Immediate and Early Loading of Oxidized Tapered Implants in the Partially Edentulous Maxilla: A 1-Year Prospective Clinical, Radiographic, and Resonance Frequency Analysis Study

Do dental implants installed in different types of bone (I, II, III, IV) have different success rates? A systematic review and meta-analysis

Purpose

The objective of this systematic review and meta-analysis was to evaluate the survival rate of implants installed in bone type IV (Lekholm and Zarb, 1995) compared to that of implants installed in bone types I, II, and III.

Material and methods

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA) and was registered in the PROSPERO International Database of Systematic Reviews (CRD42021229775). The PubMed/MEDLINE, Scopus, and Cochrane databases were searched through July 2021. The PICO question was: "Dental implants installed in type IV bone have a lower success rate when compared to implants installed in type I bone, II and III?". The established inclusion criteria were: 1) controlled and randomized clinical trials (RCT), 2) prospective and retrospective studies with at least 10 participants with dental implants, and 3) patients with dental implants installed in bone tissue types I, II, III, and IV (Lekholm and Zarb, 1985). The minimum followup duration was 1 year.

Results

After searching the identified databases, 117 articles were selected for full reading and 68 were excluded. Thus, 49 studies were included for qualitative and quantitative analyses. The total number of participants included was 12,056, with a mean age of 41.56 years and 29,905 implants installed. Bone types I, II, and III exhibit a lower implant failure rate when compared to bone type IV.

Conclusion

Dental implants installed in bone types I, II, and III showed significantly higher survival rates than those installed in type IV. The bone type I success rate was not significantly different than that of type II; however, the success rate of bone type I and II was higher than that of type III.

Clinical effects of conventional and underprepared drilling preparation of the implant site based on bone density: A systematic review and meta-regression

PURPOSE

There is no clinical consensus to determine the right balance between underpreparation and marginal bone level changes. The purpose of this systematic review and meta-regression was to investigate the influence of the type of drilling preparation of the implant site in relation to the bone mineral density on the clinical success, expressed in terms of the MBL and implant failure rate.

STUDY SELECTION

A thorough search was performed using the digital databases MEDLINE PubMed, EMBASE, and Cochrane Central Register of Controlled Trials by entering research lines or various combinations of free words. The main keywords used were "dental implants", "bone density", and "torque".

RESULTS

The mean bone resorption in the conventional preparation group was -0.43 (± 0.28) mm, whereas it was -0.80 (± 0.37) mm in the underprepared group. For the D1/D2/D3 bone group, the slope was significantly different from zero and linearity; the D4 bone group slope was not significantly different from zero and was almost parallel, although it was significantly different from linearity. The box and whiskers plot shows that the MBL in underprepared sites tended to be significantly higher with a higher variation than that in conventionally prepared sites.

CONCLUSIONS

Within its limits, our meta-regression analysis showed that MBL is influenced by the type of drilling preparation and bone mineral density. In particular, a lower MBL was observed in the D1 bone with conventional preparation than with underpreparation. Moreover, a greater implant-to-osteotomy site mismatch was positively associated with greater MBLs in the bone densities of D1/D2/D3.

[Possibilities and prospects for experimental and clinical instrumentation techniques for determining the primary stability of dental implants in comparative analysis]

The high primary stability of dental implants provides a favorable prognosis for orthopedic treatment with implant-supported structures. The importance of assessing the stability and the bone tissue surrounding the implant as a whole is due to the fact that the process of osseointegration is a structural and functional connection between the bone and the loaded surface of the implant. Determination of the dynamics of the stability of dental implants allows timely monitoring of unpredictable changes at the stages of osseointegration and remodeling of bone tissue around the implant. Currently, in addition to clinical and radiation diagnostic methods, there are generally recognized by clinicians frequency resonance analysis and periotestometry. However, there are some scientific discrepancies indicating the lack of objectivity of these methods and the impossibility of their full-fledged application without the support of radiation and clinical diagnostic methods. In addition to these methods, there are many experimental and less common methods in clinical practice for assessing the primary stability of implants, but with reasonable objectivity. Thus, the reasons are given that for a full assessment of the relationship between the efforts exerted on implants and their movements in the space of bone tissue, devices are needed that reflect the stability and density of the contact of the implant with bone tissue in physical quantities. In particular, methods based on lasers, sound, quantitative ultrasound, and others have found experimental practical application. The ultrasound method of assessing the primary stability of the implant is estimated as the most promising, since it allows you to demonstrate the results of studies in certain physical quantities, as well as to compare these results with histomorphological indicators of osseointegration of dental implants.

Clinical Evaluation of Dental Implants with a Double Acid-Etched Surface Treatment: A Cohort Observational Study with Up to 10-Year Follow-Up

BACKGROUND AND OBJECTIVES

The main purpose of this study was to evaluate the survival and success rates of dental implants with a double acid-etched surface treatment with evaluation times up to 10 years post-loading. Materials and Methods: This study was conducted at a hospital oral surgery and implantology unit. It included 111 dental implants with a double acid-etched surface. Three groups were created: Group 1 (1-3 years loading), Group 2 (3-5 years loading), and Group 3 (over 5 years loading). Probing depth, resonance frequency analysis (ISQ value), and marginal bone loss were evaluated. Results: The data obtained underwent statistical analysis. Overall, 78 patients were included in the study, who received, in total, 111 dental implants, all replacing single teeth. Mean probing depth was 3.03 mm and mean ISQ was 65.54. Regarding marginal bone loss, in Group 1, 67.6% of implants did not undergo any thread loss, in Group 2, 48.3%, and in Group 3, 59.6%; 59.10% of all implants did not present thread loss with a mean bone loss of 0.552 mm. The implant survival rate was 99.1%, and the success rate was 96.37%. Conclusions: Implants with a double acid-etched surface showed excellent success rates in terms of marginal bone loss, ISQ, and probing depth after up to 10 years of loading, making them a clinically predictable treatment option. Future studies are needed to compare this implant surface with other types in different restorative situations.

The clinical significance of implant stability quotient (ISQ) measurements: A literature review

Implant stability quotients (ISQ values) are obtained in dental clinical practice on a non-invasive basis by resonance frequency measurement rapidly after surgical placement of implants. The ISQ-values are used as indicator for mechanical implant stability, and are believed to have predictive power for clinical outcome. It is the aim of this review to provide a synopsis of all factors described in the literature that influence ISQ measurements by performing an exhaustive literature review; moreover, this review aims at elucidating the key factors relevant for a rapid clinical predictive assessment. We searched systematically and exhaustively all major databases for publications relating to ISQ measurement methodology and for ISQ-influencing factor analyses. The reports identified were ordered in experimental (preclinical) studies and in clinical publications. We were able to identify 13 basic factors influencing ISQ-measurements. Among these, local bone quality, playing a key role in such measurements, was subdivided in four specific subfactors; thus a total of 17 individual factors was identified and reported to influence ISQ-measurements. A comprehensive list of these factors is provided in Table-form. A critical analysis points out that only 6 of these factors are of a sound predictive power useful for a rapid clinical assessment; and only two of these factors appear to have a well-documented scientific basis.

Accuracy Evaluation of 14 Maxillary Full Arch Implant Treatments Performed with Da Vinci Bridge: A Case Series

The use of pterygoid implants can be an attractive alternative to sinus bone grafting in the treatment of posterior atrophic maxilla. This technique has not been widely used because of the difficulty of the surgical access, the presence of vital structures, and the prosthetic challenges. The use of dynamic computer aided implantology (DCAI) allows the clinician to utilize navigation dental implant surgery, which allows the surgeon to follow the osteotomy site and implant positioning in real time. A total of 14 patients (28 pterygoid implants and 56 intersinusal implants) were enrolled in the study for a full arch implant prosthetic rehabilitation (4 frontal implants and 2 pterygoids implants), using a dynamic navigation system. The reported accuracy of pterygoid implants inserted using DCAI was 0.72 mm at coronal point, 1.25 mm at apical 3D, 0.66 mm at apical depth, and 2.86° as angular deviation. The use of pterygoid implants in lieu of bone grafting represents a valid treatment opportunity to carry out a safe, accurate, and minimally invasive surgery, while reducing treatment time and avoiding cantilevers for a full implant prosthetic rehabilitation of the upper arch.

Three-dimensional descriptive study of the pterygomaxillary region related to pterygoid implants: A retrospective study

The objective of this study was to analyze three-dimensionally the morphological characteristics of the pterygomaxillary region related to pterygoid implants. Volume, height, width and bone density were studied in relation to age, sex and dental status. This retrospective observational study analyzed the CBCT of 52 hemi-maxillas three-dimensionally (females n = 28, males n = 24; dentate = 31, edentulous = 21). Patients were exposed between September 2009 and October 2014, and data collection was performed between November 2015 and May 2016. Bone density, volume, height and width were analyzed in various locations of the maxilla and pterygoid process, and the variables age, gender and dental status patients were compared. The results show that the mean width of the pterygomaxillary joint was 7.5 mm (SD 1.00 mm), mean height was 12.51 mm (SD 1,82 mm) and mean volume was 321.7 mm³ (SD 142.02 mm³). Statistically significant differences between dentate and edentulous patients were found, showing a higher osseous density in dentate patients in the pterygoid process (758.2, SD 106.8, 95% CI 729.2 to 787.3 GSD - Gray Scale Density - compared to 689.9, SD 107.3, 95% CI 660.8 to 719.1 GSD; P = 0.022). In the maxilla, density was statistically significant lower in female subjects (571.0, SD 74.1, 95% CI 594.9 to 645.4 GSD) than in male subjects (620.2, SD 93.8, 95% CI 594.4 to 645.4 GSD, P = 0.047). In conclusion, due to the significant variation in the morphological characteristics of the pterygomaxillary region among subjects, personalized pre-surgical radiological assessment should always be performed. Gender, age and dental status are critical factors as they significantly affect bone density in this region.

Influence of Mucosal Thickness, Implant Dimensions and Stability in Cone Morse Implant Installed at Subcrestal Bone Level on the Peri-Implant Bone: A Prospective Clinical and Radiographic Study

The objective of this observational clinical study was to analyze the behavior of peri-implant tissues around cone Morse dental implants installed in the subcrestal bone position considering different clinical variables: Mucosal thickness, implant diameter, and implant length. Thirty patients were selected and included in the present study. Initially the thickness of the mucosa was measured by periapical radiographic and clinically (after the mucosal displaced). According to the planning for each treatment, implants with different dimensions (in length and diameter) were selected and used. Periapical radiographs were obtained at different times: Immediate postoperative (time t1) and 90 days after implantation (time t2). The initial stability of the implants (ISQ) was measured immediately of the implant insertion and 90 days after. The means and standard deviations of the ISQ values were in time t1 was 63.2 ± 6.99 (95% confidence interval (CI): 41 to 83) and in time t2 was 69.7 ± 7.09 (95% CI: 61 to 87). Overall mean of mesial and distal bone loss 90 days after the implantations were 1.11 ± 1.16 mm and 1.11 ± 1.15 mm, respectively. When the variables were considered, in all situations proposed, the bone loss showed differences statistically significant. In conclusion, the implant diameter and mucosal thickness variables showed an important effect on bone loss values. However, the implant length did not show an effect on the peri-implant behavior.

Predictive values of resonance frequency analysis as a diagnostic tool in palatal implant loss

OBJECTIVES

To determine the diagnostic value of resonance frequency analysis (RFA) in predicting palatal implant (PI) loss.

MATERIALS AND METHODS

RFA values of 32 patients (study center at Mainz and Dresden) were evaluated in a prospective randomized controlled trial addressing clinical performance of two loading concepts on PI (Orthosystem, Straumann, Basel, Switzerland). Group 1: conventional loading after a 12-week healing period vs group 2: immediate loading within one week after insertion. Stability was assessed by RFA after surgical insertion (T1), one week (T2), and 12 weeks (T3) later.

RESULTS

All 32 PI were clinically stable after surgical insertion; 14 PI were loaded conventionally and 18 immediately. One implant in group 1 was lost 6 weeks after insertion. One drop-out was registered in group 2. One false positive and three false negative implant stability quotients (ISQ) were observed. ISQ values of clinically stable PI in group 1 were 67.2 (SD ± 9.5) at T1, 62.3 (SD ± 11.7) at T2, and 68.2 (SD ± 5.5) at T3. Group 2 showed 67.1 (SD ± 11.7) at T1, 65.4 (SD ± 10.4) at T2, and 72.3 (SD ± 5.6) at T3. Differences between groups were not statistically significant for starting time (P = .88) and change from T1 to T2: 0.08 but were significant from T1 to T3: P = .04; (regression analysis).

CONCLUSIONS

RFA had no sensitivity for prediction of stability. General decrease after primary stability and increase with secondary stability gives support for specificity. Within the limits of the study, only the diagnostic value of RFA identifying stable palatal implants could be confirmed.

Immediate placement of tapered implants with a moderately rough anodized surface and smooth collar in fresh extraction sockets: A retrospective analysis with 10-year follow-up

BACKGROUND

There is limited long-term data on hard- and soft-tissue outcomes of implants immediately placed in postextraction sockets with immediate or early loading.

PURPOSE

To evaluate the clinical outcomes of immediately placed anodized tapered implants in consecutive patients with at least 10 years of follow up.

MATERIALS AND METHODS

This retrospective analysis evaluated outcomes of 61 consecutive patients who received 89 tapered implants with an anodized implant body and machined collar. Implants were placed in fresh extraction sites and functionalized using an immediate- or early-loading protocol. Outcome measures included survival, marginal bone level change (ΔMBL), and papilla index.

RESULTS

The 10-year cumulative survival rate was 100%. ΔMBL at the 10-year follow up was -0.86 ± 2.10 mm. At 10 years, patients had mesial and distal papilla index scores of 2 or 3 for 95.9% and 87.8% of implants, respectively.

CONCLUSIONS

When used for immediate placement and immediate- or early-loading protocols, this implant produced excellent long-term hard- and soft-tissue outcomes.

Preoperative evaluation of bone quality for dental implantation using an ultrasound axial transmission device in an ex vivo model

This study investigated the clinical utility of an ultrasound axial transmission device in preoperative evaluation of bone quality for dental implantation, by clarifying the relationship between cortical bone speed of sound (cSOS), insertion torque values (ITV), and implant stability quotient (ISQ) in porcine femur bone. Eleven fresh porcine femurs, without soft tissue, were prepared. The cSOS of these bones were measured using the axial transmission device. Bone mineral density (BMD) and porosity (Po) were measured in cortical bone samples obtained from the region of ultrasound measurements by X-ray microcomputed tomography. Thirty-three implants were inserted into these samples (three implants per bone sample), and ITV and ISQ were measured for all implants. Then, cortical bone thickness (CbTh) of the area for implantation was measured for all implants using a micrometer. The mean cSOS was 3962 m/s; mean BMD and Po were 0.822 g/cm2 and 0.185%, respectively. cSOS and BMD values were positively correlated, and cSOS values and Po values were negatively correlated. Mean ITV, ISQ, and CbTh were 37.95 Ncm, 71.172, and 2.869 mm, respectively. There was a positive correlation between cSOS values and ISQ values. The cSOS of each bone did not correlate with ITV for all of the bone samples. However, when the CbTh ranges from 3.0 to 3.5 mm, ITV are correlated with cSOS. These findings suggest that cSOS, which reflects the cortical bone quality, may be clinical utility as a preoperative diagnosis of the implant.

Long-Term Implant Survival After 100 Maxillary Sinus Augmentations Using Plasma Rich in Growth Factors

PURPOSE

To identify determinants of long-term implant survival after sinus augmentation procedure (SAP) using a combination of plasma rich in growth factors (PRGF) and graft material.

MATERIALS AND METHODS

Patients were included in this retrospective study if they underwent SAP through a lateral wall approach using PRGF in combination with mainly xenograft, and received implants restored for at least 1 year. Sociodemographic, behavioral and implant characteristics (clinical factors, implant details, surgical details, prosthesis details, and complications) were analyzed.

RESULTS

Sixty-seven patients received 217 implants in 100 augmented sinuses. The mean follow-up was 7.2 years. Overall, 22 implants failed in 15 patients (90% cumulative implant survival). Multivariable models showed greater implant survival with implants placed with ≥5 mm of residual crestal bone height (RBH) compared with those placed with <3 mm of RBH. There was also an improvement in survival comparing implant lengths. In addition, immediate loading of implants significantly increased the risk of implant failure.

CONCLUSION

The use of PRGFs for maxillary sinus grafting may be an effective and safe treatment option for the rehabilitation of atrophic edentulous posterior maxillae. However, randomized clinical trials are needed to confirm these findings.

Relationship between implant stability measurements obtained by insertion torque and resonance frequency analysis: A systematic review

BACKGROUND

The primary stability of dental implants can be evaluated by insertion torque (IT) and resonance frequency analysis (RFA).

OBJECTIVE

Assess the supposed relationship between the IT and RFA.

MATERIALS AND METHODS

A systematic review was performed based on the PRISMA. The electronic search was performed in the PubMed, Web of Science, SCOPUS, Cochrane Library electronic, OVID, and Scielo databases. Manual searches were also performed. There was no restrictions regarding year of publication or language. The articles identified were assessed independently by 3 trained researchers. Clinical trials reporting the RFA values by means of implant stability quotient (ISQ) and IT were included.

RESULTS

The electronic and manual searches yielded 2017 studies. Twelve studies were included in the systematic review. There was no statistically significant correlation between ISQ and IT (r_s  = .366; P = .079). The quality of the evidence was downgraded by risk of bias and indirectness; and the certainty of the evidence was low.

CONCLUSION

IT and RFA are independent and incomparable methods of measuring primary stability. Is important for clinicians to define only one method of evaluation for each implant.

Effect of the different implant protocols on peri-implant bone: a 6-month prospective study in beagle dogs

OBJECTIVE

To compare the effects of different implant placement and loading protocols on the marginal bone loss (MBL) in beagles by intraoral radiography.

METHODS AND MATERIALS

61 dental implants were inserted on 9 beagle dogs at bilateral lower posteriors according to 8 different protocols: immediate implant placement and immediate loading for 3 months (IIP + IL3) or 6 months (IIP + IL6) and unloading (IIP + UL), immediate implant placement and delayed loading for 3 months (IIP + DL3) or 6 months (IIP + DL6), delayed implant placement and immediate loading for 3 months (DIP + IL3) or delayed loading for 3 months (DIP + DL3) and unloading (DIP + UL). Intraoral radiography was performed to analyze the MBL during each surgery, before and after the implant placement and at 3-month intervals after the procedure.

RESULTS

In total, 57 samples were included. There was less MBL (p<0.05) in the IIP + IL3 group (1.22 ± 0.63 mm) compared to the DIP + IL3 group (1.89 ± 0.9 mm). The longer the loading time, the more bone loss appeared in the IIP + IL group; however, the results were reversed in the IIP + DL group. The MBL during the latter 3-month period was dramatically decreased compared to the former 3-month period in the IIP + DL3 group (p<0.05).

CONCLUSIONS

The IIP + IL group seems superior to the DL protocol and the MBL changed significantly during the first three months and thereafter became stable.

Relationship between implant stability on the abutment and platform level by means of resonance frequency analysis: A cross-sectional study

Resonance frequency analysis (RFA) has become the main tool used to assess the osseointegration of dental implants. The objective of this study was to verify the relationship between the ISQ values with different prosthetic abutments and with the implant platform. The hypothesis was that ISQ values changes according to the abutment height. Twelve patients were included, whose contribution to the study was 31 dental implants (external hexagon connection implants, 4.1x10 mm). The temporary implant-supported crown and prosthetic components were removed and the following smartpegs were inserted, one at a time: type 1, in the implant platform (G1); type A3, in the microunit component with 1mm transmucosal height (G2) and type A3, in the microunit component with 5mm transmucosal height (G3). In all the smartpegs, RFA measurements were taken on mesial, distal, buccal and lingual surfaces. All evaluations were performed by a single calibrated examiner (ICC = 0.989). Data were analyzed by Friedman and Spearman correlation tests and log-linear marginal regression (p<0.05). The mean age of participants was 52.83 (± 3.77) years. There was statistically significant difference (p<0.001) among the mean ISQ of G1 (88.27 ±5.70); G2 (72.75 ±4.73) and G3 (66.33 ±3.67). There was statistically significant negative correlation between the ISQ and the measurement distance (rs:-0.852; p<0.001; R2:0.553). Measurement distance was significantly associated (p<0.001) with ISQ value in the log-linear regression. The abutment height has a significant impact on resonance frequency analysis measurements. The higher the transmucosal abutment height, the lower the implant stability quotient value. Clinically, the ISQ measured on the abutment cannot be compared with values measured on the implant platform.

Clinical evaluation of the stability of implants placed at different supracrestal levels

PURPOSE

The aim of this study was to evaluate the stability during healing and before loading of implants placed at two different supracrestal levels according to their collar texture.

MATERIALS AND METHODS

This retrospective study included patients who received posterior implants with the same macro design. Implants with a machined collar were placed 0.3 mm above the crestal bone (M group), while those with a laser-microtextured collar were placed 1 mm above the crestal bone (L group). All implants healed in a single stage with healing abutments. Implant stability quotient (ISQ) values were determined using resonance frequency analysis immediately after implant placement during surgery and after 1, 4, 8, and 12 weeks after surgery. Other evaluated factors for stability included the implant diameter and length and the site of placement (maxilla or mandible).

RESULTS

In total, 103 implants (47 L, 56 M) were evaluated. The median ISQ values at baseline and 1 week after placement were significantly higher for the M group than for the L group (p=0.006 and p=0.031, respectively). There were no differences at the subsequent observation points. The ISQ value was higher for wide-diameter than regular diameter (p=0.001) and mandibular implants than maxillary implants (p=0.001 at 0-8. weeks; p=0.012 at 12 weeks) at all observation points. When diameter data were neglected, the implant length did not influence the ISQ value at all observation points.

CONCLUSION

Our results suggest that submerging implant more inside bone may only influence primary stability. Moreover, the implant diameter and site of placement influence primary and secondary stability before loading, whereas the implant length does not when its diameter is not accounted for.

Comparative study of immediate functional loading and immediate non-functional loading of monocortical implants

BACKGROUND

Attempts to shorten the overall length of treatment have focused on immediate loading, subsequent to implant placement. Prosthetic rehabilitation immediately after implant placement can be either functional or non-functional in nature. There is paucity of literature on the comparative evaluation of immediate functional and immediate non-functional loading of implants. This in-vivo study was undertaken to comparatively evaluate Immediate Functional Loading and Immediate Non-Functional Loading of monocortical implants with a follow-up period of 18 months.

METHODS

50 partially edentulous cases were selected for the study. The cases were divided into two groups. In first group (Group-1), 25 implants were subjected to immediate functional loading. In second group (Group-2), 25 implants were subjected to immediate non-functional loading. The crestal bone loss, clinical stability and degree of osseointegration of these two groups were comparatively evaluated.

RESULTS

The crestal bone loss in both groups was within acceptable limits. The implant stability, which is a reflection of the status of bone-to-implant interface, was comparable in both the groups at different time intervals. Although, the ISQ values in Group-2 were slightly higher than those in Group-1, the results were not statistically significant. Radiodensity indicating degree of osseointegration at different time intervals in both groups was also comparable.

CONCLUSION

Both the IFL and INFL protocols can be undertaken satisfactorily in rehabilitation using endosseous implants; however, the main factors for success in IFL and INFL are case selection, meticulous treatment planning and the precision of technique.

Marginal bone level changes and implant stability after loading are not influenced by baseline microstructural bone characteristics: 1-year follow-up

OBJECTIVE

The aim of this study was to investigate the influence of different bone tissue characteristics of implant sites on changes in marginal bone level and implant stability over time.

MATERIAL AND METHODS

One hundred and one implants were inserted in 41 patients. Cortical bone thickness of the alveolar ridge was measured on computed tomography (CT) images. Histomorphometric and microtomographic analyses (microCT) were performed in bone specimens obtained by using a trephine bur, at first drilling. Implant stability quotient (ISQ) measured by resonance frequency analysis (RFA) was registered at implant insertion. Implant stability quotient was measured also at the stages of uncovering, loading and at the 1-year follow-up, when standardized periapical radiographs were taken to measure the marginal bone level (MBL). Descriptive statistics, Spearman's rho correlation and multiple linear regression were used for data analysis (P < 0.05).

RESULTS

Comparison between groups of higher and lower values of ISQ changes and between groups of higher and lower values of MBL changes revealed no differences in histomorphometric and microtomographic parameters, according to non-parametric comparison tests, (P > 0.05). Bivariate correlation also showed no association among these microstructural parameters and the outcomes evaluated. There was no correlation between cortical thickness and MBL changes (r = -0.029; P = 0.832) and between cortical thickness and ISQ changes (r = 0.145; P = 0.292).

CONCLUSION

Microstructural bone characteristics of implant sites have no effect on changes in marginal bone level and implant stability as measured by RFA. Bone morphology cannot predict implant treatment success over time.

Does the time of osseointegration in the maxilla and mandible differ?

OBJECTIVES

The objectives of the present study were to measure the implant stability quotient (ISQ) values at 3 different time points after the surgical insertion and to determine whether the time of osseointegration differs in the maxilla and mandible.

MATERIALS AND METHODS

To measure implant stability, resonance frequency analysis (RFA) was performed in 44 patients (40 women, 4 men) with a total of 100 Implacil De Bortoli implants; the patients were divided into 2 groups: group 1, implants in the maxilla (22 in the anterior maxilla and 37 in the posterior maxilla); and group 2, implants in the mandible (41 posterior mandibles). Using RFA, implant stability was measured immediately after implant placement to assess the immediate stability (time 1) and at 90 (time 2) and 150 (time 3) days.

RESULTS

Overall, the mean (SD) ISQ was 63.3 (6.63) (95% confidence interval [CI], 39-79) for time 1, 70.5 (6.32) (95% CI, 46-88) for time 2, and 73.5 (6.03) (95% CI, 58-88) for time 3. In group 1, the mean (SD) ISQ was 61.8 (6.56) (95% CI, 39-79) for time 1, 68.8 (5.19) (95% CI, 57-83) for time 2, and 72.3 (5.91) (95% CI, 58-85) for time 3. In group 2, the mean (SD) ISQ was 65.5 (6.13) (95% CI, 44-75) for time 1, 72.9 (7.02) (95% CI, 46-88) for time 2, and 75.3 (5.80) (95% CI, 60-88) for time 3.

CONCLUSIONS

The stability of the implants placed in the maxilla and mandible showed a similar evolution in the ISQ values and, consequently, on osseointegration; however, the implants in the mandible presented superior values at all time points.

Implant stability change and osseointegration speed of immediately loaded photofunctionalized implants

OBJECTIVES

This study evaluated the degree and rate of implant stability development for photofunctionalized dental implants in humans.

MATERIALS AND METHODS

Thirty-three implants (7 patients) placed in the maxilla and immediate loaded were evaluated. Photofunctionalization was performed by treating implants with ultraviolet for 15 minutes immediately before placement. Implant stability was assessed by measuring the implant stability quotient (ISQ) weekly starting from implant placement up to 3 months. Osseointegration speed index (OSI), defined as ISQ increase per month, was also evaluated.

RESULTS

The average ISQ for photofunctionalized implants at week 6 was 78.0, which was considerably higher than the average ISQ of 66.1, reported in literature for various as-received implants after a longer healing time of 2 to 6 months. No stability dip was observed for photofunctionalized implants regardless of the initial ISQ values. The OSI for photofunctionalized implants was 6.3 and 3.1 when their initial ISQ was 65 to 70 and 71 to 75, respectively, whereas the OSI values for as-received implants calculated from literature ranged from -3.0 to 1.17 with an average of -0.10.

CONCLUSIONS

Photofunctionalization accelerated and enhanced osseointegration of dental implants, providing novel and practical avenues for further advancement in implant therapy.

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.

Influence of Glycemic Control on Peri-Implant Bone Healing: 12-Month Outcomes of Local Release of Bone-Related Factors and Implant Stabilization in Type 2 Diabetics

BACKGROUND

The poor glycemic status seems to be an important factor affecting implant complication rates, including peri-implant bone loss.

PURPOSE

This trial evaluated the influence of glycemic control of type 2 diabetes mellitus (T2DM) patients on implant stabilization and on the levels of bone markers in peri-implant fluid during the healing.

MATERIALS AND METHODS

Systemically healthy patients (SH,n = 19), better-controlled T2DM (BCDM,n = 16), and poorly controlled T2DM (PCDM,n = 16) indicated for implant therapy were recruited. The implant stability quotient (ISQ) was determined at implant placement, 3, 6, and 12 months. Levels of transforming growth factor- β (TGF-β), fibroblast growth factor (FGF), osteopontin (OPN), osteocalcin (OC), and osteoprotegerin (OPG) in the peri-implant fluid were quantified at 15 days, and 3, 6, and 12 months, using the Luminex assay.

RESULTS

OPG and OPN levels were higher in SH at 12 months than at15 days (p < .05), whereas OC and TGF-β were lower in PCDM at 12 months compared with the 15-day and 3-month follow-ups, respectively (p < .05). Inter-group analyses showed lower OPN levels in PCDM compared with SH at 12 months (p < .05). The ISQ was higher at 12 months when compared with baseline and 3 months in SH (p < .05), whereas no differences were observed during follow-up in diabetics, regardless of glycemic control (p > .05). No difference in ISQ was observed among groups over time (p > .05).

CONCLUSION

Poor glycemic control negatively modulated the bone factors during healing, although T2DM, regardless of glycemic status, had no effect on implant stabilization.

Bone Response and Soft Tissue Changes Around Implants With/Without Abutments Supporting Fixed Partial Dentures: Results From a 3-Year, Prospective, Randomized, Controlled Study

BACKGROUND

Diverging opinions exist regarding rough surface abutment usage, and abutment exclusion effects are unstudied.

PURPOSE

The study aims to: (1) assess tissue response to oxidized or machined abutments or no abutment; and (2) evaluate immediate implant-loading effects.

MATERIALS AND METHODS

In a 2005-2008 parallel-group randomized, clinical trial, 50 partially edentulous subjects received three Brånemark TiUnite™ (Nobel Biocare®, Gothenburg, Sweden) implants. Superstructures were attached via abutments (one with a TiUnite surface - AOX, and one with a machine-milled surface - AM) or directly at implant level (IL). Implants were immediately loaded (test) or unloaded for 3 months (control). Postoperative examinations were done up to 3 years.

RESULTS

Forty-seven subjects were reexamined after 3 years. Four and two implants were lost in test and control groups, respectively, during the first year. Thereafter, no implant loss occurred (95.7% survival). After 1 year, mean (SEM) peri-implant marginal bone loss (MBL) was 1.33 (0.08) mm (test) and 1.25 (0.08) mm (control). Between 1 and 3 years, a nonsignificant MBL occurred: 0.36 (0.08) mm (test) and 0.33 (0.06) mm (control). Similar MBL was found at IL (1.81 [0.93] mm) and AOX (1.77 [0.14] mm) after 3 years and was significantly lower at AM (1.42 [0.17] mm) than at IL (groups merged); 42% of the implants displayed mucosal bleeding at 3 years and probing pocket depths varied between 2.13 (0.12) mm and 3.62 (0.15) mm, significantly lower buccally. Bleeding on probing (BoP) in minute amounts was found in 30-45% of the sites and abundant BoP at about 20% of the sites. Soft tissue retracted mostly during year 1 and was more pronounced buccally. Regression analyses revealed significant effects from smoking, periodontal disease, abundant BoP, and a low initial implant stability quotient on MBL.

CONCLUSIONS

No further significant MBL was found between 1 and 3 years, irrespective of loading protocol. Use of machined abutments may benefit marginal bone stability over time.

Does Implant Design Affect Implant Primary Stability? A Resonance Frequency Analysis-Based Randomized Split-Mouth Clinical Trial

The purpose of this study was to assess implant stability in relation to implant design (conical vs. semiconical and wide-pitch vs narrow-pitch) using resonance frequency analysis. Twenty patients with bilateral edentulous maxillary premolar region were selected. In one hemiarch, conical implants with wide pitch (group 1) were installed; in the other hemiarch, semiconical implants with narrow pitch were installed (group 2). The implant allocation was randomized. The implant stability quotient (ISQ) was measured by resonance frequency analysis immediately following implant placement to assess primary stability (time 1) and at 90 days after placement (time 2). In group 1, the mean and standard deviation ISQ for time 1 was 65.8 ± 6.22 (95% confidence interval [CI], 55 to 80), and for time 2, it was 68.0 ± 5.52 (95% CI, 57 to 77). In group 2, the mean and standard deviation ISQ was 63.6 ± 5.95 (95% CI, 52 to 78) for time 1 and 67.0 ± 5.71 (95% CI, 58 to 78) for time 2. The statistical analysis demonstrated significant difference in the ISQ values between groups at time 1 (P = .007) and no statistical difference at time 2 (P = .54). The greater primary stability of conical implants with wide pitch compared with semiconical implants with narrow pitch might suggest a preference for the former in case of the adoption of immediate or early loading protocols.

Immediate loading: from biology to biomechanics. Report of the Committee on Research in fixed Prosthodontics of the American Academy of fixed Prosthodontics

One of the key issues of modern implant rehabilitation is the overall shortening of treatment time. High survival rates for immediately loaded implants have been reported in many but not all treatment modalities. In recent years, considerable evidence for the successful immediate loading outcome has been documented in both animal and human studies. The mechanical force generated by immediate loading may explain the favorable biologic response of bone and surrounding tissue when the design is biomechanically sound. However, in certain treatment modalities, including but not limited to immediately placed maxillary anterior single implants, immediately placed single molar implants, unsplinted implants in overdentures, and implants in maxillary anterior partial fixed dental prostheses, loading dental implants indiscriminately and immediately is not safe because of potentially unfavorable stress distribution and a negative cellular response under such high stress during early healing.

Implants placed in sites of previously failed implants: a systematic review

PURPOSE

The aim of this study was to systematically review the literature on implant placement in sites of previously failed implants and to assess survival and success rates of the replacement implants to investigate the effectiveness of the procedure.

MATERIALS AND METHODS

MEDLINE and Cochrane Oral Health Group databases were used to identify articles published between 1985 and 2011. Six articles were selected for a total of 334 patients (338 implants).

RESULTS

The survival rate ranged from 71% to 100%. The survival rate for implants placed for the second time (third attempt) in the sites of previously failed implants was 83.75%. No studies included in this review reported the cumulative success rate except for the prospective one, which reported a 93.7% success rate. The main limitations of the present systematic review have been the scarce number of patients and implants in the analyzed studies and the lack of large well-designed case-control long-term trials.

CONCLUSIONS

Survival rates of implants placed in the areas of previously failed implants are low, although they should not discourage clinicians from a second or even a third attempt.

Early loading of hydrophilic titanium implants inserted in low-mineralized (D3 and D4) bone: one year results of a prospective clinical trial

Introduction

Pure titanium is the material of choice for contemporary dental implants. However, superficial reaction of the moderately rough titanium surface with atmospheric components decreases its hydrophilicity. INICELL® represents a chemical alteration and hydrophilization of a moderately rough i. e. sand-blasted and acid-etched titanium surface. The hydrophilicity leads to a more homogenous adsorption of proteins on the implant surface in-vitro, supporting the activation of a higher number of platelets and the generation of a homogenous, complete fibrin matrix in the early phases of osseointegration. This in turn helps to reduce the healing time and enhances the predictability of osseointegration in compromised bony situations.

The objective of this case series trial was therefore to investigate if early loading (after 8 weeks) of hydrophilic INICELL implants is feasible in patients with reduced bone quality.

Methods

In 10 patients, 35 hydrophilic implants were placed in sites revealing bone quality class 3 and 4, and uncovered after 4 weeks. Eight weeks later implants were released for loading if the tactile resistance was ≥35 Ncm. Lower resistances resulted in 12 weeks initial healing period. Insertion torque, ISQ, tactile resistance and vertical bone level were evaluated at implant installation, after 4 weeks (uncovering), 8 or 12 weeks (loading), and 12 weeks and one year after loading.

Results

Mean implant insertion torque was 21 Ncm. 31 (88.6%) showed a tactile resistance of >35 Ncm after eight weeks and were released for prosthetic loading. Eight weeks after insertion, one implant (2.9%) had to be removed following a soft tissue complication. One implant had to be removed after 4 weeks due to a technical complication (fractured Osstell-abutment), it was therefore excluded from the analysis.

33 of 34 implants (97%) were loaded to occlusion and were in situ/functional one year after implantation. ISQs increased from 43 at baseline to 63 at eight weeks, and 72 at three months after loading. Then, ISQ remained constant until one year after loading.

Conclusions

Within the limitations of this prospective case series, hydrophilic implants may allow for shortening of the initial healing period even in bone with compromised density.

Clinical analysis of the stability of dental implants after preparation of the site by conventional drilling or piezosurgery

We used resonance frequency analysis to evaluate the implant stability quotient (ISQ) of dental implants that were installed in sites prepared by either conventional drilling or piezoelectric tips. We studied 30 patients with bilateral edentulous areas in the maxillary premolar region who were randomised to have the implant inserted with conventional drilling, or with piezoelectric surgery. The stability of each implant was measured by resonance frequency analysis immediately after placement to assess the immediate stability (time 1) and again at 90 days (time 2) and 150 days (time 3). In the conventional group the mean (SD) ISQ for time 1 was 69.1 (6.1) (95% CI 52.4-77.3); for time 2, 70.7 (5.7) (95% CI 60.4-82.8); and for time 3, 71.7 (4.5) (95% CI 64.2-79.2). In the piezosurgery group the corresponding values were: 77.5 (4.6) (95% CI 71.1-84.3) for time 1, 77.0 (4.2) (95% CI, 69.7-85.2) for time 2, and 79.1 (3.1) (95% CI 74.5-87.3) for time 3. The results showed significant increases in the ISQ values for the piezosurgery group at each time point (p=0.04). The stability of implants placed using the piezoelectric method was greater than that of implants placed using the conventional technique.

A comparative analysis of periimplant bone levels of immediate and conventionally loaded implants

BACKGROUND

With the trend of shortening the treatment time and reducing patient discomfort/inconveniences immediate loading of implants has emerged as an alternative approach for replacing missing natural teeth. The aim of this study is to evaluate and compare the effectiveness of immediate implant loading protocol over conventional implant loading protocol in partially edentulous mandible.

METHODS

Twenty patients were selected from out patients department who needed the replacement of one of the missing mandibular first molar. They were divided into two groups. In Group A patients implants were loaded with immediate implant loading protocol, whereas in Group B they were loaded with conventional loading protocol. Periimplant bone loss and soft tissue health were measured and compared using OPG and IOPA radiographs 06 and 12 months after implant placement.

RESULTS

One implant failed in immediate loading group (Group A), whereas all implants survived in conventional loading group (Group B). The average periimplant bone loss after 6 months and 1 year for Group A were 0.69 mm and 1.09 mm respectively, whereas it was 0.74 mm and 1.13 mm respectively for Group B. The difference in the bone loss between Group A and B was not statistically significant.

CONCLUSION

Immediate implant loading protocol has a highly acceptable clinical success rate in partially edentulous lower jaw although implant survival rate is slightly inferior to conventional loading protocol.

10-year follow-up of immediately loaded implants with TiUnite porous anodized surface

BACKGROUND

The immediate loading of implants with a porous anodized surface is a well-described technique. Few data are however available on the long-term outcomes.

PURPOSE

The aim of this prospective study was to assess the 10-year performance of TiUnite implants supporting fixed prostheses placed with an immediate loading approach in both postextractive and healed sites.

MATERIALS AND METHODS

All patients received a fixed provisional restoration supported by immediately loaded parallel design, self-tapping implants with a porous anodized TiUnite surface, and an external-hexagonal connection. Both healed and postextractive cases were included. Success and survival rate for restorations and implants, changes in marginal peri-implant bone level, probing depth measurements, biological or technical complications, and any other adverse event were recorded at yearly follow-up up to 10 years after surgery.

RESULTS

A total of 210 implants fulfilled the inclusion criteria and were consecutively placed in 59 patients. Forty-seven (22.38%) implants were lost because of the recalled patient refused to attend the planned 10-year follow-up. Five over 210 (2.38%) implants were lost. At the final follow-up, the accumulated mean marginal bone loss and probing depth were, respectively, 1.93 mm (SD 0.40) and 2.54 mm (SD 0.44) for the implants placed in healed sites (n = 84); 1.98 mm (SD 0.37) and 2.63 mm (SD 0.39) for the implants placed in postextractive sites (n = 74). The restorations examined achieved a cumulative 65.26% success rate and 97.96% survival rate. The implants placed in healed and postextractive sites, respectively, achieved a 98.05% and a 96.52% cumulative survival rate.

CONCLUSIONS

Positive results in terms of bone maintenance in the long-term perspective are to be expected using immediately loaded implants with a TiUnite porous anodized surface in both postextractive and healed sites when adequate levels of oral hygiene are kept.