Minimally invasive treatment of the atrophic posterior maxilla: A proof-of-concept prospective study with a follow-up of between 36 and 54 months

Closed sinus lift and fixed prostheses versus implant-assisted overdentures in management of atrophied distal extension maxillary ridges: A one-year randomized clinical trial

STATEMENT OF PROBLEM

Rehabilitation of elderly or medically compromised patients with an atrophied unilateral posterior maxillary ridge by an implant-supported prosthesis may be complicated by maxillary sinus pneumatization with insufficient bone for implant placement.

PURPOSE

This short-term clinical trial assessed clinical results of closed sinus lift and fixed prosthesis versus implant-assisted overdentures in the management of participants with atrophied distal extension maxillary ridges.

MATERIAL AND METHODS

Forty participants with unilateral atrophying distal extension maxillary ridges were randomly assigned into 2 groups. The CSL group (n=20) participants received fixed prostheses supported by 3 implants following a closed sinus lift. The IOD group (n=20) participants received removable partial overdentures assisted by a single implant that was positioned mesially to the maxillary sinus. The modified plaque index (MPI), modified gingival index (MGI), pocket depth (PD), implant stability (IS), and vertical bone loss (VBL) were measured at prosthesis delivery (T0), and 6 (T6) and 12 months (T12) after delivery. The oral health impact profile (OHIP-14) questionnaire was used to assess oral health-related quality of life (OHRQoL) at T12. Significant differences between observation times were performed using Friedman and Wilcoxon signed-rank tests for MPI and MGI and using repeated measures ANOVA with Bonferroni correction of P values for PD, IS, VBL, and OHIP. Between-group comparison of MPI and MGI the Mann-Whitney test was used, while for PD, IS, VBL, and OHIP comparison was made using independent samples t test (α=.05 for all tests).

RESULTS

The implant survival rates were 100% for both groups. MPI and PD significantly increased with time for both groups. MGI significantly increased with time for the CSL group only (P=.049). The IS significantly decreased with time for the IOD group. VBL increased significantly from T6 to T12 for the CSL (P=.042) and the IOD (P=.002) groups. The CSL group recorded higher MPI, MGI, PD, and IS values than the IOD group (P<.05). The IOD group recorded higher VBL than the CSL group (P<.001). The CSL group scored significantly lower OHIP-14 values (better OHRQoL) than the IOD group for all values (P<.05).

CONCLUSIONS

In comparison with implant-assisted partial overdentures, closed sinus lift with fixed prostheses had higher implant stability, reduced bone loss, and higher participant OHRQoL. However, peri-implant soft tissue health was found to be better with implant overdentures.

Analysis of ultra-short implants with different angulations: a retrospective case-control study with 2 to 9 years of follow-up

OBJECTIVES

Does the angulation of ultrashort implants influence the stability of the peri-implant bone? The present study aimed to evaluate the effectiveness of non-axial ultrashort implants after 2 to 9 years of follow-up in resorbed alveolar ridges.

MATERIALS AND METHODS

All partially edentulous patients with ultrashort implants (< 6 mm) used in the posterior region of an atrophic mandible or maxilla, to support partial dentures in conjunction with standard implants, were included in this study. Peri-implant bone loss, success and survival rates, crestal bone levels, crown-to-implant ratio and implant angulation were measured for each implant. Implants were divided into two groups: straight implants with angulation < 17° (control group) and tilted implants with angulation > 17° (test group). Statistical analysis was used to find any significant differences between the two study groups and to investigate significant linear correlations among all the variables (p = 0.05).

RESULTS

A total of 42 ultrashort implants with a mean of 4 years of follow-up were included: 20 ultrashort axially loaded implants and 22 tilted implants. Mean crestal bone levels from baseline loading to maximum follow-up did not reveal statistical differences in regard to PBL; mean success and survival rates were 100% in all groups.

CONCLUSIONS

PBL, success and survival rates of axial ultrashort implants and tilted ultrashort implants are comparable to those of conventional implants.

CLINICAL RELEVANCE

This retrospective study revealed that ultrashort implants, even when placed with an angulation > 17°, can safely be used to support partial fixed prostheses. Further prospective clinical studies with larger samples and prospective design are needed to confirm these findings.

The Impacted Maxillary Canine in the Adult: A Narrative Review and Implant Treatment Options

PURPOSE

The purpose of this article is to provide clinicians with options to restore the adult patient with an impacted maxillary canine using dental implants. Literature was reviewed to provide evidence for the methods suggested.

METHODS

The search strategy utilized pubmed.gov to identify articles pertinent to identified treatment options. The search used terms which included dental implants and impacted tooth, tilted implants and fixed partial prostheses, 6 mm dental implants, and 4 mm dental implants. Articles were included if they reported dental implant procedures associated with impacted canines in adults, or if they reported on the use of tilted implants, immediate implant placement at time of canine removal, or the use of short implants. Articles with less than 12 months follow up were excluded.

RESULTS

The search identified articles which included dental implants and impacted tooth (n = 142), tilted implants and fixed partial (n = 36), 6 mm dental implants (n = 182), and 4 mm dental implants (n = 162). From this search, 28 articles were collated that satisfied the inclusion criteria. The use of tilted implants had success rates ranging from 93% to 99%. Short implants had success rates ranging from 87 to 90% in the posterior maxilla. Immediate implant placement after removal of the impacted canine lacked long term reports. Two cases are included to demonstrate treatment planning using navigation to guide implant placement in an adult patient with an impacted maxillary canine.

CONCLUSIONS

The evidence-based literature concerning implant placement associated with adult maxillary canines is limited. There is evidence to support tilting implants to avoid the impacted canine, or the use of short implants splinted together to avoid the impacted tooth. Other options had insufficient data to offer support.

Guided Dental Implant Surgery: Systematic Review

Among the common procedures in clinical practice in the field of dentistry is prosthetic rehabilitation through the insertion of dental implants. In order to obtain the best aesthetic and functional results, the oral surgeon who deals with implantology must be able to position the dental implants correctly; a crucial role is therefore played by the diagnostic and treatment planning phases, where attention must be paid to anatomical constraints and prosthetic constraints in the alveolar bone site. The parameters, such as bone quality, bone volume, and anatomical restrictions, can be processed and simulated using implant planning software. The simulation of the virtual positioning of the implant can lead to the construction of a three-dimensional model of the implant positioning guide, which can be used during the implant surgery. The aim of this systematic review is to evaluate survival rates, early and late failure rates, peri-implant bone remodeling, and possible implant-prosthetic complications related to implants placed using digitally designed surgical guides. This systematic review was written following the indications of PRISMA and envisaged the use of 3 databases: Scopus, PubMed, and Cochrane Library. Results: Only 9 of the 2001 records were included, including 2 retrospective studies and 7 prospective studies. Conclusion: On the basis of the studies selected in this review, it can be seen that the implant survival obtained with the use of guided implant surgery shows high percentages. Many recorded failures occurred early, due to a lack of osseointegration, and the variables that come into play in the survival of the implants are many.

Impact of tilted implants for implant-supported fixed partial dentures: A systematic review with meta-analysis

STATEMENT OF PROBLEM

The use of tilted implants has been considered a suitable option for completely edentulous patients. However, consensus on their clinical performance is lacking, specifically for partial rehabilitation.

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate the marginal bone loss and implant survival rate of tilted implants compared with those of axial implants for implant-supported fixed partial dentures (ISFPDs).

MATERIAL AND METHODS

A systematic search of the MEDLINE/PubMed, Web of Science, Embase, Cochrane, and ProQuest databases and reference lists for articles published until May 2022 was performed by 2 independent reviewers without language or publication date restrictions. A meta-analysis was performed using the RevMan version 5.4 program. Quality assessments were performed using the Newcastle-Ottawa scale.

RESULTS

Nine studies were included, totaling 258 participants and 604 implants (269 tilted implants and 335 axial implants). No significant differences were found between the tilted and axial implants for the implant survival rate (P=.81; risk ratio: 1.14). However, higher marginal bone loss values were observed for tilted implants (P=.001; mean difference: 0.12 mm). No significant heterogeneity was observed in either analysis.

CONCLUSIONS

No significant relationship was found between tilted and axial implants for ISFPD rehabilitation. However, tilted implants presented greater risks of marginal bone loss than axial implants.

Clinical Outcomes of Dental Implants with Two Different Internal Connection Configurations—A RCT

Background: The aim of the present study was to highlight clinical and radiographical differences among implants sharing the same macro-geometry but with two different prosthodontic connections. Methods: Patients requiring at least 2 implants in the posterior area of the jaw were randomly divided into two groups (Conical (CS) and Internal Hexagonal (IH) connection). At implant surgery (T0), insertion torque, implant stability quotient (ISQ values recorded by resonance frequency analysis, RFA), and soft tissue thickness (STH) were assessed. A 1-abutment/1-time protocol was applied, and the prosthesis was realized following a fully digital workflow. At the 36-month follow-up periapical x-rays were taken. In order to statistically analyse differences among the two groups and the different variables, paired T-test was used. Linear regression analysis was conducted to analyze how marginal bone loss (MBL) was affected by other independent variables. A neural network created to predict the success (good or not good) of the implant itself was implemented. Results: 30 out of 33 patients (14 males, 16 females, mean age: 68.94 ± 13.01 years) (32 CS and 32 IH) were analyzed. No implants failed. Marginal bone loss at the 3-year time-point was 0.33 ± 0.34 mm and 0.43 ± 0.37 mm respectively for CS and IH with a significant difference between the two groups (p = 0.004). The presence of keratinized gingiva (p = 0.034) significantly influenced MBL. Conclusions: Both the implant connections investigated presented optimal clinical outcomes with minimal marginal bone loss; however, CS implants and implants with the presence of a greater width of keratinized tissue presented significantly lower MBL.

Tilted Implants and Sinus Floor Elevation Techniques Compared in Posterior Edentulous Maxilla: A Retrospective Clinical Study over Four Years of Follow-Up

The aim of this study was to evaluate the implant survival rate, marginal bone loss, and surgical and prosthetic complications of implants placed through sinus floor elevation and tilted implants engaged in basal bone to bypass the maxillary sinus. Sixty patients were enrolled for this study. According to the residual bone height of the posterior maxilla, the sample was divided into three groups of 20 patients: Group A (lateral sinus floor elevation), Group B (transcrestal sinus floor elevation), and Group C (tilted implants employed to bypass the sinus floor). Follow-up visits were performed one week after surgery, at three and six months, and then once a year for the next 4 years. The outcomes were the implant survival rate, marginal bone loss, and surgical and prosthetic complications. Although Groups A, B, and C demonstrated implant survival rates of 83.3%, 86.7%, and 98.3%, respectively, the statistical analysis showed no statistically significant difference between groups. Statistically significant differences between groups were also not found concerning marginal bone loss, as recorded by intra-oral X-ray measurements during follow-up examinations. Regarding complications, it was not possible to perform a statistical analysis. To reduce possible surgical risks, implant placement in basal bone could be preferred.

Within-patient evaluation of chewing efficiency and maximum bite force of conventional dentures, fixed prostheses, and milled bar overdentures used for All-on-4 implant rehabilitation of atrophied mandibular ridges: A short-term randomized trial

PURPOSE

This crossover study aimed to evaluate chewing efficiency and maximum bite force (BF) of conventional dentures, fixed prostheses, and milled bar overdentures (MO) used for All-on-4 implant rehabilitation of atrophied mandibular ridges.

METHODS

Sixteen edentulous participants with resorbed mandibular ridges received new conventional dentures (CD, control). Four implants were inserted after 3 months in the mandible using the All-on-4 protocol and loaded immediately with acrylic prosthesis. In a crossover manner, each patient had either fixed restoration (FR, 12 occlusal units) or MO (14 occlusal units) randomly in a crossover study design. Chewing efficiency was evaluated using the mixing ability test. The hue deviation (HD) of two-colored gum was calculated after being chewed for 5, 10, 20, 30, and 50 masticatory cycles. Maximum BF was evaluated using a BF device. HD and BF were measured after using CD, FR, and MO prostheses.

RESULTS

For all groups, the highest HD (i.e., the lowest chewing efficiency) was noted with 5 strokes, followed by 10, 20, 30 strokes, and the lowest HD (i.e., the highest chewing efficiency) was noted with 50 strokes. For all number of chewing strokes, CD showed the highest HD, then FR, and MO recorded the lowest HD. The highest BF was observed with MO, then FR, and the lowest BF was noted with CD.

CONCLUSION

Within the limitations of this short-term investigation, both FR and MO used for All-on-4 implant rehabilitation of patients with resorbed mandibular ridges improve masticatory efficiency and maximum BFs compared to CD. However, MO was associated with significantly higher chewing efficiency and maximum BFs than fixed prosthesis.

Atrophic Maxilla Rehabilitation Through Dental Implants Using the V-4 Strategy Associated With Guided Surgery: A Case Report and Technique Description

Atrophic maxilla rehabilitation through dental implants is always a challenging procedure. However, alternative approaches such as guided surgery and the installation of short implants are progressively supplanting more invasive bone regeneration procedures. A V-4 technique described in 2016 facilitates the installation of dental implants in patients with atrophic maxilla; however, its authors recommend incision, flap opening, and elevation of the anterior area of the maxillary sinuses. This case report describes a less invasive proposal for modifying the technique through the association of guided surgery, which improves implant placement accuracy, shortens surgical time, and reduces morbidity.

Comparison between computer-guided and freehand dental implant placement surgery: A systematic review and meta-analysis

The purpose of this systematic review was to compare computer-guided (fully guided) and freehand implant placement surgery in terms of marginal bone loss, complications, and implant survival. This review followed the PRISMA guidelines and was registered in the PROSPERO database (CRD42019135893). Two independent investigators performed the search of the PubMed/MEDLINE, Scopus, and Cochrane Library databases for studies published up to April 2020 and identified 1508 references. After a detailed review, only four studies were considered eligible. These studies involved a total of 154 patients with 597 dental implants and a mean follow-up period of 2.25 years. There was no difference between computer-guided surgery and freehand surgery in terms of the marginal bone loss (mean difference -0.11mm, 95% confidence interval (CI) -0.27 to 0.04mm; P=0.16), mechanical complications (risk ratio (RR) 0.85, 95% CI 0.36-2.04; P=0.72), biological complications (RR 1.56, 95% CI 0.42-5.74; P=0.51), and implant survival rate (RR 0.53, 95% CI 0.11-2.43; P=0.41). This meta-analysis demonstrated that both computer-guided and freehand surgeries yielded similar results for marginal bone loss, mechanical and biological complications, and implant survival rate.

[Development of tilted implant for free end of maxillary posterior teeth]

Vertical bone insufficiency in the maxillary posterior teeth is a common clinical situation. At present, the bone insufficiency in the maxillary posterior teeth is mainly overcome by bone grafting through maxillary sinus floor elevation. Compared with traditional axial implantation, tilted implantation can better avoid bone grafting, reduce complications, shorten the treatment cycle, reduce the treatment cost for patients, and gradually be promoted in clinical settings. This article reviews the concept, biomechanics, clinical evaluation, and digital trend of tilted implants of maxillary posterior teeth.

Influence of different implant placement techniques to improve primary implant stability in low-density bone: A systematic review

Aim:

The aim of this study is to assess the influence of different implant placement techniques to improve primary implant stability (PIS) in the low-density bone.

Materials and Methods:

Citations published in English and those available in full text were searched from electronic databases (PubMed and Google Scholar) from the year 2000–2017 by which 75 manuscripts were revealed. After applying inclusion and exclusion criteria, seven were selected for the present review. The whole process was conducted by the following preferred reporting items for systematic reviews and meta-analyses guidelines.

Results:

The measurement of primary stability showed significant correlations with different bone densities and with implant outcome; however, these two parameters have not been investigated at the same time frequently. Of the seven manuscripts, three discussed standard drilling protocol, two used undersized drilling, one used guided drilling, and one compared standard drilling with undersized drilling. Several intraoperative methods of jaw bone-density assessment were reported, and resonance frequency analysis, periotest, and insertion torque values were used to quantify PIS.

Conclusion:

The use of undersized drilling has proven advantageous for increasing initial implant stability in the low-density bone. Although the PIS may be lower, the secondary implant stability is found to be correlated to acceptable values.

Clinical outcomes of partial and full-arch all-ceramic implant-supported fixed dental prostheses. A systematic review and meta-analysis

OBJECTIVE

To assess the survival and technical complication rate of partial and full-arch all-ceramic implant-supported fixed dental prostheses (P-FDP/FA-FDP) and supporting implants.

MATERIALS AND METHODS

An electronic search through three databases (MEDLINE/Pubmed, Cochrane Library, Embase) was conducted to identify relevant clinical studies with an observation period of at least 12 months, including ≥15 patients. Reconstruction and implant survival rates, technical complications and confounding variables such as processed/installed materials, retention mode and location in the mouth were obtained. Failure and complication rates were analyzed using standard Poisson regression models to calculate 5-year survival and complication estimates.

RESULTS

A total of five studies for the P-FDP group and seven studies for the FA-FDP group were included, throughout evaluating veneered zirconia reconstructions. In the P-FDP group, reconstructions were located in posterior regions. Meta-analysis indicated survival estimates on the reconstruction level of 98.3% and 97.7% for P- and FA-FDPs after 5 years. However, chipping of the veneering ceramic was frequent, resulting in estimated 5-year complication rates of 22.8% (P-FDPs) and 34.8% (FA-FDPs). Five-year survival estimates of implants supporting P-FDPs and FA-FDPs of 98.5% and 99.4% were calculated, respectively. Including a total of 540 FDPs, one screw-loosening and 11 de-cementations were reported. Confounding variables were not found to have a significant influence on survival and complication rates.

CONCLUSIONS

All-ceramic implant-supported P- and FA-FDPs comprising veneered zirconia frameworks showed high survival but clinically inacceptable fracture rates of the veneering ceramic. Their suitability with regard to this indication and a successful long-term outcome needs to be further evaluated.

Digital versus Traditional Workflow for Posterior Maxillary Rehabilitations Supported by One Straight and One Tilted Implant: A 3-Year Prospective Comparative Study

Objectives

The aim of the study was to evaluate and compare digital and traditional prosthetic workflow for posterior maxillary restorations supported by an upright and a distally tilted implant at 3-year follow-up.

Materials and Methods

Twenty-four patients were treated in the posterior maxilla with 24 immediately loaded axial and 24 distally tilted implants supporting 3-unit or 4-unit screw-retained prostheses. Three months after initial loading patients were randomly stratified into two groups: definitive traditional impressions were carried out in the control group, while digital impressions were performed in the test group. The framework-implant connection accuracy was evaluated by means intraoral digital radiographs at 3, 6, 12, and 36 months of follow-up examinations. Outcome considerations comprised implant and prosthetic survival and success rates, marginal bone level changes, and required clinical time to take impressions.

Results

A total of 24 patients received immediately loaded screw-retained prostheses supported by an upright and a distally tilted implant (total 48 implants). No implant dropouts occurred, showing an overall survival rate of 100% for both groups. None of the 24 fixed prostheses were lost during the observation period (prosthetic survival rate of 100%). No statistically significant differences in marginal bone loss were found between control and test groups. The digital impression procedure required on average less clinical time than the conventional procedure.

Conclusions

Clinical and radiologic results suggest that digital impression is a predictable procedure for posterior maxillary restorations supported by an upright and a distally tilted implant.

Biological and technical complications of tilted implants in comparison with straight implants supporting fixed dental prostheses. A systematic review and meta-analysis

OBJECTIVES

To evaluate the implant failure, marginal bone loss (MBL), and other biological or technical complications of restorations supported by tilted and straight implants after at least 3 years in function.

METHODS

Electronic and manual searches were performed in MEDLINE, Embase, Web of Science, and OpenGrey to identify clinical studies published up to December 2017. After duplicate study selection and data extraction, the risk of bias was assessed with the ROBINS-I tool. Random-effects meta-analyses of relative risks (RRs) or mean differences (MD) and their 95% confidence intervals (CIs) were performed, followed by subgroup/sensitivity analyses and application of the GRADE approach.

RESULTS

A total of 17 nonrandomized studies (eight prospective/nine retrospective) were included. The number of implants of the overall systematic review was 7,568 implants placed in 1,849 patients supporting either full-arch or partial implant prostheses. No difference in the failure of tilted and straight implants was seen (eight studies; 4,436 implants; RR = 0.95; 95% CI = 0.70 to 1.28; p = 0.74), with the quality of evidence being very low due to bias and imprecision. Likewise, no difference in MBL was seen between tilted and straight implants (16 studies; 5,293 implants; MD = 0.03 mm; 95% CI = -0.03 to 0.10 mm; p = 0.32), with the quality of evidence being very low due to bias and inconsistency. Contradictory results regarding implant survival were found from prospective and retrospective studies, which could indicate bias from the latter.

CONCLUSIONS

Within the limitations of the present systematic review, no effect of implant inclination on implant survival or peri-implant bone loss was found.

Influence of implant location on the clinical outcomes of implant abutments: a systematic review and meta-analysis

Purpose

To compare the failure events and incidence of complications of different abutment materials in anterior and posterior regions. Failure was defined as complete loss of the abutment requiring replacement by a new abutment.

Materials and methods

Electronic searches using PubMed/Medline and Google Scholar complemented with manual searches were performed with specific search terms. Searches were restricted to publications in English between January 2006 and March 2016.

Results

A total of 863 and 1,264 implants were inserted in the anterior and posterior regions, respectively, in a total of 1,529 patients. No titanium abutments failed in anterior or posterior regions. On the other hand, 1.6% of zirconia abutments failed in the anterior region and 1.5% failed in the posterior region. Technical complications occurred mostly in the posterior region and mostly involved zirconia abutment. Meta-analysis was possible only for zirconia-abutment failure, due to considerable heterogeneity of studies and outcome variables. No significant difference in failure rate was found between anterior and posterior zirconia abutments (risk ratio 1.53, 95% CI 0.49–4.77; P=0.47).

Conclusion

This systematic review and meta-analysis showed similar outcomes of different abutment materials when used in anterior and posterior regions in terms of failure events and biological and aesthetic complications. The only significant finding was the increased incidence of technical complications in the posterior region, mostly involving zirconia abutments. Abutment-screw loosening was the most common technical complication.

A systematic review and meta-analysis of 3-unit fixed dental prostheses: Are the results of 2 abutment implants comparable to the results of 2 abutment teeth?

The purpose of the systematic review and meta-analysis was to compare the performance of 3-unit bridges on teeth with 3-unit bridges on implants, evaluating survival of the bridges, survival of the teeth or implants, condition of the hard and soft tissues surrounding the supports, complications and patient-reported outcome measures (PROM) after a mean observation period of at least 1 year. A literature search was conducted using a combination of the search terms: fixed partial denture and fixed dental prostheses (FDPs). An electronic search for data published until January 2017 was undertaken using the MEDLINE, EMBASE and Cochrane Library databases. Eligibility criteria included clinical human studies, either randomised or not, interventional or observational, which evaluated the results of 3-unit FDPs on either 2 implants or 2 abutment teeth. The search identified 1686 unique references. After applying eligibility criteria, 66 articles were included in the analysis. A total of 1973 3-unit FDPs were supported by teeth, and 765 were implant-supported. No significant differences were found either in the survival of the supporting abutments (P = .52; 99% vs 98.7% survival per year) or in the survival of the prostheses (P = .34; 96.4% vs 97.4% survival per year). Both treatments show an almost equally low complication rate, but there is a low level of reporting of hard and soft tissue conditions and PROM. It is concluded that implant-supported 3-unit FDPs seem to be a reliable treatment with survival rates not significantly different from the results of teeth-supported 3-unit FDPs.

Definitive Abutments Placed at Implant Insertion and Never Removed: Is It an Effective Approach? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PURPOSE

To assess whether repeated abutment disconnections and reconnections have any impact on peri-implant bone resorption and soft tissue healing.

MATERIALS AND METHODS

Electronic and manual searches were conducted for English-language articles published up to March 2017 that identified a relation between repeated disconnections of implant abutments (PA group) and prosthetic or implant failures, complications, marginal bone loss (MBL), soft tissue healing, and esthetic evaluation (pink esthetic score [PES]) after at least 1 year of function compared with implants receiving a final abutment at the time of implant placement (DA group).

RESULTS

Fourteen articles (535 patients with 994 implants) were selected for qualitative analysis. Six of these were included in the meta-analysis. Five prostheses failed in the PA group and 1 failed in the DA group (P = .1047). Seven biologic complications occurred in the PA group and 6 occurred in the DA group (P = .8121). MBL was significantly less in the DA group (difference, 0.279 mm; P = .000). Greater buccal recession occurred in the PA group (difference, 0.198 mm; P = .0004). The PES evaluation showed no differences between groups (P = .289).

CONCLUSIONS

Repeated abutment disconnections and reconnections considerably increased MBL and buccal recession. Further studies are needed to confirm these results.

Dental Implants With Immediate Loading Using Insertion Torque of 30 Ncm: A Systematic Review

OBJECTIVE

This study aimed to perform a review of the literature regarding the survival rate of dental implants with immediate loading using insertion torque of 30 Ncm.

MATERIAL AND METHODS

A systematic review was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Cochrane Handbook for Systematic Reviews of Interventions (PROSPERO CRD42014015323). The search was performed in the PubMed, Web of Science, Cochrane Library electronic, OVID, and Scielo databases. Manual searches were also performed. The articles identified were assessed independently by 3 researchers. Clinical trials reporting dental implants with immediate loading and 30 Ncm torque in patients ages 18 years or older were included.

RESULTS

The searches yielded 589 studies. Six studies were included in the systematic review. The survival rate of dental implants was 96.8%. Three studies showed a low potential risk of bias.

CONCLUSION

There is not strong evidence that insertion torque of 30 Ncm is enough for implant survival in cases of immediate loading.

Sinus lift: 3 years follow up comparing autogenous bone block versus autogenous particulated grafts

Background/purpose

The aim of this prospective randomized controlled clinical trial was to compare vertical bone gain and bone resorption after sinus graft procedures performed either with particulate or with autogenous bone block.

Material and methods

Forty-one patients underwent sinus graft procedures with autogenous bone. They were randomly assigned to one group. The first group of 22 patients was treated with autogenous bone block with or without particulated bone, while in the second group of 19 patients sinus floor elevation was performed only with particulated autogenous bone. Linear measurements were recorded before surgery with a computed tomography scan at surgery and at 36 months after sinus lift grafting with a second computed tomography scan. To detect statistical differences Student t test was applied. Differences were considered significant if P values were < 0.05.

Results

There was a statistically significant difference in bone gain for the group treated with bone block grafts.

Conclusion

As a general clinical guideline the clinician should prefer, wherever feasible, en-block bone grafts for sinus floor augmentation procedures.

Retention Forces between Titanium and Zirconia Components of Two-Part Implant Abutments with Different Techniques of Surface Modification

BACKGROUND

The adhesive connection between titanium base and zirconia coping of two-part abutments may be responsible for the failure rate. A high mechanical stability between both components is essential for the long-term success.

PURPOSE

The aim of the present in-vitro study was to evaluate the influence of different surface modification techniques and resin-based luting agents on the retention forces between titanium and zirconia components in two-part implant abutments.

MATERIALS AND METHODS

A total of 120 abutments with a titanium base bonded to a zirconia coping were investigated. Two different resin-based luting agents (Panavia F 2.0 and RelyX Unicem) and six different surface modifications were used to fix these components, resulting in 12 test groups (n = 10). The surface of the test specimens was mechanically pretreated with aluminium oxide blasting in combination with application of two surface activating primers (Alloy Primer, Clearfil Ceramic Primer) or a tribological conditioning (Rocatec), respectively. All specimens underwent 10,000 thermal cycles between 5°C and 55°C in a moist environment. A pull-off test was then conducted to determine retention forces between the titanium and zirconia components, and statistical analysis was performed (two-way anova). Finally, fracture surfaces were analyzed by light and scanning electron microscopy.

RESULTS

No significant differences were found between Panavia F 2.0 and RelyX Unicem. However, the retention forces were significantly influenced by the surface modification technique used (p < 0.001). For both luting agents, the highest retention forces were found when adhesion surfaces of both the titanium bases and the zirconia copings were pretreated with aluminium oxide blasting, and with the application of Clearfil Ceramic Primer.

CONCLUSION

Surface modification techniques crucially influence the retention forces between titanium and zirconia components in two-part implant abutments. All adhesion surfaces should be pretreated by sandblasting. Moreover, a phosphate-based primer serves to enhance long-term retention of the components.

Why guided when freehand is easier, quicker, and less costly?

Computer-assisted implant planning and subsequent production of a surgical template based on this plan has gained attention because it provides restoratively driven esthetics, patient comfort, satisfaction, and the option of flapless surgery and immediate restoration. However, it adds expense and requires more time. Another significant but not so apparent advantage may be improved survival and success over freehand techniques in types III and IV bone. This retrospective analysis was undertaken to examine that possibility. It reports 1-year outcome for 80 implants in 27 consecutively presenting patients treated over a 7-year period using computer-assisted techniques across all bone qualities in commonly encountered treatment indications in private practice. Implants were placed to support single teeth, small bridges, and complete arch restorations in exposed or immediately restored applications, based on primary stability as determined by insertion torque, resonance frequency analysis, and Periotest. For the 80 implants supporting 35 restorations, the median observation period is 2.66 years; 73 implants supporting prostheses in 22 patients had readable radiographs at 1 year. There was a 1-year overall implant survival and a success rate of 100%. Radiographic analysis demonstrated the change in bone level from the platform at 1-year is less than 2 mm. Intra-operative median measurements of primary stability were insertion torque, 40 Ncm; resonance frequency, 76 ISQ; and Periotest, -3. All intra-operative measurements were consistent for acceptable primary stability regardless of bone density. Restoratively driven diagnosis and precision planning and initial fit were possible with computer-assisted techniques resulting in the achievement of high primary stability, even in areas of less dense bone. The ability to plan implant position, drill sequence, and implant design on the basis of predetermined bone density gives the practitioner enhanced pretreatment information which can lead to improved outcome.

Dynamic UCLA for single tilted implant in an aesthetic region

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This study investigated the aesthetic of the prosthesis rehabilitation.

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Patient satisfaction after rehabilitation.

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Importance of radiographic control case report.

Introduction

The aim of this paper was to present a rehabilitation of a patient with a dynamic universal castable long abutment (UCLA) for a single tilted implant in the anterior maxillary area.

Presentation of case

A 57-year-old male patient attended the dentistry college clinic complaining of a vertical fracture of a residual root of the dental element 22. The tooth extraction was indicated for the implant installation. Due to the socket buccal wall thickness, the implant was installed with an inclination to the palate. It was done in a two-stage surgical protocol, and an external hexagon implant (3.75 × 11.5 mm) was placed. After a six-month healing period to correct the implant position, a dynamic UCLA was set in place, rectifying the implant emergence profile at 20°. The ceramic structure fitting was performed and, after the patient’s consent, the prosthesis was finalized and installed.

Discussion

After a follow-up period of twenty months, no complications were observed.

Conclusion

The installation of tilted implants with a dynamic UCLA may be a viable option, faster and less invasive than bone grafts.

Prosthetic failure in implant dentistry

Although osseointegrated dental implants have become a predictable and effective modality for the treatment of single or multiple missing teeth, their use is associated with clinical complications. Such complications can be biologic, technical, mechanical, or esthetic and may compromise implant outcomes to various degrees. This article presents prosthetic complications accompanied with implant-supported single and partial fixed dental prostheses.

Tilted versus axially placed dental implants: a meta-analysis

OBJECTIVES

The purpose of the present review was to test the null hypothesis of no difference in the implant failure rate, marginal bone loss, and postoperative infection for patients being rehabilitated by tilted or by axially placed dental implants, against the alternative hypothesis of a difference.

METHODS

An electronic search without time or language restrictions was undertaken in July 2014. Eligibility criteria included clinical human studies, either randomised or not, interventional or observational. The estimates of an intervention were expressed in risk ratio (RR) and mean difference (MD) in millimetres.

RESULTS

The search strategy resulted in 44 publications. A total of 5029 dental implants were tilted (82 failures; 1.63%), and 5732 implants were axially placed (104 failures; 1.81%). The difference between the procedures did not significantly affect the implant failure rates (P=0.40), with a RR of 1.14 (95% CI 0.84-1.56). A statistically significant difference was found for implant failures when studies evaluating implants inserted in maxillae only were pooled (RR 1.70, 95% CI 1.05-2.74; P=0.03), the same not happening for the mandible (RR 0.77, 95% CI 0.39-1.52; P=0.45). There were no apparent significant effects of tilted dental implants on the occurrence of marginal bone loss (MD 0.03, 95% CI -0.03 to 0.08; P=0.32). Due to lack of satisfactory information, meta-analysis for the outcome 'postoperative infection' was not performed.

CONCLUSIONS

It is suggested that the differences in angulation of dental implants might not affect the implant survival or the marginal bone loss. The reliability and validity of the data collected and the potential for biases and confounding factors are some of the shortcomings of the present study.

CLINICAL SIGNIFICANCE

The question whether tilted implants are more at risk for failure than axially placed implants has received increasing attention in the last years. As the philosophies of treatment alter over time, a periodic review of the different concepts is necessary to refine techniques and eliminate unnecessary procedures. This would form a basis for optimum treatment.

Soft tissues stability of cad-cam and stock abutments in anterior regions: 2-year prospective multicentric cohort study

AIM

Aim of this study was to verify if the type of implant abutment manufacturing, stock or cad-cam, could influence the maintenance of stable gingival margins around single restorations in anterior areas.

METHODS

After 16 weeks of healing, implants (Osseospeed, Astra Tech Dental Implant) were positioned. Depending on the different fixture inclination and the thickness of buccal peri-implant soft tissue, abutment selection resulted in four groups: Group 1 (patients with zirconia ZirDesign(®) stock abutments), Group 2 (titanium stock TiDesign(®) abutments), Group 3 (zirconia cad-cam abutments), and Group 4 (titanium cad-cam abutments). The following parameters were assessed: buccal gingival margin modification (BGM). The modification of the implant gingival margin was followed at 1 and 2 years of follow-up. A computerized analysis was performed for measurements. Differences between soft tissue margin at baseline and after 2 years measured the gingival margin recession. A general linear model was used to evaluate each group in relation to gingival recession after two years. Tukey's post hoc test was used to compare the mean REC indexes of each group of abutments.

RESULTS

Seventy-two healthy patients (39 males and 33 females; mean age of 46 years) scheduled for single gap rehabilitation in anterior areas were enrolled. A 100% of implant survival rate was observed after 24 months of function. One failure occurred due to fracture of a Zirconia cad-cam abutment. Moreover, two abutment screw unscrewing were observed. Both for zirconia and titanium stock abutments (Group 1 and 2), the mean recession of implant buccal soft tissue was of 0.3 mm (SD of 0.3 and 0.4 mm, respectively). Soft tissue mean recession of zirconia and titanium cad-cam abutments (Group 3 and 4) was of 0.1 and -0.3 mm, respectively (SD of 0.3 and 0.4 mm, respectively). REC values of cad-cam titanium abutments (Group 4) were significantly lower than that of Group 1 (-0.57 mm), Group 2 (-0.61 mm), and Group 3 (-0.40 mm), respectively (Table 4).

CONCLUSION

In the anterior area, the use of cad-cam abutments is related to a better soft tissue stability. Such a relationship is significant if cad-cam titanium abutments are compared to both titanium and zirconia stock abutments.

Implant over implant: an alternative method for solving malpositioned osseointegrated implants at the sinus floor

An implant was malpositioned and osseointegrated at the maxillary sinus floor with no complications. However, unexpected bone formation over the implant made the implant nonfunctional. Because the patient rejected the removal of the implant, it was left in place while another short implant was placed into the newly formed bone in approximately the same position as the old implant to restore the posterior maxillary tooth. Within 6 months, the new implant over the old asymptomatic implant was functional. Radiographs revealed osseointegration and stable periimplant marginal bone level with no signs of infection or inflammation.

CAD/CAM glass ceramics for single-tooth implant crowns: a finite element analysis

PURPOSE

To evaluate the load distribution of CAD/CAM mono-ceramic crowns supported with single-tooth implants in functional area.

MATERIALS AND METHODS

A 3-dimensional numerical model of a soft tissue-level implant was constructed with cement-retained abutment to support glass ceramic machinable crown. Implant-abutment complex and the retained crown were embedded in a Ø 1.5 × 1.5 cm geometric matrix for evaluation of mechanical behavior of mono-ceramic CAD/CAM aluminosilicate and leucite glass crown materials. Laterally positioned axial load of 300 N was applied on the crowns. Resulting principal stresses in the mono-ceramic crowns were evaluated in relation to different glass ceramic materials.

RESULTS

The highest compressive stresses were observed at the cervical region of the buccal aspect of the crowns and were 89.98 and 89.99 MPa, for aluminosilicate and leucite glass ceramics, respectively. The highest tensile stresses were observed at the collar of the lingual part of the crowns and were 24.54 and 25.39 MPa, respectively.

CONCLUSION

Stresses induced upon 300 N static loading of CAD/CAM aluminosalicate and leucite glass ceramics are below the compressive strength of the materials. Impact loads may actuate the progress to end failure of mono-ceramic crowns supported by metallic implant abutments.

The effect of flapless surgery on implant survival and marginal bone level: a systematic review and meta-analysis

BACKGROUND

The clinical outcomes of implants placed using the flapless approach have not yet been systematically investigated. Hence, the present systematic review and meta-analysis aims to study the effect of the flapless technique on implant survival rates (SRs) and marginal bone levels (MBLs) compared with the conventional flap approach.

METHODS

An electronic search of five databases (from 1990 to March 2013), including PubMed, Ovid (MEDLINE), EMBASE, Web of Science, and Cochrane Central, and a hand search of peer-reviewed journals for relevant articles were performed. Human clinical trials with data on comparison of SR and changes in MBL between the flapless and conventional flap procedures, with at least five implants in each study group and a follow-up period of at least 6 months, were included.

RESULTS

Twelve studies, including seven randomized controlled trials (RCTs), one cohort study, one pilot study, and three retrospective case-controlled trials (CCTs), were included. The SR of each study was recorded, weighted mean difference (WMD) and confidence interval (CI) were calculated, and meta-analyses were performed for changes in MBL. The average SR is 97.0% (range, 90% to 100%) for the flapless procedure and 98.6% (range, 91.67% to 100%) for the flap procedure. Meta-analysis for the comparison of SR among selected studies presented a similar outcome (risk ratio = 0.99, 95% CI = 0.97 to 1.01, P = 0.30) for both interventions. Mean differences of MBL were retrieved from five RCTs and two retrospective CCTs and subsequently pooled into meta-analyses; however, none of the comparisons showed statistical significance. For RCTs, the WMD was 0.07, with a 95% CI of -0.05 to 0.20 (P = 0.26). For retrospective CCTs, the WMD was 0.23, with a 95% CI of -0.58 to 1.05 (P = 0.58). For the combined analysis, the WMD was 0.03, with a 95% CI of -0.11 to 0.18 (P = 0.67). The comparison of SR presented a low to moderate heterogeneity, but MBL presented a considerable heterogeneity among studies.

CONCLUSION

This systematic review revealed that the SRs and radiographic marginal bone loss of flapless intervention were comparable with the flap surgery approach.