Systematic review of the survival rate and the biological, technical, and aesthetic complications of fixed dental prostheses with cantilevers on implants reported in longitudinal studies with a mean of 5 years follow-up

Saving Single-rooted Teeth with Combined Endodontic-periodontal Lesions

INTRODUCTION

Teeth affected by combined endodontic-periodontal lesions are usually considered by all prognosis classifications as hopeless teeth. The development of new biomaterials combined with modern endodontic and periodontal regeneration techniques may improve dental prognosis and maintain the affected teeth. Moreover, 1 of the replacement options for those teeth, dental implants, has shown an increasing number of biological and technical complications.

METHODS

Five patients were included in this case series study. Full periodontal and radiographic examination revealed generalized chronic periodontitis. Moreover, endodontic-periodontal lesions affecting single-rooted teeth were detected in those patients with tissue destruction beyond the apex. After splinting those teeth, conventional endodontic and nonsurgical periodontal treatment was performed. Three months later, periodontal regeneration was applied at those teeth in order to reconstruct supporting tissues and to improve dental prognosis.

RESULTS

After a follow-up period ranging from 14 months to 17 years, it was observed that all teeth remain asymptomatic and in normal function. No signs of apical pathosis were observed, and the periodontium was stable. All patients were included in a strict maintenance program to check the periodontal and apical status.

CONCLUSIONS

This case series shows that it is possible to change the prognosis of teeth affected by combined endodontic-periodontal lesions, even if the periodontal support is destroyed beyond the apex.

Temperature rise during removal of fractured components out of the implant body: an in vitro study comparing two ultrasonic devices and five implant types

BACKGROUND

Ultrasonic instrumentation under magnification may facilitate mobilization of screw remnants but may induce heat trauma to surrounding bone. An increase of 5°C is considered detrimental to osseointegration. The objective of this investigation was to examine the rise in temperature of the outer implant body after 30 s of ultrasonic instrumentation to the inner part, in relation to implant type, type of ultrasonic equipment, and the use of coolants in vitro.

METHODS

Two ultrasonic devices (Satelec Suprasson T Max and Electro Medical Systems (EMS) miniMaster) were used on five different implant types that were provided with a thermo couple (Astra 3.5 mm, bone level Regular CrossFit (RC) 4.1 mm, bone level Narrow CrossFit (NC) 3.3 mm, Straumann tissue level regular body regular neck 3.3 mm, and Straumann tissue level wide body regular neck 4.8 mm), either with or without cooling during 30 s. Temperature rise at this point in time is the primary outcome measure. In addition, the mean maximum rise in temperature (all implants combined) was assessed and statistically compared among devices, implant systems, and cooling mode (independent t-tests, ANOVA, and post hoc analysis).

RESULTS

The Satelec device without cooling induces the highest temperature change of up to 13°C, particularly in both bone level implants (p < 0.05) but appears safe for approximately 10 s of continuous instrumentation, after which a cooling down period is rational. Cooling is effective for both devices. However, when the Satelec device is used with coolant for a longer period of time, a rise in temperature must be anticipated after cessation of instrumentation, and post-operational cooling is advised.

CONCLUSIONS

The in vitro setup used in this experiment implies that care should be taken when translating the observations to clinical recommendations, but it is carefully suggested that the EMS device causes limited rise in temperature, even without coolant.

No Clear Evidence of the Effect of Cantilevered Implant Supported Fixed Restorations on the Marginal Bone or the Prosthetic Complications

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Effect of cantilevers for implant-supported prostheses on marginal bone loss and prosthetic complications: systematic review and meta-analysis. Torrecillas-Martinez L, Monje A, Lin G, Suarez F, Ortega-Oller I, Galindo-Moreno P, Wang H. Int J Oral Maxillofac Implants 2014;29(6):1315-21.

SOURCE OF FUNDING

Not reported

STUDY DESIGN

Systematic review and meta-analysis.

Histological assessment of hard and soft tissues surrounding a novel ceramic implant: a pilot study in the minipig

OBJECTIVE

The aim of this study was to investigate clinical and soft/hard tissues histomorphological outcomes of a ceramic implant comparatively to a titanium implant in a minipig model.

MATERIAL AND METHODS

Eighteen soft tissue level implants (9 Ceramic with ZLA(®) surface as test, and 9 titanium SLActive(®) as control, Institut Straumann, Basel, Switzerland) were randomly placed into the mandible of 6 minipigs (n = 6). Two months later, animals were sacrificed and block biopsies were obtained to assess histomorphological outcomes. Unadjusted paired comparisons, of both groups were performed using the Wilcoxon signed rank test. The Dunnett-Hsu test was used to adjust for multiple comparisons.

RESULTS

All implants showed excellent integration into bone and soft tissue. The fBIC (distance implant shoulder to most coronal implant contact) and BIC% (percentage bone-to-implant contact) were for both groups; test: 3.95 mm and 85.4%; control 3.97 mm and 84.3% respectively. No difference in peri-implant mucosa height was found, however, the sulcular epithelium was significantly shorter for the ZrO2 (mean: 0.76, 95%CI: 0.46-1.06) than for the Ti (mean: 1.40, 95%CI: 1.10-1.70) (p = 0.0090).

CONCLUSIONS

Within the limits of this pilot study, no difference was found between the ceramic implant with ZLA(®) surface and a titanium implant in terms of bone tissue integration. Furthermore, the epithelial attachment favoured this ceramic implant over titanium.

Systemic Trans- and Postoperative Evaluations of Patients Undergoing Dental Implant Surgery

OBJECTIVE

The aims of this study were to examine the trans- and postoperative systemic characteristics of patients undergoing dental implant surgery and to investigate the relationship between pre- and post- surgery anxiety levels.

MATERIAL AND METHODS

Thirty-nine patients were analyzed in 3 call centers to determine anxiety levels, pain levels, and preoperative and postoperative histories using the State-Trait (STAI) questionnaire.

RESULTS

A total of 93 dental implants were installed, with a success rate of 100%. The most frequently reported systemic disease was hypertension. There was a significantly higher rate of effective clamping (torque) to the mandibular bone than to the maxillary bone. The association between postoperative surgical complications and longer operative time was not significant, but there was a significant correlation between the alteration of mouth opening and daily routine activities and a significant decrease in anxiety levels between the day of surgery and the postoperative time point (p =0.006).

CONCLUSION

A longer surgical time was associated with surgery-related complications and with a higher anxiety index on the preoperative evaluation.

New Ti-Alloys and Surface Modifications to Improve the Mechanical Properties and the Biological Response to Orthopedic and Dental Implants: A Review

Titanium implants are widely used in the orthopedic and dentistry fields for many decades, for joint arthroplasties, spinal and maxillofacial reconstructions, and dental prostheses. However, despite the quite satisfactory survival rates failures still exist. New Ti-alloys and surface treatments have been developed, in an attempt to overcome those failures. This review provides information about new Ti-alloys that provide better mechanical properties to the implants, such as superelasticity, mechanical strength, and corrosion resistance. Furthermore, in vitro and in vivo studies, which investigate the biocompatibility and cytotoxicity of these new biomaterials, are introduced. In addition, data regarding the bioactivity of new surface treatments and surface topographies on Ti-implants is provided. The aim of this paper is to discuss the current trends, advantages, and disadvantages of new titanium-based biomaterials, fabricated to enhance the quality of life of many patients around the world.

Managing a fractured implant: A clinical report

Implant fixture fracture is one of the reasons for late implant failure, with incidence rates ranging from 0.2% to 7.5%. Material defects, occlusal overload, prosthetic design, and nonpassive prosthesis fit have been identified as causative factors for implant fixture fractures. A custom-made prosthetic post was made to connect the remaining implant fixture and the implant-retained crown, as the fractured implant fixture exhibited no signs of infection and the fixture had adequate remaining length. In addition, complete removal of the implant could have resulted in significant bone loss at the site.

Long-Term (9–12 Years) Outcomes of Titanium Implants With an Oxidized Surface: A Retrospective Investigation on 209 Implants

The aim of this paper is to retrospectively assess the long-term clinical and radiological results in a group of patients treated with Brånemark TiUnite implants supporting mostly single-tooth and partial restorations. The clinical records of 90 consecutive patients (mean age 55.9 years; range 21–82 years), treated with 209 Brånemark System MkIII or MkIV TiUnite implants (72 maxillary/137 mandibular; 26 anterior intercanine/183 posterior sites), were analyzed. Indication types were single tooth (n = 21 implants), partial (n = 180) and full arches (n = 8). A delayed loading protocol was applied in 128 implants, while 81 were immediately loaded. Cumulative survival rate and marginal bone remodeling were evaluated. Marginal bone level was evaluated by an independent radiologist from periapical radiographs taken at implant insertion and at long-term follow up. Plaque, probing pocket depth and peri-implant mucosa conditions were also assessed. The results showed the mean follow-up duration was 11.0 years (range 9.6–12.4 years): 181 implants (90.5%) reached at least 10 years follow-up, 100 implants 11 years, and 17 implants 12 years. Overall, 6 implants failed in 4 patients (5 during the first year and 1 after 2 years) resulting in a 97.1% survival rate after 12 years. Mean bone levels at implant insertion and at the last follow up were −0.90 ± 1.16 mm (mean ± SD; n = 169) and −1.49 ± 0.95 mm (n = 195), respectively. Mean marginal bone remodeling from implant insertion to the last follow-up was −0.60 ± 1.17 mm (n = 168). At the last available follow-up, mean pocket depth was 1.65 ± 0.84 mm. Peri-implant mucosa was normal for the majority (97%) of implants. In conclusion, this retrospective long-term study showed excellent survival rate of TiUnite implants as well as favorable marginal bone response and soft tissue conditions.

Erythritol-Enriched Air-Polishing Powder for the Surgical Treatment of Peri-Implantitis

Peri-implantitis represents a major complication that can compromise the success and survival of implant-supported rehabilitations. Both surgical and nonsurgical treatment protocols were proposed to improve clinical parameters and to treat implants affected by peri-implantitis. A systematic review of the literature was performed on electronic databases. The use of air-polishing powder in surgical treatment of peri-implantitis was investigated. A total of five articles, of different study designs, were included in the review. A meta-analysis could not be performed. The data from included studies reported a substantial benefit of the use of air-polishing powders for the decontamination of implant surface in surgical protocols. A case report of guided bone regeneration in sites with implants affected by peri-implantitis was presented. Surgical treatment of peri-implantitis, though demanding and not supported by a wide scientific literature, could be considered a viable treatment option if an adequate decontamination of infected surfaces could be obtained.

High in vitro antibacterial activity of Pac-525 against Porphyromonas gingivalis biofilms cultured on titanium

In order to investigate the potential of short antimicrobial peptides (AMPs) as alternative antibacterial agents during the treatment of peri-implantitis, the cytotoxic activity of three short AMPs, that is, Pac-525, KSL-W, and KSL, was determined using the MTT assay. The antimicrobial activity of these AMPs, ranging in concentration from 0.0039 mg/mL to 0.5 mg/mL, against the predominant planktonic pathogens, including Streptococcus sanguis, Fusobacterium nucleatum, and Porphyromonas gingivalis, involved in peri-implantitis was investigated. Furthermore, 2-day-old P. gingivalis biofilms cultured on titanium surfaces were treated with Pac-525 and subsequently observed and analysed using confocal laser scanning microscopy (CLSM). The average cell proliferation curve indicated that there was no cytotoxicity due to the three short AMPs. The minimum inhibitory concentration and minimum bactericidal concentration values of Pac-525 were 0.0625 mg/mL and 0.125 mg/mL, respectively, for P. gingivalis and 0.0078 mg/mL and 0.0156 mg/mL, respectively, for F. nucleatum. Using CLSM, we confirmed that compared to 0.1% chlorhexidine, 0.5 mg/mL of Pac-525 caused a significant decrease in biofilm thickness and a decline in the percentage of live bacteria. These data indicate that Pac-525 has unique properties that might make it suitable for the inhibition the growth of pathogenic bacteria around dental implants.

Fixed restorations supported by Morse-taper connection implants: a retrospective clinical study with 10-20 years of follow-up

OBJECTIVES

Rehabilitation with implant-supported fixed prostheses is a predictable modality to restore lost function and esthetics; however, fixed restorations are subject to biological and prosthetic complications, which may represent a problem in the long-term. The aim of this study was to evaluate the long-term survival and complication rates of fixed restorations supported by Morse-taper connection implants.

MATERIALS AND METHODS

Between January 1992 and December 2002, 49 patients (age range 22-70 years), were included in this study. The restorations involved 58 fixed reconstructions (15 single crowns [SCS], 29 partial prostheses, 14 full-arches), supported by 178 Morse-taper connection implants with a follow-up ranging from 10 to 20 years. Outcomes such as implant survival, marginal bone loss, frequency of biological and prosthetic complications as well as "complication-free" survival of restorations were investigated.

RESULTS

The 20-year overall cumulative implant survival was 97.2%. A few biological (3.4%) and prosthetic (10.3%) complications were reported. The "complication-free" survival rate of restorations was 85.5%. No statistically significant differences were observed among patients' gender, age, smoking or parafunctional habits, prosthesis site and type.

CONCLUSIONS

Satisfactory "complication-free" survival rates can be achieved after 20 years for fixed restorations supported by Morse-taper connection implants, with minimal marginal bone loss and complications.

Survival and complication rates of fixed restorations supported by locking-taper implants: a prospective study with 1 to 10 years of follow-up

PURPOSE

The aim of this 10-year follow-up study was to evaluate the implant survival and complication rates of fixed restorations supported by locking-taper implants.

MATERIALS AND METHODS

Over a 10-year period (January 2002 to December 2011) all patients referred to a single private practice for treatment with fixed restorations (single crowns, SCs; fixed partial prostheses, FPPs; fixed full arches, FFAs) supported by dental implants were considered for inclusion in the study. At each annual follow-up session, clinical, radiographic, and prosthetic parameters were assessed. The surviving implant-supported restorations were defined as "complication free" in the absence of any biological or prosthetic (mechanical or technical) complication. The cumulative implant survival and the "complication-free" survival of fixed implant-supported restorations were identified using the Kaplan-Meier method. The Log-rank test was used to identify correlations between the study variables.

RESULTS

In total, 1494 locking-taper implants (727 maxilla, 767 mandible) were placed in 642 patients (356 males, 286 females). Nineteen implants (12 maxilla, 7 mandible) failed. Implant failures were attributed to lack of osseointegration (14 implants), peri-implantitis (4 implants), and mechanical overloading (1 implant). An overall 10-year cumulative implant survival rate of 98.7% (98.3% maxilla, 99.1% mandible) was found. The implant survival rates did not significantly differ with respect to implant location, position, bone type, implant length and diameter, and type of restorations. Among the surviving implant-supported restorations (478 SC, 242 FPP, 19 FFA), a few biological (11/739: 1.4%) and prosthetic (27/739: 3.6%) complications were reported. The incidence of mechanical complications was low (3/739: 0.4%), with three loosened abutments in three SCs (3/478: 0.6%), and no abutment fractures; technical complications were more frequent (24/739: 3.2%), with an incidence of decementation of 2.0% (SC 2.0%, FPP 1.6%, FFA 5.2%) and ceramic/veneer chipping/fracture of 1.2% (SC 0.0%, FPP 2.8%, FFA 10.5%). A 10-year cumulative "complication-free" survival of restorations of 88.6% (SC 91.7%, FPP 83.1%, FFA 73.8%) was reported. The complication rates differ significantly with respect to the type of restoration (p < 0.05).

CONCLUSIONS

Fixed restorations on locking-taper implants seem to be a successful procedure for the rehabilitation of partially and completely edentulous arches.

Dental implant fractures - aetiology, treatment and case report

PURPOSE

This study aimed to investigate the etiology, clinical manifestations, and treatment options of dental implants fractures through a literature review and to relate a clinical report.

METHODS

A literature review was performed using the Medline database and this paper describes a case demonstrating the management of implant fracture. Twenty two articles were selected in the present literature review.

RESULTS

Nowadays the use of dental implants to rehabilitate completely and partially edentulous patients became the best treatment option; however, this treatment is suitable to failure. The fracture of implant body is a possible complication. The fracture of implant body is a late complication and is related to the failure in implant design or material, non-passive fitting of the prosthetic crown and overloading. Clinically, prosthesis instability and spontaneous bleeding are observed. Three options of treatment have been indicated: complete removal of implant fragment, maintenance of implant fragment, and surface preparation of the fragment with insertion of a new abutment.

CONCLUSION

The literature indicates the complete removal of the fragment as the best treatment option.

Comparisons of maximum deformation and failure forces at the implant-abutment interface of titanium implants between titanium-alloy and zirconia abutments with two levels of marginal bone loss

Background

Zirconia materials are known for their optimal aesthetics, but they are brittle, and concerns remain about whether their mechanical properties are sufficient for withstanding the forces exerted in the oral cavity. Therefore, this study compared the maximum deformation and failure forces of titanium implants between titanium-alloy and zirconia abutments under oblique compressive forces in the presence of two levels of marginal bone loss.

Methods

Twenty implants were divided into Groups A and B, with simulated bone losses of 3.0 and 1.5 mm, respectively. Groups A and B were also each divided into two subgroups with five implants each: (1) titanium implants connected to titanium-alloy abutments and (2) titanium implants connected to zirconia abutments. The maximum deformation and failure forces of each sample was determined using a universal testing machine. The data were analyzed using the nonparametric Mann–Whitney test.

Results

The mean maximum deformation and failure forces obtained the subgroups were as follows: A1 (simulated bone loss of 3.0 mm, titanium-alloy abutment) = 540.6 N and 656.9 N, respectively; A2 (simulated bone loss of 3.0 mm, zirconia abutment) = 531.8 N and 852.7 N; B1 (simulated bone loss of 1.5 mm, titanium-alloy abutment) = 1070.9 N and 1260.2 N; and B2 (simulated bone loss of 1.5 mm, zirconia abutment) = 907.3 N and 1182.8 N. The maximum deformation force differed significantly between Groups B1 and B2 but not between Groups A1 and A2. The failure force did not differ between Groups A1 and A2 or between Groups B1 and B2. The maximum deformation and failure forces differed significantly between Groups A1 and B1 and between Groups A2 and B2.

Conclusions

Based on this experimental study, the maximum deformation and failure forces are lower for implants with a marginal bone loss of 3.0 mm than of 1.5 mm. Zirconia abutments can withstand physiological occlusal forces applied in the anterior region.