Implant Stability Measurements for Implants Placed at the Time of Extraction: A Cohort, Prospective Clinical Trial

Effect of antibacterial photodynamic therapy with chitosan nanoparticles on Aggregatibacter actinomycetemcomitans

BACKGROUND

This study aimed to assess the effect of antibacterial photodynamic therapy (aPDT) with chitosan nanoparticles on Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) in the culture medium.

MATERIALS AND METHODS

In this in vitro, experimental study, chitosan nanoparticles (CHNPs) containing indocyanine green (ICG) were first synthesized and characterized. A. actinomycetemcomitans was cultured on trypticase soy agar. The culture media containing A. actinomycetemcomitans were randomly subjected to the following six decontamination protocols: negative control subjected to sterile phosphate buffered saline (PBS) for 5 min, positive control exposed to 0.2 % chlorhexidine (CHX) for 5 min, exposure to 0.25 mg/mL ICG in the dark at 37 °C for 5 min, aPDT with 0.25 mg/mL ICG and diode laser (808 nm, 250 mW, 14.94 J/cm2, 30 s, 1 mm distance, 8 mm tip diameter), exposure to CHNPs containing 0.25 mg/mL ICG in the dark at 37 °C for 5 min, and aPDT with CHNPs containing 0.25 mg/mL ICG and diode laser. The number of colonies was counted, and analyzed by one-way ANOVA and Tamhane test (alpha=0.050).

RESULTS

Antimicrobial PDT with CHNPs, and CHX groups comparably showed the highest decontamination efficacy (P = 0.000).

CONCLUSION

The results showed optimal efficacy of aPDT with CHNPs containing 0.25 mg/mL ICG and 808 nm diode laser for reduction of A. actinomycetemcomitans colony count. Thus, aPDT appears to be as effective as CHX, but with fewer adverse effects.

Significance of bone morphology and quality on the primary stability of orthodontic mini-implants: in vitro comparison between human bone substitute and artificial bone

AIM

This study evaluated artificial bone models against a human bone substitute to assess the primary stability of orthodontic mini-implants (OMIs) at varying implant sites with different morphologies and qualities.

MATERIALS AND METHODS

A total of 1200 OMI placements of four types were inserted into four artificial bone models of different density (D1, D2, D3, D4) and into a human bone substitute (HB). The implants varied in diameter (2.0 and 2.3 mm) and length (9 and 11 mm). Each specimen had four implant sites: no defect, one-wall defect, three-wall defect, and circular defect. The implant stability quotient (ISQ) values were measured using resonance frequency analysis (RFA) and insertion placement torque values (IPT) were assessed for primary stability. Correlation analysis was performed to evaluate the different models.

RESULTS

The highest IPT value was registered for the 2.0 mm × 11 mm implant inserted into D1 with no defect (37.53 ± 3.02 Ncm). The lowest ISQ value was measured for the 2.3 mm × 9 mm OMI inserted into D3 with a circular defect (12.33 ± 5.88) and the highest for the 2.3 mm × 9 mm implant inserted into HB with no defect (63.23 ± 2.57). A strong correlation (r = 0.64) for IPT values and a very strong correlation (r = 0.8) for ISQ values was found between D2 and HB.

CONCLUSION

Bone defects and bone quality affected the primary stability of implants in terms of ISQ and IPT values. Results for bone model D2 correlated very well with the HB substitution material.

The impact of zero insertion torque on flapless immediate implant placement in the maxilla (5 years follow up clinical study)

Introduction: The achievement of good osseointegration in immediate implant placement can occur in the presence adequate primary stability. The insertion torque varies between cases depending on many factors. Aim: To assess clinically the impact of zero insertion torque on the survival of immediate implant placement in the maxilla for more than 5 years follow-up. Methods: A flapless immediate 2018 implants were in the maxilla in non-restorable single rooted teeth osteotomy site. The insertion torque of the implant was measured clinically by an integrated software. Results: The final insertion torque for 42 implants out of 2018 placed in fresh extraction sockets in the maxilla was zero (no primary stability). Their survival rate was 83.3%. Conclusions: The lack of certain conditions during immediate implant surgical installation and healing had the major effects on success. The loss of torque during immediate implant placement to zero may jeopardize the survival of the implants, but it may not be statistically significant with their failure and loss. The implant primary stability is not an absolute prerequisite to osseointegration; however, it may affect the implant survival rate.

Analysis of the sagittal root angle and its correlation with hard and soft tissue indices in anterior teeth for immediate implant evaluation: a retrospective study

BACKGROUND

To assess the root angle characteristics of maxillary incisors, and to analyze the relationship between the root angle and other implant-related anatomical indices to use the sagittal root angle as an index for immediate implant evaluation and design.

METHODS

A random sample consisting of 400 cone-beam computed tomography (CBCT) images and 65 maxillary plaster models were selected for the present study. CBCT and stereolithography (STL) scan images were imported as DICOM files into coDiagnostiX software for matching the hard and soft tissue. The angle between the long axis of the anterior tooth and the corresponding alveolar bone and implant-related hard and soft tissue indices were measured in the sagittal section. Descriptive statistics, frequency analysis, multi-level comparisons, and correlation analyses were performed.

RESULTS

The average sagittal root angles were 15° at the central incisor and 19° at the lateral incisor. The root angle in males was significantly larger than that in females, and increased with age. The largest angle, 22.35°, was found in the lateral incisors of the oldest (> 50 years old) male group. The root angle was found to correlate with coronal buccal bone thickness, coronal palatal bone thickness, apical buccal bone thickness, palatal bone thickness, and the below apex bone thickness.

CONCLUSIONS

The sagittal root angle could reflect the distribution of other implant-related anatomical indices, which may provide additional reference for the evaluation of immediate implant placement.

Effect of leukocyte and platelet rich fibrin (L-PRF) on stability of dental implants. A systematic review and meta-analysis

The aim of this study was to assess the impact, if any, of L-PRF application in an implant bed prior to implant placement, focusing on stability by means of implant stability quotient (ISQ) values. The literature was searched in a systematic way by means of the main databases and hand searching of the most relevant journals. The inclusion and exclusion criteria were used to determine the eligible studies included in this review. Only randomised controlled trials (RCT) and controlled clinical trials (CCT) were included. A total of four RCTs were included for data extraction. The risk of bias was deemed moderate to unclear. Meta-analysis was performed to assess the effect of L-PRF, on implant stability, immediately post-insertion in three studies, after one week from the implant placement in three studies and after four weeks for all the included studies. The fixed effects model has shown Hedges g statistic for the one week varying from 0.380 to 1.401 with a pooled figure of 0.764 (95% CI 0.443 to 1.085) and for four weeks varying between 0.74 and 1.1 with a combined effect of 0.888 (95% CI 0.598 to 1.177). The results for both intervals were in favour of the use of L-PRF while the statistical difference immediately post-insertion was not statistically significant. The present systematic review, though acknowledging its limitations, suggests that L-PRF has a positive effect on secondary implant stability and that needs to be correlated to the clinical practice to measure the actual clinical effect by means of reducing treatment times.

Effect of Different Implant Designs on Strain and Stress Distribution under Non-Axial Loading: A Three-Dimensional Finite Element Analysis

Implant design evolved alongside the development of implant therapy. The purpose of this finite element analysis (FEA) study was to analyze the influence of different implant designs on the stress and strain distribution to the implants and surrounding bone. Three implant designs with the same length and diameter were used. The three-dimensional geometry of the bone was simulated with a cortical bone of three different thicknesses and two medullar bone densities: low density (150 Hounsfield units) and high density (850 Hounsfield units). A 30° oblique load of 150 N was applied to the implant restoration. Displacement and stress (von Mises) results were obtained for bone and dental implants. The strain and stress distributions to the bone were higher for the tissue-level implant for all types of bone. The maximum principal strain and stress decreased with an increase in cortical bone thickness for both cancellous bone densities. The distribution of the load was concentrated at the coronal portion of the bone and implants. All implants showed a good distribution of forces for non-axial loads, with higher forces concentrated at the crestal region of the bone–implant interface. Decrease in medullar bone density negatively affects the strain and stress produced by the implants.

Implant Treatment for a Patient With Large Condensing Osteitis: Case Report

Chronic endodontic infections are associated with osseous changes in the peri-apical regions. Dental implants are often placed after the extraction of hopeless teeth with periapical infections. This clinical report describes a patient with a radiopaque mass attached to the root apex of the mandibular right second premolar tooth (No. 45). The differential diagnoses of the radiopaque mass were bone- and tissue-borne diseases. Based on the clinical and radiologic findings (bone density and trabeculation of the bone), the definitive diagnosis of the osseous mass was condensing osteitis. The osseous tumor associated with tooth 45 was atraumatically extracted under local anesthesia. Guided bone regeneration was performed immediately after extraction of tooth 45, and a dental implant was placed in the site after 6 months of healing.

Facial Gingival Changes With and Without Socket Gap Grafting Following Single Maxillary Anterior Immediate Tooth Replacement: One-Year Results

This 1-year prospective study evaluated horizontal and vertical facial gingival tissue changes after immediate implant placement and provisionalization (IIPP) with and without bone graft in the implant-socket gap (ISG). During IIPP, 10 patients received bone graft material in the ISG (G group), while the other 10 patients did not (NG group). The implants were evaluated for implant stability quotient (ISQ), modified plaque index (mPI), modified bleeding index (mBI), marginal bone level (MBL), facial gingival level (FGL), and facial gingival profile (FGP) changes. The mean ISQ value at 9-month follow-up was statistically significantly greater than on the day of implant surgery (P < .05). The mPI and mBI scores demonstrated that patients were able to maintain a good level of hygiene. There were no statistically significant differences in the mean MBL changes between the G and NG groups (P > .05). There were statistically significant differences in FGL changes between the G (-0.77 mm) and NG (-1.35 mm) groups (P = .035). There were no statistically significant differences in FGP changes between the G and NG groups (P > .05). However, statistically significant differences were noted in FGP change between the 3–12 and 0–12 month intervals in both groups (P < .05). Within the limitations of this study, although no significant differences were noted in FGP changes between groups, G group experienced significantly less FGL changes than NG group. Bone graft material placement into ISG seems to be advantageous for tissue preservation during IIPP. However, future long-term studies, with larger sample size, are needed to validate the efficacy of such procedure

Initial Stability Measurements of Implants Using a New Magnetic Resonance Frequency Analyzer With Titanium Transducers: An Ex Vivo Study

The establishment of dental implant stability is mandatory for successful osseointegration. Resonance frequency analysis (RFA) is the most frequently used method for the clinical measurement of implant stability. The purpose of the present study was to evaluate the reliability of the recently developed RF analyzer Penguin RFA and to compare it with the traditional RF analyzer Osstell ISQ. Sixty implants were inserted into fresh steer vertebrae and pelvis. Implant stability was measured using Penguin RFA by its transducers (multipegs) and Osstell ISQ by its transducers (smartpegs). Additionally, stability was measured by multipegs with Osstell ISQ and by smartpegs with Penguin RFA. The intraobserver and interobserver reliability of Penguin RFA were estimated by the intraclass coefficient (ICC). Mean implant stability quotients (ISQs) measured with Osstell ISQ were higher than the ISQs measured with Penguin RFA (P < .05). The intra- and interobserver reliability of Penguin RFA were considered as excellent (ICC > 0.7). For Osstell ISQ, no significance in ISQs was detected between the readings by smartpegs and multipegs (P > .05), while for Penguin RFA ISQs by smartpegs were significantly higher than the ISQs by multipegs (P <.05). The recently developed Penguin RFA is reliable and can be used in clinical practice for the measurement of dental implant stability regardless of the bone type. The multipegs originally manufactured for the Penguin RFA is also compatible with Osstell ISQ.

[The use of autogenous free vascularized fibula transplant for the correction of severe mandibular atrophy]

The purpose of the study was to increase the effectiveness of surgical treatment and rehabilitation of patients with severe mandibular atrophy by means of autogenous free vascularized fibula transplant use with subsequent dental implants placement in the reconstructed mandible and implant-retained fixed dentures. In 2017 5 female patients underwent surgical treatment of severe mandibular atrophy with autogenous free vascularized fibula transplant in Maxillofacial Surgery department of CRID with additional nonvascularized iliac bone grafts and functional rehabilitation with implant-supported constructions in two of the cases. Due to its form, length and vascularization fibular bone represents a good plastic material for full length mandibular alveolar part reconstruction. The inclusion of the skin paddle in the autogenous free vascularized fibula transplant promotes secure primary closure of the surgical wound in the oral cavity. The use autogenous free vascularized fibula transplant in patients with severe mandibular atrophy with demands a thorough presurgical planning and intraoperative modeling.

Influence of a Novel Surface of Bioactive Implants on Osseointegration: A Comparative and Histomorfometric Correlation and Implant Stability Study in Minipigs

Purpose: The objective of this study was to assess the influence of a novel surface of dental implants (ContacTi^®) on the osseointegration process in a minipig model. The surface was compared with other existing surfaces on the market (SLA^® and SLActive^®) by employing bone implant contact analysis (BIC) and implant stability. Method: Twelve minipigs were used with prior authorisation from an ethics committee. Three types of surfaces were tested: SLA^® (sand-blasted acid-etched titanium), SLActive^® (same but hydrophilic, performed under a nitrogen atmosphere), and ContacTi^® (alumina particle bombardment of titanium, bioactivated when treated thermochemically) in 4.1 mm × 8 mm implants with internal connection and a polished neck. Twelve implants of each surface type (N = 36) were placed, sacrificing 1/3 of the animals at 2 weeks of placement, 1/3 at 4 weeks and the remaining 1/3 at 8 weeks. Numerical variables were compared with Analysis of Variance, and the correlation between ISQ and BIC was established with the Spearman’s rank correlation coefficient. Results: SLActive^® and ContacTi^® surfaces showed elevated osteoconductivity at 4 weeks, maintaining a similar evolution at 8 weeks (large amount of mature lamellar tissue with high maturity and bone quality). The SLA^® surface showed slower maturation. The ISQ values in surgery were elevated (above 65), higher at necropsy and higher at 4 and 8 weeks in the SLA^® group than in the other two (SLActive^® and ContacTi^®). No significant correlation was found between ISQ and BIC for each implant surface and necropsy time. Conclusion: The three surfaces analysed showed high RFA and BIC values, which were more favourable for the SLActive^® and ContacTi^® surfaces. No statistical correlation was found between the RFA and BIC values in any of the three surfaces analysed.

Low-level laser therapy affects osseointegration in titanium implants: resonance frequency, removal torque, and histomorphometric analysis in rabbits

Objectives

The purpose of this study was to investigate the effects of low-level laser therapy (LLLT) with a diode gallium-aluminum-arsenide (Ga-Al-As) low-level laser device on the healing and attachment of titanium implants in bone.

Materials and Methods

Thirteen New Zealand white male rabbits weighing 3.0±0.5 kg were used for this study. Dental titanium implants (3.75 mm in diameter and 8.5 mm in length, US II RBM plus fixture; Osstem, Seoul, Korea) were implanted into both femurs of each rabbit. The rabbits were randomly divided into a LLLT group and a control group. The LLLT was initiated immediately after surgery and then repeated daily for 7 consecutive days in the LLLT group. Six weeks and 12 weeks after implantation, we evaluated and compared the osseointegration of the LLLT group and control group, using histomorphometric analysis, removal torque testing, and resonance frequency analysis (RFA). The results were statistically significant when the level of probability was 0.05 or less based on a non-parametric Mann-Whitney U-test.

Results

The implant survival rate was about 96%. Histologically and histomorphometrically, we observed that the titanium implants were more strongly attached in LLLT group than in control group. However, there was no significant difference between the LLLT group and control group in removal torque or RFA.

Conclusion

Histologically, LLLT might promote cell-level osseointegration of titanium implants, but there was no statistically significant effects.

Immediate 3-dimensional ridge augmentation after extraction of periodontally hopeless tooth using chinblock graft

Background

The aim of the present study was to evaluate clinically and radiographically, the efficacy of immediate ridge augmentation to reconstruct the vertical and horizontal dimensions at extraction sites of periodontally hopeless tooth using an autogenous chin block graft.

Material and Methods

A total of 11 patients (7 male & 4 female) with localized advanced bone loss around single rooted teeth having hopeless prognosis and indicated for extraction were selected for the study. The teeth were atraumatically extracted and deficient sites were augmented using autogenous chin block graft. Parameters like clinically soft tissue height - width and also radiographic ridge height -width were measured before and 6 months after augmentation. Obtained results were tabulated and analysed statistically.

Results

After 6 months of immediate ridge augmentation, the mean gain in radiographic vertical height and horizontal width was 7.64 + 1.47 mm (P = 0.005) and 5.28 + 0.46 mm (P = 0.007) respectively which was found to be statistically significant (P < 0.05). Mean change of width gain of 0.40mm and height loss of 0.40mm of soft tissue parameters, from the baseline till completion of the study at 6 months was observed.

Conclusions

The present study showed predictable immediate ridge augmentation with autogenous chin block graft at periodontally compromised extraction site. It can provide adequate hard and soft tissue foundation for perfect 3-Dimensional prosthetic positioning of implant in severely deficient ridges.

Key words:Immediate ridge augmentation, periondontally hopeless tooth, autogenous chin graft, dental implant.

Evaluation of extrashort 4-mm implants in mandibular edentulous patients with reduced bone height in comparison with standard implants: a 12-month results

OBJECTIVE

The aim of this research was to evaluate the primary stability, the marginal bone loss, the survival, and the success criteria, of 4-mm-length implants compared with implants of conventional length supporting fixed prostheses.

MATERIALS AND METHODS

Ten patients were selected for treatment of their atrophic edentulous jaws. Each patient received the following treatment: six dental implants were inserted, two anterior implants of conventional length (10-mm) in the interforaminal area and four posterior short implants of 4-mm length (Standard Plus, Roxolid, SLActive, Institut Straumann AG). The implants supported screw-retained fixed complete dentures. Examinations were conducted at day 0, three, six, and twelve months after surgery for the evaluation of the implant primary stability, secondary stability, crestal bone loss and survival by clinical evaluations, insertion torque values, resonance frequency analysis (RFA), and periapical radiography, respectively.

RESULTS

Sixty implants were inserted in ten patients. Mean insertion torque was slightly lower for 4-mm implants than 10-mm implants (38.1 Ncm vs. 42.2 Ncm) but without statistically significant difference. Implant stability was similar for extrashort and conventional implants. Marginal bone loss was similar for both groups for all the time periods. One short implant was lost before loading. The survival rates twelve months after implant placement were of 97.5% and 100% for short and conventional implants, respectively. Similarly, implant stability as measured by RFA was nonsignificantly lower for the 4-mm implants compared to the 10-mm implants. The marginal bone loss was lower for short implants three, six, and twelve months after the surgery without statistical significant difference.

CONCLUSIONS

Within the limitations of this study, we conclude that short dental implants (8 mm or less in length) supporting single crowns or fixed bridges are a feasible treatment option with radiographic and clinical success rates similar to longer implants for patients with compromised ridges. Long-term data with larger number of implants and subjects are needed to confirm these preliminary results.

Effect of location on primary stability and healing of dental implants

PURPOSE

To study implant primary stability and bone healing using resonance frequency analysis in different anatomical locations 4 months after placement.

MATERIAL AND METHODS

Fifty-six partially edentulous patients restored by dental implants were included. Overall, 214 implants were placed without bone or soft tissue augmentation. All implants were placed with the same drilling protocol and implant insertion torque (35-40 N · cm).

RESULTS

The mean implant stability quotient (ISQ) value at baseline for all the locations was 75.4 mm (95% confidence interval, 74.20-76.59 mm). Higher ISQ values were found in the mandible. A significant difference between ISQ values of each location (P < 0.001) was identified. The mean values obtained showed an increase (3.4%) in all the locations, being greater in the posterior lower and upper maxillae (3.8%), whereas for the anterior maxilla, it was the least (1.5%) 4 months after healing. This increase was statistically significant in the posterior upper and lower maxillae (P < 0.001).

CONCLUSION

Higher implant stability was found in mandible compared with maxilla in both periods, immediately after insertion and 4 months later. Therefore, according to ISQ values, restoring implants immediately after insertion or after a healing period of 4 months represents safe time points.

Survival of Implants in Immediate Extraction Sockets of Anterior Teeth: Early Clinical Results

BACKGROUND

The aims and objectives of this study were placement of implants in freshly extracted sockets of anterior teeth and to evaluate the implant stability, peri-implant radiolucency and gingival inflammation around implant over a short period of 30 months.

MATERIALS AND METHODS

A total of 12 patients (8 male and 4 female), ranging in the age from 20 to 50 years, from March 2007 to June 2007, were evaluated for immediate implant placement into 22 fresh extraction sockets. Only maxillary and mandibular anterior teeth/roots (central incisors, lateral incisors and canines) were considered for replacement with implants. One piece implant with integrated abutment and integrated surface, non-submerged, threaded and tapered at apical 5 mm, sand-blasted and acid etched surfaced implants (HI-TEC TRX-OP Implants of Life Care Company) were used.

RESULTS

The mobility was not present in any of the implants at all the follow up visits. There were 2 implants at 6 month, 1 implant at 12 month, 1 implant at 18 month visits, showing peri-implant radiolucency at some sites at bone to implant contact site. Severe gingival inflammation was not observed in any of the implant site. At every follow-up visit, every implant met the criteria of success and none was found to be failed over a 30 months duration i.e. 100% success rate was achieved by implants in immediate extraction socket.

CONCLUSION

The success rate of implant survival in this study was found 100%. These implants have fulfilled all the criteria of implant success and based on the defined criteria, the success rate of implants placed in immediate extraction sockets of anterior teeth compared favorably with the conventional implants. The early results of the present study showed that high survival rates with the implants in immediate extraction sockets can be achieved.

Stability of implants placed in fresh sockets versus healed alveolar sites: Early findings

OBJECTIVES

The present study measured implant stability quotient (ISQ) values at three different time points after surgical procedures to compare whether the stability values differed between implants placed in fresh extraction sockets versus healed alveolar sites.

MATERIALS AND METHODS

To measure implant stability, resonance frequency analysis (RFA) was performed in 77 patients (53 women, 24 men) with a total of 120 dental implants. These implants were divided into two groups: Group 1 included 60 implants in healed alveolar sites (22 in the maxilla, 38 in the mandible), and Group 2 included 60 implants in fresh sockets (41 in the maxilla, 19 in the mandible). Implant stability was measured immediately at implant placement (baseline), 90, and 150 days later. Statistical analysis was made using a multivariate regression linear model at implant level (α = 0.05).

RESULTS

Overall, the means and standard deviations of the ISQ values were 62.7 ± 7.14 (95% confidence interval [CI], 39-88) at baseline, 70.0 ± 6.22 (95% CI, 46-88) at 90 days, and 73.4 ± 5.84 (95% CI, 58-88) at 150 days. In Group 1, the ISQs ranged between 64.3 ± 6.20 and 75.0 ± 5.69, while in Group 2, presented lower values that ranged between 61.2 ± 8.09 and 71.9 ± 5.99 (P = 0.002). Anatomic location and times periods were the only identified variables with an influence on ISQ values at implant level (P < 0.0001).

CONCLUSIONS

The stabilities of the implants placed in the fresh sockets and in healed sites exhibited similar evolutions in ISQ values and thus osseointegration; however, the implants in the healed alveolar sites exhibited superior values at all time points.

Impact of Bone Quality and Implant Type on the Primary Stability: An Experimental Study Using Bovine Bone

The purpose of this in vitro study was to compare the primary stability and removal torque of bone level and tissue level implants in different bone qualities. Twenty tissue level and bone level implants (3.3 × 10 mm and 4.1 × 10 mm) were used for assessing the stability in type II and type IV bone. Forty bovine rib blocks were used in this study. The primary stability of the implant was measured by the resonance frequency using an Osstel device. The removal torque values (RTV) of the implants was assessed using a digital torque gauge instrument. The implant stability quotient (ISQ) values and the RTV showed a marginally higher stability with bone level implants as compared to tissue level implants. However, these differences were not statistically significant in both type of bone used (P &gt; 0.05). On the other hand, compared to type IV, type II bone showed significant differences in the ISQ (P &lt; 0.01) and RTV (P &lt; 0.001) of bone level and tissue level implants. The study concluded that bone quality is an important factor in establishing primary stability than the implant dimension. Bone level and tissue level implants of same dimensions can be selected based on the esthetic demands since they showed similar mechanical properties.

Immediate placement of single implant simultaneously with immediate loading in a fresh socket associated to periapical infection: A clinical case report

Early restoration of the masticatory function, phonatory and aesthetics is some of the current goals of the therapy based on endosseous implants. Facing the classic protocols of implant insertion, which recommend a period of several months between extraction and implant placement, alternatives have been developed that demonstrate that immediate implant placement after tooth extraction permits adequate osseointegration, even in those cases where there is a periapical disease. The immediate restoration of implants after placement is a possibility where aesthetic requirements are high. This article presents a case with immediate implant placement and immediate loading of a first upper premolar with prior periapical pathology due to a vertical fracture. The immediate prosthetic was performed using the extracted crown, which is adapted to be attached to a titanium temporary abutment using a resin cement. After a 4 month healing period work began on the final prosthetic crown. The screw crown was made of zirconium oxide with a covering feldspathic ceramic. At the 12-month follow-up, there were no mechanical or biological complications. The patient gave high satisfaction marks for the overall treatment, giving visual analogue scale score of nine. Immediate post-extraction implants have arisen as an alternative to traditional implants on completely healed bone. Their main aim is to reduce treatment time and number of surgical procedures, along with other objectives such as reduced bone re-absorption and improved aesthetics.

Key words:Post-extraction implants, immediate loading prosthetic, implant-retained prosthesis, periapical disease, vertical fracture.

Resonance frequency analysis, insertion torque, and bone to implant contact of 4 implant surfaces: comparison and correlation study in sheep

INTRODUCTION

Primary stability is evaluated using resonance frequency analysis (RFA) and insertion torque (IT). Although there is a strong correlation between RFA and IT, studies failed to find a correlation between RFA and bone to implant contact (BIC) or IT and BIC.

OBJECTIVE

To compare RFA, IT, and BIC of SLA, SLActive, Euroteknika, and TiUnite implant surfaces and evaluate the correlation between them.

MATERIALS AND METHODS

Thirty-two implants were placed in 8 sheep. RFA and IT were recorded. Animals were killed at 1 and 2 months.

RESULTS

A significant difference was found in RFA between the 4 surfaces. No significant difference was found for IT. Mean BIC was different between all 4 surfaces. A significant positive correlation was found between RFA and IT with SLA. No significant correlation was found between RFA and BIC and between IT and BIC at 1 and 2 months.

CONCLUSIONS

Implants with 4 different surfaces have similar IT values but different RFA and BIC. Additionally irrespective of the implant surface, there is no correlation between IT and BIC and between RFA and BIC.

Clinical study on survival rate of short implants placed in the posterior mandibular region: resonance frequency analysis

OBJECTIVE

Short implants are increasingly used, but there is doubt about their performance being similar to that of regular implants. The aim of this study was to compare the mechanical stability of short implants vs. regular implants placed in the edentulous posterior mandible.

MATERIAL AND METHODS

Twenty-three patients received a total of 48 short implants (5 × 5.5 mm and 5 × 7 mm) and 42 regular implants (4 × 10 mm and 4 × 11.5 mm) in the posterior mandible. Patients who received short implants had <10 mm of bone height measured from the bone crest to the outer wall of the mandibular canal. Resonance frequency analysis (RFA) was performed at time intervals T0 (immediately after implant placement), T1 (after 15 days), T2 (after 30 days), T3 (after 60 days), and T4 (after 90 days).

RESULTS

The survival rate after 90 days was 87.5% for the short implants and 100% for regular implants (P < 0.05). There was no significant difference between the implants in time intervals T1, T2, T3, and T4. In T0, the RFA values of 5 × 5.5 implants were higher than values of 5 × 7 and 4 × 11.5 implants (P < 0.05). A total of six short implants that were placed in four patients were lost (three of 5 × 5.5 mm and three of 5 × 7 mm). Three lost implants started with high ISQ values, which progressively decreased. The other three lost implants started with a slightly lower ISQ value, which rose and then began to fall.

CONCLUSIONS

Survival rate of short implants after 90 days was lower than that of regular implants. However, short implants may be considered a reasonable alternative for rehabilitation of severely resorbed mandibles with reduced height, to avoid performing bone reconstruction before implant placement. Patients need to be aware of the reduced survival rate compared with regular implants before implant placement to avoid disappointments.

The Evaluation of the Reliability of Periotest for Implant Stability Measurements: An In Vitro Study

Periotest (Medizintechnik Gulden, Modautal, Germany) is a widely accepted implant stability measurement method, although the reliability is not well known. The aim of this in vitro study was to investigate the reliability of the Periotest in implant stability measurements. Thirty implants were placed in 3 cow ribs. The stability of each implant was measured by insertion torque, resonance frequency analyses, and Periotest and then compared. The Periotest values (PTVs) were measured by 4 different examiners. The measurements were repeated twice in both the buccal and mesial directions, for each implant at 2-hour intervals and the intra- and interobserver reliability of Periotest was measured. Results showed that the intraobserver reliability of the Periotest was excellent for the buccal PTVs but fair to poor for the mesial PTVs. The interobserver reliability of the Periotest was excellent for the buccal PTVs but poor for the mesial PTVs. No significance was found between the PTVs and IT values (P = .803) and PTVs and ISQ values, whereas a 47.1% significant correlation was detected between the IT values and ISQ values (P = .009). The present study indicates that only Periotest measurements from buccal result in excellent intra- and interobserver reliability for the quantification of the implant stability.

A Four-Year Survival Rate Multicenter Prospective Clinical Study on 377 Implants: Correlations Between Implant Insertion Torque, Diameter, and Bone Quality

The purpose of this study was to evaluate the survival rate and incidence of prosthetic complications in 377 implants with a double octagon connection. Furthermore, the correlations among implant dimensions (diameter and length), bone quality, and insertion torque were investigated. A 4-year multicenter prospective clinical study was designed to evaluate the survival rate of 377 dental implants inserted in 189 patients between January 2004 and April 2010. After an average follow-up of 46 months, the implant survival rate was 99.7%, and the incidence of complication was 0.53%. Moreover, insertion torque was statistically related in a significant way to implant diameter. The connection system seemed to reduce the risk that the prosthetic component screw would loosen. Within the limits of this study, it was observed that a wider diameter corresponded to a higher implant primary stability. Implant length did not seem to be critical in obtaining higher primary stability.

In vitro evaluation of resonance frequency analysis values to different implant contact ratio and stiffness of surrounding material

PURPOSE

The present study was aimed to evaluate the influence of implant contact ratio and stiffness of implant-surrounding materials on the resonance frequency analysis (RFA) values.

MATERIALS AND METHODS

Seventy resin blocks that had the different amounts (100, 50, 30, 15%) of resin-implant contact (RIC) were fabricated. Ten silicone putty blocks with 100% silicone-implant contact were also made. The implants with Ø5.0 mm × 13.0 mm were placed on eighty specimen blocks. The RFA value was measured on the transducer that was connected to each implant by Osstell Mentor. Kruskal-Wallis and Scheffe's tests (α=.05) were done for statistical analysis.

RESULTS

The control resin group with 100% RIC had the highest RFA value of 83.9, which was significantly different only from the resin group with 15% RIC among the resin groups. The silicone putty group with 100% contact had the lowest RFA value of 36.6 and showed statistically significant differences from the resin groups.

CONCLUSION

Within the limitations of this in vitro study, there was no significant difference in the RFA values among the resin groups with different RIC's except when the RIC difference was more than 85%. A significant increase in the RFA value was observed related to the increase in stiffness of material around implant.

Preserving soft tissue after placing implants in fresh extraction sockets in the maxillary esthetic zone and a prosthetic template for interim crown fabrication: a prospective study

STATEMENT OF PROBLEM

The technique of immediate implant placement is said to have success rates similar to those of implantation into a healed socket. An implant-supported restoration in an esthetic area must achieve a harmonious balance of functional, esthetic, and biologic imperatives to be considered effective.

PURPOSE

The purpose of this clinical study was to assess the height of the interproximal gingival papillae adjacent to immediate implants with immediate loading. The hypothesis was that specific positioning of the proximal contact areas of the interim crowns would facilitate the maintenance or regeneration of the interproximal papilla.

MATERIAL AND METHODS

Twenty-eight participants were provided implants (n=36) in the anterior maxillary area that were loaded with a specifically contoured interim crown immediately after tooth extraction. The proximal contact areas of the interim crowns were positioned 5 to 6 mm incisal to the interproximal bony crest by using a prosthetic template. Papilla height was classified according to a previously described papilla index. A comparison was made between the papilla height before the extraction, at interim crown placement after the implant placement, and at 6 and 12 months postoperatively. Parametric and nonparametric tests were used when appropriate (Kolmogorov-Smirnov). Significance was expressed at the α=.05 level. Cross tables were used to describe the changes in the papilla index score.

RESULTS

During the 1-year follow-up, the score of the distal and mesial papilla indices increased significantly (repeated-measures Friedman exact test; P=.035 and P=.002).

CONCLUSIONS

This prospective study indicated that the use of a prosthetic template for positioning an interim crown on immediately placed implants and for ensuring that the proximal contact areas of the crown with adjacent teeth are 5 to 6 mm incisal to the interproximal bony crest does not seem to hinder the maintenance or regeneration of the height of the interproximal papillae.

The comparison between implant stability quotient and bone-implant contact revisited: an experiment in Beagle dog

BACKGROUND

Resonance frequency analysis (RFA) is applied clinically for the assessment of implant stability, and the relevance of this application is widely accepted. However, the relationship between resonance frequency (RF) and other parameters of implant stability, such as the histomorphometrical bone-to-implant contact (BIC) parameter, has become controversial in the last decade.

OBJECTIVE

To analyse and clarify the controversial relationship between RF and histomorphometrical BIC measurements.

MATERIAL AND METHODS

A total of 36 dental implants (9 mm length, Ø 4.0 mm; Biohorizons(®) Implant Systems Inc., Birmingham, AL, USA) with a soluble blasting media (sandblasting with soluble particles) surface were implanted in six beagle dog mandibles. RFA assessments were performed with a magnetic Osstel Mentor(®) device at the time of implant installation, and during the monitoring period at weeks 1, 2, 4, 6 and 8, before implant retrieval. The dogs were sacrificed and the implants were removed in block after 8, 6, 4, 2, 1 and 0 weeks, respectively. One group was obtained at time 0, immediately after the implantation. The samples were embedded in methyl methacrylate polymers (Technovit(®) ) and cut along their long axis. BIC values were assessed by a non-subjective and systematic method based on backscattered scanning electron microscopy (BS-SEM) images. BIC% at the different time points was compared with the corresponding implant stability quotient (ISQ) values of the RFA assessment.

RESULTS

No statistically significant correlation between BIC and ISQ values (Osstell Mentor(®) ) was identified. The absence of a relationship between these two parameters is in agreement with several previous studies in humans and experimental animals.

CONCLUSIONS

The lack of correlation between BIC and ISQ values suggests that ISQ as determined by RFA is not able to identify the relationship between RF and histomorphometrical data.

Increased crown-to-implant ratio may not be a risk factor for dental implant failure under appropriate plaque control

OBJECTIVE

The aim of this study was to evaluate whether increased crown-to-implant (C/I) ratio influences implant stability or not under proper healthy control of peri-implant mucosa. The hypothesis of this study is that implant stability can be maintained despite High C/I, under appropriate plaque control.

MATERIALS AND METHODS

Five male Beagle-Labrador hybrid dogs (2 years old) were used. Their bilateral mandibular premolar extraction was performed. After allowing 12 weeks for bone healing, 3 types of vertical marginal bone loss were simultaneously prepared randomly. Then, 30 titanium implants were placed in the edentulous areas and defined as High C/I, Mid C/I and Low C/I groups. This time point was designated as the baseline (0 Week). Twelve weeks after implant placement, metal superstructures were cemented to the implants and an occlusal plate was set at the opposite side. At the same time, Calcein green was injected for remodeling evaluation. Implants were loaded by feeding the dogs a hard pellet diet. Tooth brushing was performed 5 days per week during the study to maintain healthy peri-implant mucosa. Twenty-four weeks following implant placement, the interface structure was evaluated clinically, radiologically, and histologically.

RESULT

Implant stability quotient (ISQ) increased with time in all 3 groups, without any significant correlation with the C/I value (p >0.05). Moreover, mean marginal bone loss adjacent around implants in all 3 groups ranged between 0.11 and 0.19 mm, with no significant difference (p >0.05). Many fluorescence-labeled bones are shown in the High C/I group. It is considered that high remodeling activity prevent marginal bone loss in the High C/I group and this may provide favorable implant stability under proper plaque control.

CONCLUSION

These findings suggest that increased C/I may not be a risk factor for implant failure if the peri-implant mucosa is kept healthy, as was the case in this animal model.

Evaluation of implants placed immediately or delayed into extraction sites

AIMS AND OBJECTIVES

To compare the success rate of implant placed immediately in extraction socket vs implant placed delayed in extraction socket.

MATERIALS AND METHODS

The study comprised of 8 patients (6 male and 2 female, aged from 14 to 58 year) for evaluation of implant placement immediately (i.e. Group - A) or delayed (i.e. Group - B) into extraction site, in which at 12 sites implants were placed.

RESULTS

The inclusion criteria for implantation was tooth/teeth with one or two degree mobility, root stumps, tooth with failure root canal treatment and extraction sockets. HI-TEC TRX-OP (Life Care) with abutment, non-submerged, tapered at apical 5 mm, sand-blasted & acid etched surfaced implants were used. These are one stage single implants made of commercially pure titanium. The length of implants used was 10 mm and 13 mm and diameter was 3.70 mm and 4.50 mm. The vertical bone dimension was determined by palpation and radiograph (intra-oral periapical, orthopantomograph and dentascan in some patients). Gingival condition, bone condition was examined clinically and radiographically.

DISCUSSION

Post-operative evaluation was done under clinical parameters (i.e. Pain (VAS), Swelling, Stability (By Glickman method), Gingival status, Probing depth (By Williams Periodontal probe), Patient's compliance / satisfaction, Complications (If any) and Radiological parameters was (Intra-oral periapical radiograph, orthopantomograph, Dentascan).

CONCLUSION

Overall conclusion drawn from this study was that both the groups are showing similar results but Group-A is slightly better than Group-B.

Timing of implant placement and augmentation with bone replacement material: clinical assessment at 8 and 16 months

PURPOSE

The purpose of this study is to evaluate implants placed at different times of bone augmentation.

MATERIALS AND METHODS

Four implants were placed in seven dogs: one at a 6-month bovine mineral grafted site (6-month Bio-Oss® grafted site [6mBio]), one at a grafted membrane-protected simultaneously augmented (Fresh Bio-Oss® grafted site [FrBio]) site, one at a clotted (nongrafted clotted membrane-protected site [Clot]) membrane-protected site, and one at a pristine (nongrafted uncovered site [Cont]) site. Implants were exposed after 6 months. The same protocol was repeated on the contralateral side, at a delay of 8 months. Peri-implant care was performed throughout the hygienic phase (2 and 10 months, respectively) every 48 to 72 hours. Probing depth and bleeding on probing were recorded. Implant stability was determined by a Periotest® (Medizintechnik Gulden, Modautal, Germany). Statistical analysis was conducted using analysis of variance with repeated measures.

RESULTS

Average probing depth at the simultaneously grafted sites was 2.21 mm and 2.03 mm at 8 and 16 months, respectively. At the 6-month grafted sites, it was 1.96 mm and 1.57 mm. At the Clot sites, it was 2.68 mm and 2.07 mm, and 2.21 mm and 1.82 mm at the Cont sites, respectively. The average bleeding on probing was 0.50 and 0.42 at the FrBio sites, and 0.35 and 0.07 at the 6mBio sites during the respective periods. At the Clot sites, it was 0.50 and 0.28, and at the Cont sites, 0.43 and 0.21, respectively. Probing depth significantly reduced over the time at 6mBio, Clot, and Cont sites (p < .03). Average implant stability score at the FrBio sites was -0.24 and -0.27, and -0.50 and -0.46 at the 6mBio sites, at 8 and 16 months, respectively. At the Clot sites, it was -0.35 and -0.46. Cont sites averaged -0.37 at both periods. Implant stability was significantly higher (p < .005) comparing 6mBio over FrBio, 6mBio over Cont, and Clot over FrBio sites.

CONCLUSIONS

Immediate and delayed augmentations are safe modes. Probing depth and bleeding indices gradually improved along time. Implant stability was higher at the delayed mode.

Influence of surgical technique, implant shape and diameter on the primary stability in cancellous bone

Achievement of primary stability during surgical placement of dental implants is one of the most important factors for successful osseointegration depending on various anatomical, surgical and implant-related factors. Resonance frequency analysis (RFA) has been shown as a non-invasive and objective technique for measuring the stability of implants. The aim of this study was to evaluate the effect of some surgical and implant-related factors in enhancing primary stability and to estimate a correlation between RFA and insertion torque (IT) in proximal regions of cow ribs representing cancellous bone. Fifteen implant beds were prepared in the most proximal region of six fresh cow ribs. Ninety implants with three different shapes and two different diameters were placed with two different surgical techniques, and the primary stability was compared using RFA and IT. Significantly higher RFA and IT values were achieved when under-dimensioned drilling was used as the surgical method (P<0·01); significantly higher IT values were obtained with the use of wider implants (P<0·01) and partially conical Astra Tech implants showed the highest IT values (P<0·01). When all the implants were considered, significant correlations between the IT and RFA values were noted (%40·6, P<0·05). Partially conical implants with a wide diameter to be placed with the modified surgical technique proposed appear to be useful in enhancing the primary stability in cancellous bone.

Implant insertional torque values predict outcomes

PURPOSE

To study the relationships between insertional torque values (ITVs) recorded during implant placement and implant healing times and cumulative survival rates.

MATERIALS AND METHODS

This retrospective study evaluated 174 Osseotite 6.0-mm-diameter, straight-wall, threaded dental implants (BIOMET 3i, Palm Beach Gardens, FL) placed in 172 consecutive patients by the primary author. All implants were placed immediately into mandibular first or second molar extraction sockets after extraction. ITVs were recorded at placement. Implants were evaluated 3 months after surgery before discharge to restorative dentists for restoration. The post-restorative follow-up ranged from 2 years 1 month to 4 years 8 months (median and mean of 3 years 1 month [SD, 4.95]).

RESULTS

Of the implants, 3% (n = 5) were removed at the time of surgical placement because of perceived clinical mobility of the implants within the osteotomies. The implants that were stable at the time of implant placement (n = 169) were placed into 1 of 3 groups relative to the specific ITVs at implant placement: group 1, low ITV, 29% (n = 49); group 2, medium ITV, 23% (n = 39); and group 3, high ITV, 48% (n = 81). Cumulative survival rates for each group were 86% for low ITV, 90% for medium ITV, and 96% for high ITV (P = .0302). At the scheduled 3 months' follow-up visit, 33% of the low ITVs, 21% of the medium ITVs, and 5% of the high ITVs required an additional 3 months of healing.

CONCLUSION

In this study ITVs measured through surgical handpieces during implant placement provided meaningful real-time feedback that aided the surgeon regarding implant survival and determining unloaded healing times on a case-by-case basis.

Prospective clinical trial evaluating a new implant system for implant survival, implant stability and radiographic bone changes

BACKGROUND

There are a few prospective studies reporting on new implant systems. When a new implant is brought to market, prospective trials should be carried out to determine the predictability of that system.

PURPOSE

This prospective study evaluates implant survival, Resonance Frequency Analysis (RFA), and crestal bone level changes for a new implant system (Neoss System, Bimodal surface, Neoss Ltd, Harrogate, UK).

MATERIALS AND METHODS

Seventy-six patients, 38 females (age ranging from 23 to 57 years) and 38 males (ranging in age from 17 to 85 years) received 100 Neoss implants. Patients were consecutively enrolled in the study if they were missing one or more teeth in either arch, or a single tooth was scheduled for removal and immediate implant replacement. Evaluated implants were 4, 4.5, or 5 mm wide and were 7, 9, 11, 13, or 15 mm long. A one-stage approach was followed. At first stage and prior to healing abutment placement RFA measurements were taken. Measurements were retaken at second stage. Fifty-one implants were placed for restoration of single missing teeth and 49 were for short span implant bridges.

RESULTS

The cumulative survival rate at 1- to 2-year interval was 93%. Average initial RFA measurement for all implants was 72.06, while the average final score was 72.58. These changes were not statistically significant. Changes in RFA scores for maxillary implants were insignificant. Forty-two paired mandibular RFA measurements were evaluated. Initial and final mean mandibular RAF measurements were 73.65 (SD 9.203) and 77.186 (SD 6.177), respectively. These changes were statistically significant (p = .02). Sixty-four paired radiographs were available for evaluation. Between examinations, there was an average -0.6 mm of bone loss, which was statistically significant (p = .03). On average, 4.0-mm-wide implants lost 0.1 mm of bone when compared with 5-mm-wide implants. These differences were insignificant (p = .86). Bone loss was adjusted for implant length, and tooth position and there were small, but clinically insignificant changes. Five-millimeter-wide implants lose 0.2 mm more than 4.0-mm-wide implants (p = .7). Maxillary incisors lose the least amount of bone 0.152 (p = .33).

CONCLUSIONS

The implants tested in this study had initially high RAF readings, indicating good primary stability. RFA readings for implants placed in the mandible improved from baseline and the changes were statistically significant. Marginal bone levels revealed clinically insignificant bone loss from implant installation to second stage. Loss of seven implants with initially high RFA readings is surprising.

Anthropometric analysis of maxillary anterior buccal bone of Korean adults using cone-beam CT

PURPOSE

The aim of this study was to evaluate the thickness of buccal and palatal alveolar bone and buccal bony curvature below root apex in maxillary anterior teeth of Korean adults using Cone-beam CT images.

MATERIALS AND METHODS

The 3D image was reconstructed with dicom file obtained through CBCT from 20 - 39 year old Korean subjects (n = 20). The thickness of buccal and palatal plate, root diameter, the buccal bony curvature angle below root apex and the distance from root apex to the deepest point of buccal bony curvature were measured on maxillary anterior teeth area using OnDemand3D program.

RESULTS

Mean thickness of buccal plate 3 mm below CEJ was 0.68 ± 0.29 mm at central incisor, 0.76 ± 0.59 mm at lateral incisor, and 1.07 ± 0.80 mm at canine. Mean thickness of palatal plate 3 mm below CEJ was 1.53 ± 0.55 mm of central incisor, 1.18 ± 0.66 mm of lateral incisor, 1.42 ± 0.77 mm of canine. Bucco-lingual diameter 3 mm below CEJ was 5.13 ± 0.37 mm of central incisor, 4.58 ± 0.46 mm of lateral incisor, and 5.93 ± 0.47 mm of canine. Buccal bony curvature angle below root apex was 134.7 ± 17.5° at central incisor, 151.0 ± 13.9° at lateral incisor, 153.0 ± 9.5° at canine. Distance between root apex and the deepest point of buccal bony curvature of central incisor was 3.67 ± 1.28 mm at central incisor, 3.90 ± 1.51 mm at lateral incisor, and 5.13 ± 1.70 mm at canine.

CONCLUSION

Within the limitation of this study in Korean adults, the thickness of maxillary anterior buccal plate was very thin within 1mm and the thickness of palatal plate was thick, relatively. The buccal bony curvature below root apex of maxillary central incisor was higher than that of lateral incisor and canine and it seems that the buccal bony plate below root apex of central incisor is most curved.

Long-Term Results of Immediately Loaded Fast Bone Regeneration–Coated Implants Placed in Fresh Extraction Sites in the Upper Jaw

Recently, many authors have investigated the results of immediately loaded implants in fresh extraction sites, reporting favorable success rates, but only a few studies have included a long-term follow-up in the maxilla with analysis of clinical and radiographic data. The aim of this study was to evaluate the predictability of the immediate loading protocol with fast bone regeneration (FBR)-coated implants placed in postextractive sites in the maxilla, considering the success rate after at least 5 years of follow-up. Moreover, the clinical and radiographic results are evaluated in terms of soft tissue conditions and crestal bone loss values. One hundred fifty-eight implants were inserted following dental extraction in 70 consecutively operated patients. Each implant was immediately prosthesized. The data were collected before surgical planning, at the time of insertion, and after 3 and 5 years of occlusal loading. Specific success criteria were used to assess the success rate of immediately loaded postextraction implants. Clinical and radiographic examinations were used to determine long-term results. After a 5-year follow-up, 2 implants were lost, with a cumulative success rate of 98.7%. The radiographic and clinical data revealed well-maintained hard and soft tissues, with acceptable long-term results. The use of immediately loaded FBR-coated implants in fresh extraction sockets is shown to be a predictable technique if implants are inserted in selected cases and positioned with great care, following thorough preoperative analysis.