), marginal bone loss (MBL) and patient satisfaction. RESULTS: The dropout rate was 3.6% at 1 year. Implant survival rates were 96%, 100% and 100% in group 6 mm, group 8 mm + O and group 10 mm + O, respectively. In group 6 mm, the survival rates of implants with diameter of 4.1 mm were 90% (27/30), while the survival rates of implants with diameter of 4.8 mm were 100% (42/42). The surgical time (min) in group 6 mm was significantly shorter than those in group 8 mm + O and group 10 mm + O (13.6 ± 2.2, 19.4 ± 3.7 and 18.3 ± 4.3, respectively, p = 0.03). No significant differences in ISQ values, BOP, PPD, mPI and MBL were found among three groups. Significant higher value of intra-operative discomfort was found in group 6 mm (p = 0.02). CONCLUSION: All treatment options provided acceptable clinical and radiographic results up to 1 year after loading. The current 1-year results must be confirmed by longer follow-ups of at least 5 years.

A novel semiautomatic segmentation protocol to evaluate guided bone regeneration outcomes: A pilot randomized, controlled clinical trial.

OBJECTIVES: The aims of this study were to (a) present a novel morphological contour interpolation (MCI) algorithm based method to evaluate grafted bone alterations following guided bone regeneration (GBR), (b) compare clinical and radiological outcomes of GBR with two different collagen membranes. MATERIALS AND METHODS: The data were retrieved from an ongoing randomized controlled trial. Patients were randomly allocated into two groups: (a) control group (CG): Bio-Gide (b) test group (TG): bovine dermis-derived collagen membrane. Cone beam computed tomography examinations were performed 1 week (T0) and 6 months after surgery (T1). PES/WES at T1, grafted bone volume and density changes from T0 to T1 were recorded. RESULTS: Thirty-six patients (16/20 in test/control group, respectively) were enrolled in the present study. Excellent inter-observer reliability (ICC ≥ 0.97) was revealed for repeated measurements using this method. Significant volumetric reduction of grafted bone were found in both groups (test group: from 0.60 to 0.39 cm3 , p < 0.01; control group: from 0.54 to 0.31 cm3 , p < 0.01). Mean bone density (gray-scale values) significantly increased from 305.12 to 456.69 in CG (p < 0.01). In TG, it slightly increased from 304.75 to 393.27 (p = 0.25). The mean PES/WES values were 13.84 (6.62/7.22) and 13.90 (6.70/7.20) for TG and CG, respectively. As for inter-group comparison, no significant differences of grafted bone volume change, density change and PES/WES were found between two groups. CONCLUSION: Within the limitations of this study, the novel MCI-based method is a reproducible tool to segment and visualize changes of grafted bone in 3D. Furthermore, both collagen membranes could be used as a barrier membrane for GBR in humans.

Long-term outcomes of narrow diameter implants in posterior jaws: A retrospective study with at least 8-year follow-up.

OBJECTIVE: The aim of this study was to evaluate the long-term survival, complications, peri-implant conditions, marginal bone loss, and patient satisfaction of fixed dental prostheses supported by narrow diameter implants (NDIs) in the posterior jaws. MATERIALS AND METHODS: This study was designed as a retrospective cohort study with a mean follow-up time of 10.1 years (SD: 2.5 years). Patients receiving NDIs in posterior jaw were reviewed. Implant survival, hardware complication, modified plaque index (mPI), peri-implant probing depth (PPD), percentage of bleeding on probing (BOP%), marginal bone loss (MBL), and patient satisfaction were evaluated. Log-rank test and t test were used to detect the influence of implant location and restoration type. RESULTS: Sixty-seven patients with 98 NDIs (Premolar site: 81, Molar site: 17, Single crowns: 33, Splinted restorations: 65) were included. The overall implant survival rates were 96.9% at implant level and 97.0% at patient level. Veneer chipping was the most common hardware complication. The veneer chipping rates were 19.4% at patient level and 18.4% at implant level. All patients showed acceptable oral hygiene. Thus, the average MBL was 1.19 mm at implant level and 1.15 mm at patient level. Eight implants (8.5%) and six patients (9.2%) were diagnosed with peri-implantitis. Fifty-eight patients (89.2%) were satisfied with the esthetics of the restorations, while 55 patients (84.6%) were satisfied with the function of the restorations. CONCLUSION: Narrow diameter implants could be a predictable treatment option in the long term. High survival rates, high patient satisfaction, acceptable complication rates and marginal bone loss could be achieved. Further long-term studies are needed to evaluate the predictability of NDIs in molar sites.

Hardware complications and failure of three-unit zirconia-based and porcelain-fused-metal implant-supported fixed dental prostheses: a retrospective cohort study with up to 8 years.

OBJECTIVE: The aim of the present study was to assess the hardware complications and survival of three-unit implant-supported zirconia-based fixed dental prostheses (IZ) and implant-supported porcelain-fused-metal fixed dental prostheses (IP). MATERIAL AND METHODS: The study is a retrospective cohort study with up to 8 years (mean 4.8 years) follow-up. Patients with conventional three-unit implant-supported fixed dental prostheses (without cantilever) in posterior area were reviewed. Hardware complications and survival rate were evaluated. Chi-Square test was used to test the difference between IZ and IP groups. RESULTS: Two hundred and thirty-seven patents (IZ : 112, IP : 125) with 279 three-unit restorations (IZ : 127, IP : 152) participated in the study. The overall survival rate was 95.3% in IZ group and 94.7% in IP group at implant-level and 94.6% in IZ group and 94.4% in IP group at subject-level. Veneer chipping was the most frequently seen complication (20.1%). Significant higher minor veneer chipping rate (Grade 1) was found in IZ group (P = 0.04). No significant difference of veneer chipping rate (Grade 2 and Grade 3) was found between the two groups. The overall hardware complication rates of IZ were significantly higher than IP (33.07% and 18.42%, P = 0.01). CONCLUSION: High survival rate of zirconia-base and Porcelain-fused-to-metal (PFM) restorations can be achieved with up to 8 years follow-up. The zirconia-based restorations need more polishing procedures, maintenance, and professional care than PFM restorations. The number of implants supporting a fixed dental prosthesis did not influence the implant survival and hardware complications. Well-designed studies with high evidence level are still needed to further explore the hardware complications and clinical survival of IZ and IP.

Resonance frequency analysis of implants placed with osteotome sinus floor elevation in posterior maxillae.

OBJECTIVES: To test the reliability and validity of implant stability quotient (ISQ) values used for assessment of the condition of bone-to-implant interface in the osteotome sinus floor elevation (OSFE) model and to evaluate the influence of residual bone height (RBH) on ISQ values. MATERIAL AND METHODS: Forty-six Straumann(®) tissue-level SLA implants (Φ4.8 mm*8 mm, wide neck, standard plus) placed in 39 patients applying OSFE without grafting were included in the study. Patients were assigned to three groups based on the RBH with one implant per patient randomly chosen: (1) 2 ≤ RBH < 4 mm (n = 14); (2) 4 ≤ RBH < 6 mm (n = 15); (3) 6 ≤ RBH < 8 mm (n = 10). ISQ values were determined with Osstell ISQ(®) at 0, 2, 4, 8, 12, 16, and 20 weeks postoperation. The reliability of RFA measurements was tested by the degree of dispersion of ISQ values at each time point, and the validity was tested by linear correlation between ISQ and RBH. ISQ values were then compared among groups at all observed time points. RESULTS: The implants achieved a mean ISQ value of 63.6 immediately after surgery and reached a higher ISQ level of 70 after 20 weeks with a dip at 4 weeks. A higher degree of dispersion of ISQ values was observed immediately after surgery compared to the other time points. No significant correlations were found between RBH and ISQ values and no significant difference in ISQ values among groups at all the time points. CONCLUSION: Within the limits of the study, it may be implied that ISQ values are not able to assess the condition of bone-to-implant interface and the role of single RFA measurement in determining loading protocol is questionable.

Evaluation of the clinical and aesthetic outcomes of Straumann(®) Standard Plus implants supported single crowns placed in non-augmented healed sites in the anterior maxilla: a 5-8 years retrospective study.

PURPOSE: To evaluate the long-term aesthetic outcome of the single crowns supported by soft tissue level implants placed in healed sites in the anterior maxilla region via the pink aesthetic score (PES) and the white aesthetic score (WES). MATERIAL AND METHODS: According to the inclusion criteria, patients who had received a single Straumann(®) Standard Plus implant in the anterior maxilla at the Shanghai 9th People's Hospital between 2005 and 2008 were invited for a re-examination based on a number of inclusion criteria and exclusion criteria. Clinical, radiographic and aesthetic outcomes (PES/WES) were assessed during their revisit at 5-8 years after crown placement. RESULTS: Forty-five patients were enrolled in the study. All 45 implants were successfully integrated and most of the implants did not show signs of peri-implant disease at the time of the assessment. The marginal bone resorption was 1.10 ± 0.92 mm. The mean total PES was 8.48 ± 2.62 at the baseline, 9.57 ± 2.37 at the 6-10 months revisit and 9.01 ± 2.45 at the 5-8 years follow-up. The scores of the mesial and distal papillae increased significantly between the baseline and 6-10 months follow-up, this improvement remained stable at the 5-8 years follow-up. The scores of soft tissue level, colour of the soft tissue, soft tissue texture and the alveolar process decreased significantly between the 6-10 months and 5-8 years revisits. The mean WES was 7.83 ± 1.60 at the baseline and 7.72 ± 1.43 at the 5-8 years revisit. There was no significant difference of the WES between the baseline and 5-8 years revisit. CONCLUSION: The possibility of spontaneous papillae regeneration after implant treatment and the long-term stability of the regenerated papillae were confirmed. However, recession of the facial soft tissue has been found. The incidence of the recession at thin biotype sites tended to be higher.

Esthetic outcome and alterations of soft tissue around single implant crowns: a 2-year prospective study.

OBJECTIVE: The aim of this prospective study was to assess the esthetic outcome and alterations of peri-implant soft tissue using tissue-level implants. Furthermore, the influencing factors, including grafting and gingival biotype, of esthetic outcome of peri-implant soft tissue were also evaluated. MATERIALS AND METHODS: Of 38 patients with single missing anterior tooth in maxilla were treated with a Straumann (®) Standard Plus SLA implant. Bone augmentation was performed in 24 patients. Follow-up was conducted at 12 and 24 months after definitive crowns placement. Esthetic outcome using the pink esthetic score/white esthetic score (PES/WES) and clinical parameters were evaluated. RESULTS: The mean PES/WES value at baseline, 1-year, and 2-year examination was 13.79, 14.87, and 14.96. Significant improvement was found between baseline and 1-year examination (P < 0.01). And the improvement between 1-year and 2-year examination was not significant (P = 0.40). The mean PES changing value in patients with thick biotype was significantly higher than those with thin biotype at 2-year after definitive crowns placement (P = 0.03). Graft procedure had an unfavorable effect on mean PES value both at baseline and at follow-up (P < 0.01). No implants were lost at 2-year examination. Three patients experienced peri-implant infection. No significant difference was found with the passage of time in modified plaque index (mPI), probing pocket depth (PPD), and modified bleeding index (mBI). CONCLUSION: According to the present prospective clinical study, it can be concluded that it is feasible to use tissue-level implant to support single crowns in esthetic area. Favorable short-term esthetic outcome and stability of soft tissue around single implant crowns can be expected in patients with or without graft. However, graft procedures might have an unfavorable effect on the esthetic outcome. Gingival biotype can be considered as prognostic factor for esthetic outcome. RCTs with long-term follow-up are needed to provide evidence for the long-term stability of peri-implant soft tissue using tissue-level implant systems.

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.

Esthetic outcome of single implant crowns following type 1 and type 3 implant placement: a systematic review.

OBJECTIVE: The aim of the current review was to systematically appraise the esthetic outcome of soft tissue around single implant crowns following type 1 and type 3 implants placement in published dental literature. MATERIALS AND METHODS: A PubMed, Embase, and the Cochrane Central Register of Controlled Trials search up to March 2013 was conducted for articles published in the dental literature and limited to human trials with no language restricted. Furthermore, the reference lists of related articles were systematically screened, and additional manual searches were also performed. The primary outcome was pink esthetics score (PES). RESULTS: The electronic search in the database of PubMed, Embase, and the Cohrane Central Register of Controlled Trials resulted in the identification of 463 titles. These titles were initially screened by the two independent reviewers for possible inclusion. Screening the abstracts and titles led to 28 articles for future full-text consideration. From these articles, 18 studies were excluded. Manual search identified one article. After quality assessment, eight studies were included in this review. This review showed that no significant difference of PES index could be found between type 1 and type 3 implant placement. CONCLUSION: According to the current evidence, short-term esthetic outcomes of peri-implant soft tissue did not show significant difference following type 1 and type 3 implants placement with well-selected patients. However, caution should be taken for clinicians to extrapolate this result to all types of patients, as more randomized clinical trials are needed for long-term soft-tissue esthetic outcome in patients with high esthetic risk following type 1 implant placement. PES frequency, peri-implant condition and other risk factors for peri-implantitis are recommended to be reported for future studies.

Effects of a hydroxyapatite-coated nanotube surface of titanium on MC3T3-E1 cells: an in vitro study.

PURPOSE: To compare the biological behavior of mouse osteoblast-like cells (MC3T3-E1) on hydroxyapatite (HA)-coated nanotube surface of titanium and plasma-sprayed HA (HA-PS)-coated titanium surface. MATERIALS AND METHODS: The HA-coated nanotube surface of titanium were fabricated by anodization coupled with alternative immersion method (AIM). MC3T3-E1 osteoblast cells cultured in vitro were seeded onto these different surfaces; their growth states were examined by a confocal laser scanning microscope; the proliferation behavior, alkaline phosphatase (ALP) activity, osteocalcin (OCN) secretion, and analysis of osteoblastic gene expressions were also compared in detail. RESULTS: Significant increases in ALP activity and OCN production on days 7 and 14 (P < 0.05) were observed for AIM-coated HA (HA-AIM) surfaces. However, cells cultured on HA-AIM-coated surfaces showed a delayed growth pattern. Real-time polymerase chain reaction analyses showed significantly higher relative mRNA expression levels of osteoblastic genes (runt-related protein 2, osterix, osteopontin, OCN) in cells cultured on the HA-AIM-coated nanotube surfaces as compared with cells cultured on the HA-PS and baer Ti surfaces. CONCLUSION: The current research showed that the HA-AIM-coated nanotubular Ti surfaces enhance osteoblast differentiation, which had the potential to further improve osseointegration.

Impact of surface chemical treatment in surgical regenerative treatment of ligature-induced peri-implantitis: A canine study.

BACKGROUND: Implant surface decontamination is a critical step in peri-implantitis treatment. The aim of this study was to assess the effect chemotherapeutic agents have on reosseointegration after treatment on ligature-inducted peri-implantitis. METHODS: Six male canines had 36 implants placed and ligatures were placed around them for 28 weeks to establish peri-implantitis. The peri-implant defects were randomly treated by 1 of 3 methods: 0.12% chlorhexidine (CHX test group), 1.5% sodium hypochlorite (NaOCl test group), or saline (Control group). Sites treated with NaOCl and CHX were grafted with autogenous bone, and all sites then either received a collagen membrane or not. Histology sections were obtained at 6 months postsurgery to assess percentage of reosseointegration. RESULTS: Thirty-five implants were analyzed (CHX: 13; NaOCl: 14; Control:8). NaOCl-treated sites demonstrated reosseointegration with direct bone-to-implant-contact on the previously contaminated surfaces (42% mean reosseointegration), which was significantly higher than Controls (p < 0.05). Correspondingly, clinical improvement was noted with a significant reduction in probing depth from 5.50 ± 1.24 mm at baseline to 4.46 ± 1.70 mm at 6-months postsurgery (p = 0.006). CHX-treated sites demonstrated a nonsignificant reosseointegration of 26% (p > 0.05); however, in the majority of cases, the new bone growth was at a distance from the implant surface without contact. Probing depths did not improve in the CHX group. The use of membrane did not influence reosseointegration or probing depths (all p > 0.05). CONCLUSION: Titanium implants with peri-implantitis have the capacity to reosseointegrate following regenerative surgery. However, treatment response is contingent upon the chemotherapeutic agent selection. Additional chemical treatment with 1.5% NaOCl lead to the most favorable results in terms of changes in defect depth and percentage of reosseointegration as compared to CHX, which may hinder reosseointegration.

Nerve Growth Factor-Preconditioned Mesenchymal Stem Cell-Derived Exosome-Functionalized 3D-Printed Hierarchical Porous Scaffolds with Neuro-Promotive Properties for Enhancing Innervated Bone Regeneration.

The essential role of the neural network in enhancing bone regeneration has often been overlooked in biomaterial design, leading to delayed or compromised bone healing. Engineered mesenchymal stem cells (MSCs)-derived exosomes are becoming increasingly recognized as potent cell-free agents for manipulating cellular behavior and improving therapeutic effectiveness. Herein, MSCs are stimulated with nerve growth factor (NGF) to regulate exosomal cargoes to improve neuro-promotive potential and facilitate innervated bone regeneration. In vitro cell experiments showed that the NGF-stimulated MSCs-derived exosomes (N-Exos) obviously improved the cellular function and neurotrophic effects of the neural cells, and consequently, the osteogenic potential of the osteo-reparative cells. Bioinformatic analysis by miRNA sequencing and pathway enrichment revealed that the beneficial effects of N-Exos may partly be ascribed to the NGF-elicited multicomponent exosomal miRNAs and the subsequent regulation and activation of the MAPK and PI3K-Akt signaling pathways. On this basis, N-Exos were delivered on the micropores of the 3D-printed hierarchical porous scaffold to accomplish the sustained release profile and extended bioavailability. In a rat model with a distal femoral defect, the N-Exos-functionalized hierarchical porous scaffold significantly induced neurovascular structure formation and innervated bone regeneration. This study provided a feasible strategy to modulate the functional cargoes of MSCs-derived exosomes to acquire desirable neuro-promotive and osteogenic potential. Furthermore, the developed N-Exos-functionalized hierarchical porous scaffold may represent a promising neurovascular-promotive bone reparative scaffold for clinical translation.

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.