The single-tooth implant: a viable alternative for single-tooth replacement

Prefabricated shouldered abutments enable successful restoration of molar crowns on implants

PURPOSE

This retrospective study evaluated the effect of selected clinical and patient factors on survival, success, and peri-implant bone level changes of locking taper implants supporting molar crowns on Bicon's prefabricated shouldered abutments.

METHODS

A total of 234 patients, who received 274 single molar crowns supported by locking taper implants were included in this retrospective study. Kaplan-Meier survival analysis was used to assess overall implant survival, prostheses survival, and success. Crowns were either monolithic (resin based) or bilayered (milled fiber-reinforced composite coping veneered with indirect composite). Early and late changes in marginal bone levels were plotted and analyzed with equivalence testing to compare the effects of different factors on crestal bone levels.

RESULTS

At 9.5 years after implant surgery, the implant survival probability was 94.2%, the probability of prosthesis survival was 91.4%, and the probability of prosthetic success was 90.4%. Neither the use of different crown materials, nor the choice of monolithic versus bilayered crown construction, significantly affected the probability of prosthetic success. Marginal bone levels, on average, trended downwards towards the top of the implant within the first 2 years after functional loading, and remained stable on average, since then. Factors affecting bone levels included the use of nonsteroidal anti-inflammatory drugs, which precluded early implant bone loss; and subcrestal implant placement, which was linked to significantly higher long-term bone levels.

CONCLUSION

The implant and abutment system studied resulted in high implant and prosthetic survival rates, regardless of prosthetic material used, with stable bone levels over time.

Development of patient-specific finite element model for study of composite dental implants

Traumatic dental injuries can occur due to various reasons such as accidents, sports injuries, fights, falls, and others. These injuries can affect the teeth, gums, and surrounding tissues, and can range from minor chips and cracks to severe fractures, dislocations, and avulsions (when the tooth is completely knocked out of the socket). The most common way to address this is by replacing affected teeth with dental implants. The purpose of this research is to evaluate the use of composite materials in dental implants and compare them with the traditionally used materials using a patient specific cone beam computed tomography (CBCT) based finite element model (FEM). To conduct this research, two different implant groups i.e., traditional implant and composite implant were designed using Titanium grade 4, zirconium oxide-reinforced lithium silicate (ZLS), and Zirconia (ZrO2). Six dental implants were designed namely Ti implant, ZLS implant, ZrO2implant, Ti-ZrO2composite, Ti-ZLS composite, and ZLS-ZrO2composite using 3D modelling software. Detailed full-scale 3D models of patient specific dental implant were developed and traumatic loading conditions were applied to the enamel of central incisor teeth or crown of dental implant, and maxilla was constrained in all directions. It was found that the use of composite materials for dental implants can reduce the stresses over the surface of abutment and implant as compared to traditional implants. The detailed models developed as a part of this study can advance the research on dental implants, and with further experimental validation allow the use of composite materials for fabrication of more stable dental implants.

Replacement of Congenitally Missing Maxillary Lateral Incisor with Two-Buccal-Retainer Resin-Bonded Fixed Dental Prosthesis Modified by Proximal Boxes

A 21-year-old male patient with congenitally missing maxillary right lateral incisor presented to Fixed Prosthodontics Department at the Faculty of Dentistry, Damascus University (Damascus, Syria). A two-buccal-retainer lithium disilicate glass-ceramic resin-bonded fixed dental prosthesis (RBFDP) was chosen to replace the missing tooth. This clinical report describes a novel preparation design of two-buccal-retainer lithium disilicate glass-ceramic RBFDP modified by proximal boxes. A recall appointment after 3 years showed no fracture, no de-bonding, no secondary caries, and no staining in prosthesis margins. Color matching with natural teeth was excellent, and the patient was satisfied.

Inhibition of neutrophil inflammatory mediator expression by azithromycin

BACKGROUND AND OBJECTIVE

Peri-implant tissues appear to exhibit a more vigorous inflammatory response during post-operative healing than periodontal tissues. There is evidence that a single dose of amoxicillin (AMX) prior to implant surgery reduces the risk of early peri-implant healing complications. This study compared the effects of AZM and AMX on neutrophil expression of mRNA for mediators involved in peri-implant healing.

MATERIALS AND METHODS

Neutrophils were isolated from healthy human donors and pre-incubated with AZM (4 or 8 μg/ml) or AMX (2 or 4 μg/ml). Cells were then incubated with LPS (1 μg/ml), TNF-α (10 ng/ml), or medium alone (control) for 1, 2, and 4 h. Total RNA was analyzed with qPCR to quantify changes in expression of the six inflammatory mediators.

RESULTS

LPS and TNF-α induced a similar pattern of IL-1β mRNA expression, with peak expression at 1 h. For most mediators, gene expression in neutrophils activated by LPS was markedly reduced in a dose-dependent manner by AZM. Therapeutic concentrations of AZM (8 μg/ml) consistently reduced expression of mediators tested in this study. AMX was effective only in a few cases and under certain conditions. Therefore, AZM was more effective in its direct anti-inflammatory action.

CONCLUSION

AZM is a consistent and effective inhibitor of neutrophil inflammatory mediator mRNA expression.

CLINICAL RELEVANCE

Given that a single dose of AZM produces higher and more sustained concentrations of this agent in periodontal tissues than AMX when used as a pre-operative prophylactic antibiotic, AZM has greater potential to inhibit inflammatory mediator expression at peri-implant wound sites than AMX.

Considerations in the replacement of over-retained primary teeth with implant restorations in the esthetic zone: A case report

OBJECTIVE

There exist several treatment planning and clinical challenges when treating over-retained primary teeth with dental implants-especially in the esthetic zone where the existing hard and soft tissue positions are not in harmony with adjacent dentition and do not serve as reliable landmarks for implant placement and restoration. In this report, we highlight some of the key aspects for achieving predictable treatment outcomes for implant restorations replacing over-retained primary teeth in the esthetic zone.

CLINICAL CONSIDERATIONS

This clinical report describes the treatment of a patient who presented with over-retained deciduous canines consequent to congenitally missing maxillary lateral incisors. The deciduous canines were deemed hopeless, and subsequently replaced with immediately placed implants following a computer-guided protocol. The optimal implant positions were determined through a diagnostic wax-up correcting the existing gingival discrepancies with the adjacent teeth. Existing periapical infections were addressed utilizing a vestibular approach to minimize the postoperative recession and scarring and achieve a more predictable esthetic outcome. Final restorations were fabricated with all ceramic materials for optimal esthetics.

CONCLUSION

When planning for implants to replace over-retained primary teeth, it is essential to visualize the desired contours of the final restorations and correct the level of the existing gingival discrepancies by planning the proper implant position and angulation in relation to the adjacent teeth and gingival positions.

CLINICAL SIGNIFICANCE

Careful treatment planning coupled with a guided implant workflow allows for a successful surgical and esthetic outcome for the replacement of over-retained primary teeth with implant restorations.

The effectiveness of immediate implant placement for single tooth replacement compared to delayed implant placement: A systematic review and meta-analysis

AIM

To compare immediate implant placement (IIP) to delayed single implant placement (DIP, ≥3 months post-extraction) in terms of implant survival (primary outcome), surgical, clinical, aesthetic, radiographic and patient-reported outcomes (secondary outcomes).

MATERIALS AND METHODS

Two reviewers independently performed an electronic search in PubMed, Web of Science, EMBASE and Cochrane and a hand search to identify eligible studies up to May 2018. Only randomized controlled trials (RCTs) and non-randomized controlled studies (NRSs) comparing IIP to DIP with at least 1 year of follow-up were selected for a qualitative analysis and meta-analysis.

RESULTS

The search identified 3 RCTs and 5 NRSs out of 2,589 titles providing data on 473 single implants (IIP: 233, DIP: 240) that had been in function between 12 and 96 months. One RCT showed unclear risk of bias, whereas all other studies demonstrated high risk. Meta-analysis showed significantly lower implant survival for IIP (94.9%) as compared to DIP (98.9%) (RR 0.96, 95% CI [0.93; 0.99], p = 0.02). All were early implant failures. A subgroup meta-analysis demonstrated a trend towards lower implant survival for IIP when postoperative antibiotics had not been administered (RR: 0.93, 95% CI [0.86; 1.00], p = 0.07). This was not observed among studies including the administration of postoperative antibiotics (RR: 0.98, 95% CI [0.94; 1.02], p = 0.35). Meta-analyses showed similar probing depth (WMD 0.43 mm, 95% CI [-0.47; 1.33], p = 0.35) and aesthetic outcomes as assessed by the pink aesthetic score (standardized WMD -0.03, 95% CI [-0.46; 0.39], p = 0.88) for IIP and DIP. Data on marginal bone loss were conflicting and highly biased. Soft tissue recession was underreported and available data were highly biased. Patient-reported outcomes were underreported, yet both IIP and DIP seemed well tolerated.

CONCLUSION

Immediate implant placement demonstrated higher risk for early implant loss than DIP. There is a need for RCTs comparing IIP to DIP with CBCT analyses at different time points and data on midfacial recession with the preoperative status as baseline. In these studies, the need for hard and soft tissue grafting should also be evaluated.

A comparison of implant complications and failures between the maxilla and the mandible

STATEMENT OF PROBLEM

Identifying factors that affect the clinical outcomes of implant therapy is important.

PURPOSE

The purpose of this retrospective study was to determine whether implant location was a factor affecting the complication and failure rates of single-tooth implant-supported restorations in a predoctoral setting.

MATERIAL AND METHODS

The charts of 431 patients treated with a surgically placed dental implant and restored with a single crown in the predoctoral clinic were analyzed. Data on implant location, type of complication (surgical or prosthetic), and type of failure were collected and analyzed according to implant location using the Fisher Exact Test and Mantel-Haenszel Exact Chi Square Test analysis (α=.05).

RESULTS

The charts revealed 158 complications (68 surgical and 90 prosthetic) in 110 patients, and 3.9% of the implants failed. No statistically significant difference was found between the number of surgical complications or prosthetic complications in the maxilla and the mandible (P=.469).

CONCLUSIONS

Jaw location (maxilla compared with mandible) of the implant had no statistically significant impact on the incidence of surgically or prosthetically related complications. No statistically significant difference was found in overall implant failures, surgical failures, and prosthetic failures between maxillary and mandibular implants.

Implant placement and loading protocols in partially edentulous patients: A systematic review

OBJECTIVES

To systematically review the evidence for the clinical outcome of fixed implant prostheses treated with different combinations of implant placement and loading protocols in partially edentulous patients.

MATERIALS AND METHODS

An electronic search was performed in Medline, Embase, and Central to identify studies investigating the outcome of implants subjected to immediate placement + immediate restoration/loading (Type 1A), immediate placement + early loading (Type 1B), immediate placement + conventional loading (Type 1C), early placement + immediate restoration/loading (Type 2-3A), early placement + early loading (Type 2-3B), early placement + conventional loading (Type 2-3C), late placement + immediate restoration/loading (Type 4A), late placement + early loading (Type 4B), late placement + conventional loading (Type 4C) with implant-supported fixed dental prostheses (IFDPs) in partially edentulous patients. Only human studies with at least 10 cases and a minimum follow-up time of 12 months, reporting on solid-screw-type implants with rough surfaces and an intra-osseous diameter between 3 and 6 mm, were included. A cumulative survival rate for each type of the implant placement and loading protocols was weighted by the duration of follow-up and number of implants.

RESULTS

The search provided 5,248 titles from which 2,362 abstracts and 449 full-text articles were screened. A total of 69 publications that comprised 23 comparative studies (15 randomized controlled trials, 7 controlled clinical trials) and 47 noncomparative studies (34 prospective cohort studies, 13 retrospective cohort studies) were included for analysis. Considerable heterogeneity in study design was found, and therefore, a meta-analysis of controlled studies was not possible. The weighted cumulative survival rate of each type of placement and loading protocol was 98.4% (Type 1A), 98.2% (Type 1B), 96.0% (Type 1C), 100% (Type 2-3B), 96.3% (Type 2-3C), 97.9% (Type 4A), 98.3% (Type 4B), and 97.7% (Type 4C). Type 1C, Type 2-3C, Type 4B, and Type 4C were scientifically and clinically validated (SCV). Type 1A, Type 1B, and Type 4A were clinically documented (CD), and Type 2-3A and Type 2-3B were clinically insufficiently documented (CID).

CONCLUSIONS

Evaluating outcomes in oral implantology by combining the placement and loading protocols are paramount. The selected loading protocol appears to influence the outcome of immediate implant placement.

An Alternative Approach for Space Opening in a Bilateral Maxillary Lateral Incisor Agenesis Patient using Miniplates

AIM

This case report aimed to present an orthodontic mechanic alternative for space opening in a patient missing maxillary lateral incisors, using miniplates as anchorage, associated with self-ligating brackets.

BACKGROUND

Dental agenesis affects the population causing esthetic and functional damages. The prevalence of missing maxillary lateral incisors should be considered for its significant rate and negative impact on smile esthetics.

CASE REPORT

This treatment was chosen based on the presence of balanced facial pattern, large canine anatomy, the need to improve dental occlusion to prevent further wear, and patient's esthetic complaint. To obtain the results, upper third molars were extracted, and two miniplates were installed to distalize the upper arch with no need for patient compliance or auxiliary devices. Self-ligating brackets were used to reduce friction on posterior teeth, thus facilitating movement with light force application. At the end of 19 months, the patient presented with class I good overbite and overjet, and adequate space for implant and prosthetics; also, good facial esthetic was maintained.

CONCLUSION

When indicated, space opening may provide excellent esthetics and functional results, and even more predictable results when skeletal anchorage miniplates are used to distalize all posterior teeth.

CLINICAL SIGNIFICANCE

Considering the high level of esthetic and functional compromise caused by dental agenesis, the technique hereby described represents a viable mechanic alternative within orthodontic possibilities.

The Management of the Dilacerated Impacted Maxillary Central Incisor

The clinical problem of how best to manage a dilacerated, impacted maxillary central incisor will only be encountered rarely. The treatment aim should be to achieve results that are indistinguishable from normal appearance in a way that is appropriate for the patient. This article discusses the incidence of dilacerations in maxillary incisors and describes the treatment approaches available − orthodontic alignment or surgical removal and management of the resulting space, considering orthodontic repositioning, autotransplantation and various prosthetic replacements. Treatment indications, advantages and disadvantages, restorative and surgical implications, as well as the evidence-base relating to the various treatment modalities will be presented, along with clinical case examples. Clinical relevance: This paper discusses a problem that, if not managed appropriately, can lead to poor results for the patient. Even for practitioners who may not undertake the treatment mentioned, it will enable them to have more in-depth discussion with their patients should the situation arise.

Restoring Congenitally Missing Maxillary Lateral Incisors Using Zirconia-Based Resin Bonded Prostheses

OBJECTIVE

This clinical report describes an alternative treatment modality for the replacement of congenitally missing maxillary lateral incisors in a 17-year-old patient.

CLINICAL CONSIDERATIONS

Zirconia-based resin-bonded fixed partial dentures (RBFPDs) were selected as a viable and conservative treatment option in a young individual with highly aesthetic expectations. Fabrication of all-ceramic RBFPDs followed specific preparation design and features to accommodate two retainers. The zirconia frameworks with bilateral wings were digitally designed and then milled by a computer-aided design and computer-aided manufacturing (CAD/CAM)-controlled milling machine. Zirconia surface was treated with a two-step chairside tribochemical silica-coating/silane coupling surface treatment protocol, and adhesive resin luting cement was used to achieve micromechanical and chemical bonding. Completion of the treatment resulted in a functional and aesthetic successful outcome and a 17-month follow-up presented uneventful.

CONCLUSION

Contemporary adhesive techniques involving resin-bonded zirconia-based prostheses can be utilized successfully and predictably in young patients with single missing teeth when implant therapy is currently not a treatment of choice and a less invasive approach is desired.

CLINICAL SIGNIFICANCE

The zirconia-based resin-bonded prosthesis constitutes a viable and conservative treatment modality for the replacement of missing teeth either congenitally or from another etiology in young patients in which implant therapy and a fixed partial denture are currently contraindicated.

Clinical evaluation of submerged and non-submerged implants for posterior single-tooth replacements: a randomized split-mouth clinical trial

The aim of this study was to evaluate clinical and radiographic results of submerged and non-submerged implants for posterior single-tooth replacements and to assess patient-based outcomes. Twenty patients were included in the study. A split-mouth design was used; implants inserted using a submerged technique were compared to those inserted with a non-submerged technique. Implants were restored with metal-ceramic crowns after 3 months. Reconstructions were examined at baseline, 6, 12, and 24 months. Standardized radiographs were made. Radiographic crestal bone level changes were calculated, as well as soft tissue parameters, including pocket probing depth, bleeding on probing, plaque index, and gingival index. Results were analyzed by two-way repeated measures of variance (ANOVA). To evaluate patient-based outcomes, patients were asked to complete a questionnaire at the 6-month follow-up; the Wilcoxon paired signed rank test was used to compare scores. The data of 18 patients were reviewed. During 24 months, non-submerged implants (0.57 ± 0.21 mm) showed significantly lower bone loss than submerged implants (0.68 ± 0.22 mm) (P<0.01). Patient satisfaction with non-submerged implants (median 87.5) was significantly higher than with submerged implants (median 81.5) (P<0.01). Non-submerged implants showed comparable clinical results to submerged implants and resulted in higher patient satisfaction due to decreased surgical intervention.

Replacement of missing lateral incisors with lithium disilicate glass-ceramic veneer-fixed dental prostheses: a clinical report

Key Clinical Message

This report describes the use of lithium disilicate glass-ceramic veneer-fixed dental prostheses in replacing congenitally missing maxillary lateral incisors. This kind of prosthesis has an advantage over a lingual-retainer resin-bonded fixed dental prosthesis in its capability of changing the color and shape of the abutment teeth. The prostheses provided an acceptable esthetics and comfort for the patient.

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.

Aesthetic Analysis of an Implant-Supported Denture at the Cleft Area

Objective

To evaluate the aesthetics of an implant-supported denture at the cleft area, comparing the peri-implant tissues and prosthetic crown with the contralateral tooth.

Settings

Hospital for Rehabilitation of Craniofacial Anomalies, Bauru, São Paolo, Brazil.

Patients

A total of 39 individuals of both genders, with complete unilateral cleft lip and palate, who received secondary alveolar bone graft and were rehabilitated with single implant-supported dentures at the area of the missing maxillary lateral incisor after completion of orthodontic treatment.

Interventions

The following parameters were analyzed in follow-up sessions: length and width of prosthetic crown and contralateral tooth, characteristics of implants, filling of interproximal space by the papilla, and smile height of the patients.

Results

The implant-supported prosthetic crowns were longer than the contralateral tooth ( p < .001). Among the 78 papillae analyzed, 29 (37.17%) received a score of 3; 32 (41.02%) papillae had a score of 2; and 17 (21.79%) received a score of 1. Concerning the smile height, among the 39 patients analyzed, 23 (56.41%) had a medium smile, 15 (38.46%) had a high smile, and two (5.12%) presented a low smile.

Conclusion

The use of dental implants to rehabilitate the edentulous cleft area is an excellent option. However, adequate evaluation of the bone quantity and quality, positioning and shape of adjacent teeth, smile height, and patient expectations should be considered to achieve success and avoid aesthetic deformities such as elongated teeth and absence of gingival papillae.

Multidisciplinary approach for the aesthetic treatment of maxillary lateral incisors agenesis: thinking about implants?

Missing maxillary lateral incisors create an esthetic problem with specific orthodontic and prosthetic considerations. Implants are commonly used to replace congenitally missing lateral incisors in adolescent orthodontic patients. However, an interdisciplinary approach should be observed during the diagnosis, prognosis, and treatment plan to provide a result with good predictability and meet the esthetic and functional expectations of the patient. The present study describes a case of a young patient with tooth agenesis of maxillary lateral incisors, which was conducted with an integrated planning. After 5-year follow-up of 2 fixed implant-supported prostheses, clinical and radiographic examination showed the treatment to be successful.

Masticatory function following implants replacing a second molar

Purpose

The aim of this study was to obtain objective and standardized information on masticatory function and patient satisfaction following second molar single implant therapy.

Methods

Twenty adult patients, who had restored second molar single implants more than 1 month before the study, were enrolled in this study. All patients received a chewing test using peanuts before and after insertion of the implant prosthesis, with a questionnaire and visual analogue scale (VAS) to evaluate the effect of second molar single implant therapy.

Results

This study obtained standardized information on the masticatory function objectively (e.g., P, R, X₅₀) before (Pre-insertion) and after insertion (Post-insertion) of the implant prosthesis. Masticatory performance (P) after insertion of the implant prosthesis significantly increased from 67.8±9.9 to 84.3±8.5% (P<0.0001). With the implant prosthesis, the P value increased by 24%. The masticatory efficiency index (R) of Post-insertion is higher than that of Pre-insertion (P<0.0001). With the implant prosthesis, the R value increased by 29%. The median particle size (X₅₀) of Post-insertion is lower than that of Pre-insertion (P<0.0001). More than 90% of the patients were satisfied with the second molar single implant therapy from a functional point of view.

Conclusions

These findings indicate that a second molar single implant can increase masticatory function.

Implant restoration of partially edentulous ridges: a review of 121 Nigerian patients

OBJECTIVE

Because of increasing health awareness, many Nigerian patients are demanding that their lost tooth/teeth be replaced with dental implants. This study reports the pattern and distribution of implant replacement of lost tooth/teeth in a private dental practice in Lagos, Nigeria.

METHODS

A retrospective review of implant replacement of lost tooth/teeth over a period of 6 years at Schubbs Private Dental Clinic, Lagos, was carried out. Data analysis included age, sex, occupation, habits and medical condition of patients, augmentation procedure, technique of implant placement (immediate vs conventional loading) tooth/teeth replaced, and follow-up period.

RESULTS

A total of 227 implants (Bicon, Boston, MA) with complete superstructure were placed in 121 patients(males = 68, females = 53; age range: 15-74 years). Majority of the patients were of high socioeconomic class. Ten (8.3%) patients had immediate implants and 111 (91.7%) undergone 2-stage implant procedures. The highest number (39.2%) of implants was placed in the molar region, and the replacement of the canines was the lowest (3.1%). Success rate over a period of 6 years was 96%. Of the 9 (4%) implants that failed, 2 were repeated and remained functional till date.

CONCLUSIONS

Dental implant therapy as a means of tooth replacement is gaining popularity among Nigerian social upper class. Success rate in this series is comparable with previous reports from Europe and America.

Implant supported prosthesis in a patient with progeria: case report

Prosthodontic rehabilitation can be accomplished with fixed, overdenture, complete, or implant-retained prostheses. Dental treatment overcomes the patient's functional, psychological, esthetic and phonation problems. Remaining healthy teeth may allow the dentist to fabricate a removable partial overdenture, fixed partial prosthesis or implant - supported prosthesis. The retention of a number of abutments helps maintain a positive ridge form with greater height and volume of the alveolar bone, improving masticatory performance, as well as providing a more stable prostheses. Dental patients who have medical problems need many treatment procedures. Multidisciplinary treatment planning is invaluable for patient's dental health. Progeria is a rare genetic condition where symptoms resembling aspects of aging are manifested at an early age. characteristic clinical findings of Progeria disease include abnormalities of the skin and hair in conjunction with characteristic facial features and skeletal abnormalities. The characteristic facies show protruding ears, beaked nose, thin lips with centrofacial cyanosis, prominent eyes, frontal and parietal bossing with pseudohydrocephaly, midface hypoplasia with micrognathia and large anterior fontanel. The other reported anomalies are dystrophic nails, hypertrophic scars and hypoplastic nipples. The findings that are nearly interested in dentistry are delayed dentition, anodontia, hypodontia, or crowding of teeth. This article presents the multidisciplinary dental treatment planning includes surgical, endodontic and prosthetic treatment of a patient with a history of progeria. In this case complete-arch fixed prostheses in both maxilla and mandible, supported by a combination of implants and teeth are reported.

Dealing with dental implant failures

An implant-supported restoration offers a predictable treatment for tooth replacement. Reported success rates for dental implants are high. Nevertheless, failures that mandate immediate implant removal do occur. The consequences of implant removal jeopardize the clinician's efforts to accomplish satisfactory function and esthetics. For the patient, this usually involves further cost and additional procedures. The aim of this paper is to describe different methods and treatment modalities to deal with dental implant failure. The main topics for discussion include identifying the failing implant, implants replacing failed implants at the exact site, and the use of other restorative options.When an implant fails, a tailor made treatment plan should be provided to each patient according to all relevant variables. Patients should be informed regarding all possible treatment modalities following implant failure and give their consent to the most appropriate treatment option for them.

Success and Survival of Single Dental Implants Placed in Sites of Previously Failed Implants

BACKGROUND

The aim of this study was to assess the clinical effectiveness of single dental implants placed in sites of previously failed implants.

METHODS

The study consisted of a consecutive cohort of 1,215 patients who received 1,387 single implants for single-tooth replacement during a 6-year period (1999 to 2005). Inclusion criteria were a single implant replacing a previously failed implant and follow-up data > or =6 months. Data were recorded and analyzed regarding implant survival and location, need for bone augmentation, and implant dimensions.

RESULTS

A total of 75 patients experienced the failure of 96 implants. Of those, 31 implants in 28 patients were replaced by a similar implant placed in the same location. Nine of the replacement implants failed, resulting in an overall survival rate of 71%. Follow-up ranged from 6 to 46 months (mean, 19.4 +/- 11.4 months). Replacement of maxillary and mandibular failed implants was similar. All failures occurred during the first year after implant replacement. On average, implant replacement occurred 5.8 +/- 5.2 months after original implant removal; three implants were placed immediately after implant removal. A third attempt for single implant replacement was made in two patients. However, one failed.

CONCLUSIONS

Replacement of a failed implant presents a challenge to achieve osseointegration in a healed bone site and may result in a decline in the survival rates. Patients and clinicians should be aware of these results before a replacement attempt is considered. The success of replacement may be increased by the use of wider implants or with improved surfaces.

Triple Immediate Therapy (ridge expansion, soft tissue augmentation, and provisional restoration) of Maxillary Anterior Single Implant

BACKGROUND

Immediate restoration during implant placement in the premaxillary area can achieve a favorable esthetic result. However, the treatment always poses a great challenge to clinicians, especially for patients with preexisting soft and hard tissue deficiencies. The aim of this clinical report was to present a protocol for a multidisciplinary approach to provide an immediate implant restoration for patients with ridge deficiency.

METHODS

A 21-year-old female presented with a mesial shift of the maxillary right canine due to loss of a lateral incisor at an early age. The treatment protocol included orthodontic space redistribution to open a canine space for implant placement. Subsequently, ridge expansion and implant placement combined with connective tissue grafting for the reconstruction of the soft tissue profile were performed, and an immediate provisional prosthesis was delivered simultaneously. A definitive University of California at Los Angeles-style ceramometal crown was completed 6 months later with periodical clinical maintenance.

RESULTS

The 18-month postoperative follow-up revealed that the implant was stable, and the buccal depression of the surgical area was reconstructed. Papillae were augmented, and a harmonious soft tissue margin was achieved in the esthetic zone. Radiographs demonstrated a normal vertical osseous height and excellent osseointegration of the implant.

CONCLUSIONS

The combination technique of ridge expansion and soft tissue augmentation can be applied to immediate implant restoration cases without the need for complicated bone grafting surgeries in atrophic ridges. This triple immediate strategy enabled us to reduce the number of surgeries, which simplified the overall procedure without compromising the esthetic results.

Tactile sensibility of single-tooth implants and natural teeth

AIM

The purpose of this randomized split-mouth clinical trial was to determine the active tactile sensibility between single-tooth implants and opposing natural teeth and to compare it with the tactile sensibility of pairs of natural teeth on the contralateral side in the same mouth (intraindividual comparison).

MATERIAL AND METHODS

The hypothesis was that the active tactile sensibilities of the implant side and control side are equivalent. Sixty two subjects (n=36 from Bonn, n=26 from Bern) with single-tooth implants (22 anterior and 40 posterior dental implants) were asked to bite on narrow copper foil strips varying in thickness (5-200 microm) and to decide whether or not they were able to identify a foreign body between their teeth. Active tactile sensibility was defined as the 50% threshold of correct answers estimated by means of the Weibull distribution.

RESULTS

The results obtained for the interocclusal perception sensibility differed between subjects far more than they differed between natural teeth and implants in the same individual [implant/natural tooth: 16.7+/-11.3 microm (0.6-53.1 microm); natural tooth/natural tooth: 14.3+/-10.6 microm (0.5-68.2 microm)]. The intraindividual differences only amounted to a mean value of 2.4+/-9.4 microm (-15.1 to 27.5 microm). The result of our statistical calculations showed that the active tactile sensibility of single-tooth implants, both in the anterior and posterior region of the mouth, in combination with a natural opposing tooth is similar to that of pairs of opposing natural teeth (double t-test, equivalence margin: +/-8 microm, P<0.001, power >80%). Hence, the implants could be integrated in the stomatognathic control circuit.

A Retrospective Evaluation of 1,387 Single-Tooth Implants: A 6-Year Follow-Up

BACKGROUND

The aim of this study was to evaluate the overall survival rate and factors that affect the clinical outcome of 1,387 consecutively placed implant-supported single restorations up to 6 years.

METHODS

During 6 years (1999 to 2005), 1,387 implants were placed in 1,215 subjects (1,073 males and 142 females) who required single-tooth replacements. The average time from implant placement was 2.7 +/- 3.27 years. Implants were mostly placed in the maxillary premolar area (39.5%) followed by the anterior maxillary area (28.7%). Implant survival and location, need for bone augmentation, and implant dimensions were recorded and analyzed.

RESULTS

Failed implants totaled 96, resulting in an overall survival rate of 93.1%. The vast majority of failures (94.8%) occurred during the first year following implant placement. Bone augmentation was performed in 9.7% of the implants with a 92.5% survival rate, similar to the survival rate of non-augmented areas (93.1%; P = 0.79). The average implant length was 13.3 mm, ranging from 8 to 16 mm. Longer implants (> or =11 mm) showed similar survival rates as implants <11 mm (93.2% versus 90.2%, respectively; P = 0.4). Implant width ranged between 3.25 to 5 mm (mean 3.9), with no effect on implant survival (P = 0.43). There was a significant difference in implant survival according to the anatomic zone of implant placement (P = 0.0075). The maxillary premolar area showed the highest survival rate (96.2%).

CONCLUSION

Implant-supported single-tooth replacement is a predictable procedure with good survival rates up to 6 years.

Managing congenitally missing lateral incisors. Part III: single-tooth implants

Three treatment options exist for the replacement of congenitally missing lateral incisors. They include canine substitution, a tooth-supported restoration, and a single-tooth implant. Selecting the appropriate treatment option depends on the malocclusion, anterior relationship, specific space requirements, and condition of the adjacent teeth. The ideal treatment is the most conservative option that satisfies individual esthetic and functional requirements. Today, the single-tooth implant has become one of the most common treatment alternatives for the replacement of missing teeth. This article closely examines the many interdisciplinary issues that arise when treatment planning the placement of single-tooth implants in patients with congenitally missing lateral incisors. The specific criteria that must be evaluated illustrate the importance of an interdisciplinary treatment approach to achieve optimal esthetics and long-term predictability. This is the final article of a three-part series discussing the three treatment alternatives for replacing congenitally missing lateral incisors.

CLINICAL SIGNIFICANCE

When treatment planning single-tooth implants to replace congenitally missing lateral incisors, an interdisciplinary approach is necessary to provide the most predictable treatment outcome.

Managing congenitally missing lateral incisors. Part II: tooth-supported restorations

Three treatment options exist for the replacement of congenitally missing lateral incisors: canine substitution, a tooth-supported restoration, or a single-tooth implant. Selecting the appropriate treatment option depends on the malocclusion, the anterior relationship, specific space requirements, and the condition of the adjacent teeth. The ideal treatment is the most conservative alternative that satisfies individual esthetic and functional requirements. This article closely examines the three options when replacing a missing lateral incisor with a tooth-supported restoration. These options are a resin-bonded fixed partial denture, a cantilevered fixed partial denture, and a conventional full-coverage fixed partial denture. The specific criteria that must be evaluated for each option is addressed to illustrate the importance of interdisciplinary treatment planning to achieve optimal esthetics and long-term predictability. This article is the second of a three-part series discussing the three treatment alternatives for replacing congenitally missing lateral incisors.

Implant-supported single-tooth restorations: a 5-year prospective study

BACKGROUND

Comparatively few studies are available reporting at least 5 years of follow-up data of implant-supported single-tooth replacements.

OBJECTIVE

To evaluate prospectively the 5-year outcome of implant-supported single-tooth prosthetic restorations.

MATERIAL AND METHODS

Forty subjects (mean age 41 years), 23 males and 17 females, who required single-tooth prosthetic replacement for a missing tooth were recruited. A total of 45 self-tapping implants (Astra Tech ST-implants)--40 in the maxilla and five in the mandible--were installed in a two-stage procedure. Abutment connection was performed 3-6 months after implant installation. Clinical and radiographic examinations were performed at the completion of the prosthetic treatment and once a year during a 5-year follow-up period. The analysis of peri-implant bone level alteration was performed on subject and implant levels and by the use of analysis of variance and binary logistic regression.

RESULTS

Three patients were lost during the 5 years of follow-up. One implant was lost after 2.5 years in function and another four implants could not be accounted for at the 5-year follow-up examination. The overall failure rate at 5 years was 2.6% (subject level) and 2.3% (implant level). The mean loss of marginal bone at the implants during the first year in function was 0.06 mm (SD 0.67) on the subject level and 0.02 mm (0.65) on the implant level. During the subsequent 4 years the annual change in peri-implant bone level amounted to -0.02 mm (0.22) on both subject and implant levels. Thus, the mean total bone level change over the 5-year interval was -0.14 mm (1.04) on subject level and -0.11 mm (1.00) on the implant level of analysis (p>0.05). The frequency of implants with a 5-year bone loss of > or =1 mm was 13%. Approximately 50% of the implants demonstrated no bone loss.

CONCLUSION

The present clinical trial on single-tooth replacements with the Astra Tech implant system demonstrated that the bone loss during the first year of function as well as annually thereafter was small.

Factors Associated with Implant Recommendation for Single-Tooth Replacement

The use of dental implants for single-tooth replacement has been established as a predictable treatment option; yet, limited data are available as to how frequently this option is recommended to patients. The aim of the present study was to examine the frequency of implant recommendation by general dental practitioners after single-tooth extraction and factors influencing their decision to recommend an implant. All single-tooth extractions performed in 26 general dental practice clinics in Kuwait over a 30-day period were examined. Dentists in these centers used the study form to record demographic data, the type of tooth extracted, reason for extraction, and replacement options presented to the patients. Univariate and logistic regression analyses were used to examine associations between background factors and decisions to recommend implant therapy. A total of 1367 patients (mean age, 37.9 +/- 11.8 years) had an extraction of one tooth during the study period. Forty-three patients were offered implants as a replacement option (3.3% of the total sample; 8.6% of patients who were offered tooth replacement options). Factors associated significantly with the recommendation of an implant by Kuwaiti dentists to their patients included younger age, regular dental maintenance visits, and adequate oral hygiene practices (P < 0.05; binary logistic regression). Dental implant recommendation for single-tooth replacement in the present sample of dentists was low. Factors associated significantly with dentist recommendation of an implant for single-tooth replacement included age, history of dental maintenance, and oral hygiene practices.