OBJECTIVES: This study was performed to evaluate patterns of failure time after insertion, failure rate according to loading time after insertion, and the patterns of failure after loading. MATERIALS AND METHODS: A total of 331 mini-implants were classified into the non-failure group (NFG) and failure group (FG), which was divided into failed group before loading (FGB) and failed group after loading (FGA). Orthodontic force was applied to both the NFG and FGA. Failed mini-implants after insertion, ratio of FGA to NFG according to loading time after insertion, and failed mini-implants according to failed time after loading were analyzed. RESULTS: Percentages of failed mini-implants after insertion were 15.79%, 36.84%, 12.28%, and 10.53% at 4, 8, 12, and 16 weeks, respectively. Mini-implant failure demonstrated a peak from 4 to 5 weeks after insertion. The failure rates according to loading time after insertion were 13.56%, 8.97%, 11.32%, and 5.00% at 4, 8, 12, and 16 weeks, respectively. Percentages of failed mini-implants after loading were 13.79%, 24.14%, 20.69%, and 6.9% at 4, 8, 12, and 16 weeks, respectively. CONCLUSION: Mini-implant stability is typically acquired 12 to 16 weeks after insertion, and immediate loading can cause failure of the mini-implant. Failure after loading was observed during the first 12 weeks.
Dental Implants ; Immediate Dental Implant Loading ; Orthodontic Anchorage Procedures

Biomedical Research ; trends ; Dental Implants ; Esthetics, Dental ; Humans ; Immediate Dental Implant Loading

OBJECTIVE: This study aimed to evaluate the clinical effect of the socket-shield technique in the maxillary anterior region at one year after implant placement. METHODS: Ten patients with maxillary anterior teeth that cannot be reserved were enrolled. Implants were installed following the socket-shield technique and restored six months after the surgery. The thickness of the labial maxillary bone of the implant was compared before and one year after the surgery. At one year follow-up, the reten-tion rate of the implants, Jemt classification, and pink and white aesthetic scores were evaluated. Postoperative complications and patient satisfaction were also analyzed. RESULTS: One year after installation, the retention rate of the implant was 100%. The thickness of the maxillary bone at the neck, central, and root section of the implant reduced to (0.27±0.21), (0.19±0.20), and (0.28±0.29) mm, respectively, compared with the values immediately after the operation. The thickness of the labial maxillary bone at the three measurement points immediately after and one year after the operation was statistically significant (P<0.05). No significant difference (P>0.05) of the difference thickness between immediate and one year after operation at the three measurement points. The pink esthetic scores of the implant prosthesis was 9.10±0.54, and the white esthetic scores was 9.00±0.63. No complications were observed, and the patients had a high degree of satisfaction. CONCLUSIONS The socket-shield technique could provide acceptable treatment results but cannot completely avoid the reconstruction of the labial maxillary bone of the implants. The technique exhibits favo-rable short-term aesthetic result, but its long-term clinical effect and aesthetic problems need to be further studied.
Dental Implants, Single-Tooth ; Esthetics, Dental ; Humans ; Immediate Dental Implant Loading ; Maxilla ; Tooth Socket ; Treatment Outcome

PURPOSE: The purpose of this study was to investigate the effects of implant tilting and the loading direction on the displacement and micromotion (relative displacement between the implant and bone) of immediately loaded implants by in vitro experiments and finite element analysis (FEA). METHODS: Six artificial bone blocks were prepared. Six screw-type implants with a length of 10 mm and diameter of 4.3 mm were placed, with 3 positioned axially and 3 tilted. The tilted implants were 30° distally inclined to the axial implants. Vertical and mesiodistal oblique (45° angle) loads of 200 N were applied to the top of the abutment, and the abutment displacement was recorded. Nonlinear finite element models simulating the in vitro experiment were constructed, and the abutment displacement and micromotion were calculated. The data on the abutment displacement from in vitro experiments and FEA were compared, and the validity of the finite element model was evaluated. RESULTS: The abutment displacement was greater under oblique loading than under axial loading and greater for the tilted implants than for the axial implants. The in vitro and FEA results showed satisfactory consistency. The maximum micromotion was 2.8- to 4.1-fold higher under oblique loading than under vertical loading. The maximum micromotion values in the axial and tilted implants were very close under vertical loading. However, in the tilted implant model, the maximum micromotion was 38.7% less than in the axial implant model under oblique loading. The relationship between abutment displacement and micromotion varied according to the loading direction (vertical or oblique) as well as the implant insertion angle (axial or tilted). CONCLUSIONS: Tilted implants may have a lower maximum extent of micromotion than axial implants under mesiodistal oblique loading. The maximum micromotion values were strongly influenced by the loading direction. The maximum micromotion values did not reflect the abutment displacement values.
Dental Implants ; Finite Element Analysis* ; Immediate Dental Implant Loading ; In Vitro Techniques*

PURPOSE: In this study, a temporal abutment fixation screw, designed to fracture in a controlled way upon application of an occlusal force sufficient to produce critical micromotion was developed. The purpose of the screw was to protect the osseointegration of immediate loaded single implants. MATERIALS AND METHODS: Seven different screw prototypes were examined by fixing titanium abutments to 112 Mozo-Grau external hexagon implants (MG Osseous(R); Mozo-Grau, S.A., Valladolid, Spain). Fracture strength was tested at 30degrees in two subgroups per screw: one under dynamic loading and the other without prior dynamic loading. Dynamic loading was performed in a single-axis chewing simulator using 150,000 load cycles at 50 N. After normal distribution of obtained data was verified by Kolmogorov-Smirnov test, fracture resistance between samples submitted and not submitted to dynamic loading was compared by the use of Student's t-test. Comparison of fracture resistance among different screw designs was performed by the use of one-way analysis of variance. Confidence interval was set at 95%. RESULTS: Fractures occurred in all screws, allowing easy retrieval. Screw Prototypes 2, 5 and 6 failed during dynamic loading and exhibited statistically significant differences from the other prototypes. CONCLUSION: Prototypes 2, 5 and 6 may offer a useful protective mechanism during occlusal overload in immediate loaded implants.
Bite Force ; Dental Implants, Single-Tooth ; Immediate Dental Implant Loading ; Mastication ; Osseointegration* ; Titanium

PURPOSE: In this study, a temporal abutment fixation screw, designed to fracture in a controlled way upon application of an occlusal force sufficient to produce critical micromotion was developed. The purpose of the screw was to protect the osseointegration of immediate loaded single implants. MATERIALS AND METHODS: Seven different screw prototypes were examined by fixing titanium abutments to 112 Mozo-Grau external hexagon implants (MG Osseous(R); Mozo-Grau, S.A., Valladolid, Spain). Fracture strength was tested at 30degrees in two subgroups per screw: one under dynamic loading and the other without prior dynamic loading. Dynamic loading was performed in a single-axis chewing simulator using 150,000 load cycles at 50 N. After normal distribution of obtained data was verified by Kolmogorov-Smirnov test, fracture resistance between samples submitted and not submitted to dynamic loading was compared by the use of Student's t-test. Comparison of fracture resistance among different screw designs was performed by the use of one-way analysis of variance. Confidence interval was set at 95%. RESULTS: Fractures occurred in all screws, allowing easy retrieval. Screw Prototypes 2, 5 and 6 failed during dynamic loading and exhibited statistically significant differences from the other prototypes. CONCLUSION: Prototypes 2, 5 and 6 may offer a useful protective mechanism during occlusal overload in immediate loaded implants.
Bite Force ; Dental Implants, Single-Tooth ; Immediate Dental Implant Loading ; Mastication ; Osseointegration* ; Titanium

PURPOSE: The purpose of this study was to investigate the effects of the insertion depth of an immediately loaded implant on the stress distribution of the surrounding bone and the micromovement of the implant using the three-dimensional finite element analysis. MATERIALS AND METHODS: A total of five bone models were constructed such that the implant platform was positioned at the levels of 0.00 mm, 0.25 mm, 0.50 mm, 0.75 mm, and 1.00 mm depth from the crest of the cortical bone. A frictional coefficient of 0.3 and the insertion torque of 35 Ncm were simulated on the interface between the implant and surrounding bone. A static load of 178 N was applied to the provisional prosthesis with a vertical load in the axial direction and an oblique load at 30°with respect to the central axis of the implant, then a finite element analysis was performed. RESULTS: The implant insertion depth significantly affected the stress distribution on the surrounding bone. The largest micromovement value of the implant was 39.34 µm. The oblique load contributed significantly to the stress distribution and micromovement in comparison to the vertical load. CONCLUSION: Increasing the implant insertion depth was advantageous in dispersing the concentrated stress in the cortical bone and did not significantly affect the micromovement associated with early osseointegration failure.
Dental Implants ; Finite Element Analysis* ; Friction ; Immediate Dental Implant Loading ; Maxilla* ; Osseointegration ; Prostheses and Implants ; Torque

PURPOSE: Bone density at implant placement site is a key factor to obtain the primary stability of the fixture, which, in turn, is a prognostic factor for osseointegration and long-term success of an implant supported rehabilitation. Recently, an implant motor with a bone density measurement probe has been introduced. The aim of the present study was to test the objectiveness of the bone densities registered by the implant motor regardless of the operator performing them. MATERIALS AND METHODS: A total of 3704 bone density measurements, performed by means of the implant motor, were registered by 39 operators at different implant sites during routine activity. Bone density measurements were grouped according to their distribution across the jaws. Specifically, four different areas were distinguished: a pre-antral (between teeth from first right maxillary premolar to first left maxillary premolar) and a sub-antral (more distally) zone in the maxilla, and an interforaminal (between and including teeth from first left mandibular premolar to first right mandibular premolar) and a retroforaminal (more distally) zone in the lower one. A statistical comparison was performed to check the inter-operators variability of the collected data. RESULTS: The device produced consistent and operator-independent bone density values at each tooth position, showing a reliable bone-density measurement. CONCLUSION: The implant motor demonstrated to be a helpful tool to properly plan implant placement and loading irrespective of the operator using it.
Bicuspid ; Bone Density ; Immediate Dental Implant Loading ; Jaw ; Maxilla* ; Osseointegration ; Rehabilitation ; Tooth

PURPOSE: Patients who treated implant immediate loading within a week after implant placement at Wonkwang University Dental Hospital Implant Center were evaluated marginal bone resorption. These retrospective analyses are intended to reinforce the clinical evidence for the implant immediate loading. MATERIALS AND METHODS: Medical history and radiographic data were investigated, which were the patients' who treated implant immediate loading and restoration with provisional prostheses between January 2005 and June 2016, at Wonkwang University Dental Hospital Implant Center. Total number of implants was 70, marginal bone resorption was measured according to implant length, diameter and connection type. To measure marginal bone resorption, periapical radiographs were taken when the implants were placed and after 6 month. Statistical analysis was done in Mann-whitney U test and Kruskal-wallis test with SPSS 22.0 software (P < .05). RESULTS: Mean marginal bone resorption around immediately loaded implants according to implant connection type was shown 1.24 ± 0.72 mm in internal hexagon connection type and 1.73 ± 1.27 mm in external hexagon connection type. There was no statically significant difference in marginal bone resorption with implant length and diameter. CONCLUSION: Implants with immediated loading in internal hexagon connection type showed less marginal bone resorption significantly than in external hexagon connection type.
Bone Resorption* ; Humans ; Immediate Dental Implant Loading ; Prostheses and Implants ; Retrospective Studies*

Objective: To evaluate the pink and white esthetics of conventional and socket shield technique (SST) immediate implant restoration. Methods: Thirty volunteers were recruited according to preset criteria, and were assigned to 3 groups. Natural teeth group (ten undergraduates or postgraduates from Peking University School and Hospital of Stomatology in January 2020, n=10): all volunteers' maxillary anterior teeth were natural teeth with healthy gingiva, and none of the teeth were restored by crowns or composite. Conventional group and SST group (patients had a maxillary central incisor immediate implant placed in Department of Prosthodontics, Peking University School and Hospital of Stomatology during October 2016 to January 2021, n=10 for each group): the volunteer had an unrestored natural maxillary central incisor, and the contralateral maxillary central incisor was restored by conventional or SST immediate implant placement, temporization and all ceramic final restoration, photos were taken 12 months post-surgery. Three groups of evaluators namely layperson (staff from Second Clinical Division of Peking University School and Hospital of Stomatology and 2 family members, n=10), dental students (class 2015 undergraduates from Peking University School and Hospital of Stomatology, n=10) and prosthodontists (from Department of Prosthodontics, Peking University School and Hospital of Stomatology, n=10) were invited to assess the esthetics using pink esthetic score (PES) and white esthetic score (WES). The results were statistically analyzed. Results: PES and WES of natural teeth group [9(8, 10) and 8(7, 10)] were significantly higher than conventional group [7(6,8) and 7(6,9)] (H=287.08, 132.79,P<0.01) and SST group [7(6, 9) and 8(7, 9)] (H=216.01, 101.21, P<0.01). SST group yielded higher PES than the conventional group (H=-71.06, P<0.01), yet had similar WES (H=-31.57, P>0.05). Dental students had significant lower PES and WES than prosthodontists (H=-120.90, -218.86, P<0.01) and layperson (H=-109.55, 134.97, P<0.01). Prosthodontists and layperson got similar PES (H=-11.36, P>0.05), however yielded different WES (H=-83.89, P<0.01). Conclusions: SST immediate implant placement obtained better pink esthetics than conventional protocol 12-month after implant surgery, profession may have significant impact on evaluators during pink and white esthetic evaluation.
Crowns ; Dental Implants ; Dental Implants, Single-Tooth ; Esthetics, Dental ; Humans ; Immediate Dental Implant Loading ; Maxilla/surgery* ; Treatment Outcome