A systematic review of single-tooth restorations supported by implants

Survival of immediate implants replacing traumatised teeth in the anterior maxilla

Aim The provision of implants following traumatic dental injuries can hold many challenges, primarily in higher aesthetic regions. The purpose of this retrospective study was to assess the clinical outcomes of immediate implants placed in fresh extraction sites in the anterior maxilla following dental trauma.Materials and methods In total, 60 patients requiring teeth replacement with dental implants in the anterior maxilla were included in the study. Following a delayed loading protocol, the implants were restored with definitive single crowns or bridges. Implant and prosthetic survival, complications and periodontal health were recorded during follow-up.Results A total of 70 implants were placed in the anterior maxilla with three failures reported, resulting in an implant survival rate of 95.7% over a follow-up period of three years. No additional bone augmentation was undertaken and prosthetic survival recorded was 100%, with favourable periodontal outcomes achieved overall.Conclusion This study showed that implants immediately inserted into fresh extraction sites following dental trauma can constitute a predictable treatment strategy, presenting high implant survival rates over the follow-up period observed. Further well-designed controlled clinical trials are required to evaluate longer-term outcomes for this technique.

Reoperation on an Implant-Supported Restoration in the Maxillary Anterior Region to Correct a Complex Aesthetic Deficit

Introduction

In an era in which patients are becoming more and more demanding and in which there are many ways to satisfy their needs, modern implantology must consider the correct management of soft tissues during treatment planning, aiming for both functional and aesthetic rehabilitation while creating a prosthetic construction that is in harmony not only with the natural dentition of the patient but also with their face. The patient who came to our notice had a rehabilitative prosthetic implant on the left central incisor area, which did not satisfy any functional or aesthetic parameter. Furthermore, he presented an altered passive eruption in the contralateral hemiarch.

Materials and Methods

The prosthetic crown was removed, the tissues were studied, and the team decided to proceed with customizing a provisional restoration that would cause the soft tissues to descend. A surgical periodontal procedure was then performed to solve the altered passive eruption condition that was also compromising the aesthetics. In conclusion, a permanent prosthetic crown was fixed into place. Discussion. Using a periodontal approach that was both surgical and prosthetic, the patient was rehabilitated correctly regaining both functions and aesthetics. It is of fundamental importance that each step in the procedure is carefully programmed; otherwise, the risk of making mistakes increases and solving the problems becomes less simple or less immediate. In order to do this, one must bear in mind that certain clinical cases can apparently concern just one tooth, yet the mouth must be considered as a whole, both functionally and aesthetically. To perform an optimal implantology, the clinician should be an expert in periodontology so that they can plan and, should it be necessary, perform all the therapeutical options (surgical and nonsurgical) that can lead to the best possible result.

Conclusions

The resolution of this complex clinical case has been documented in order to share useful advice for the resolution of analogous cases. We strongly advise that each proposed procedure be planned meticulously and that the periodontological aspect of the case never be separated from the prosthetic or the implantological aspects since the integration of the periodontal tissues is of vital importance for both the functional and the aesthetic results.

Autologous Tooth Graft after Endodontical Treated Used for Socket Preservation: A Multicenter Clinical Study

The aim of the study was to evaluate the tooth extracted use as autologous tooth graft after endodontic root canal therapies used for socket preservation. To this purpose, the Tooth Transformer shredding and decontamination machine has been used. The graft obtained in this way, was inserted at the time of the extraction or at a second surgery altogether with the chosen regenerative therapy. This clinical trial enrolled patients with post-estractive defects requiring the restoration bone dimension and shape in the maxillary and mandibular zone. In addition, 98 patients with 119 extraction sockets were enrolled across 10 standardized centers. An innovative preparation method, using the dedicated automated device Tooth Transformer, able to transform autologous teeth in suitable grafting material, has been used. The extracted tooth was cleaned and treated using a Tooth Transformer and made a socket preservation. Thirteen Biopsies were realized to analyze the histologic outcomes at the average time of four months to demonstrate that the autologous tooth graft made from root after endodontic therapy should be used in human bone regeneration as graft for dental implant placement.

Full-mouth rehabilitation with immediate loading basal implants: A case report

The aim of this article was to study a case report of full mouth rehabilitation in a severally periodontally compromised patient in which 18 single piece basal implants were inserted and functionally loaded with both maxillary and mandibular cement retained fixed partial denture. Basal implants were loaded immediately, and excellent results were obtained. Bone loss was measured and values were recorded immediately after implant placement and after 6 months. Basal implants are used to support single and multiple unit restorations in the upper and lower jaws. They can be placed in the extraction sockets and also in the healed bone. Their structural characteristics allow placement in the bone that is deficient in height and width. Basal implants are the devices of the first choice, whenever (unpredictable) augmentations are part of an alternative treatment plan. The technique of basal implantology solves all problems connected with conventional (crestal) implantology.

Frequency of Technical Complications in Fixed Implant Prosthesis: The Effect of Prosthesis Screw Emergence Correction by Computer-Aided Design/Computer-Aided Manufacturing

Computer-aided design/computer-aided manufacturing (CAD-CAM) technology permits the angular correction of screw emergence into the prosthesis; however, there is lack of controlled clinical studies that assess the frequency of technical complications in angled screw channel restorations. This controlled clinical study was designed to assess technical incidences in angled screw channel restorations. Patients who underwent placement of implant prosthesis between November 2014 and December 2015 were screened. The patients were selected if they received a prosthesis with up to 30° correction of the prosthesis screw emergence and had at least 1 nonangulated prosthesis (screw retained). All prostheses were located completely/partially in the posterior region. The frequency of technical complications was the principal variable. A total of 52 patients with a mean age of 62 ± 10 years participated, with a total of 110 prostheses (55 in the test group and 55 in the control group). A total of 11 technical complications occurred (7 in the test group and 4 in the control group). These differences were not statistically significant. All prostheses in both groups survived the follow-up. The correction of the screw emergence into the prosthesis has not increased the risk of technical complications in CAD-CAM implant prostheses.

A Comparison between Piezoelectric Devices and Conventional Rotary Instruments in Bone Harvesting in Patients with Lip and Palate Cleft: A Retrospective Study with Clinical, Radiographical, and Histological Evaluation

Introduction

Orofacial clefts are congenital malformations characterized by an incomplete shaping of structures that separate the nasal from the oral cavity and can affect the right, left, or both sides. The aim of the present study is to assess, with clinical, radiographical, and histological evaluations, the efficacy of piezoelectric devices compared to traditional rotating instruments in the bone harvesting in patients with history of cleft.

Materials and Methods

We have conducted a retrospective analysis on 20 patients with a history of orofacial clefts that were operated on from February 2014 to June 2017. The patients were divided into two groups: Group R in which bone graft was harvested using a burr and Group P in which the bone graft was obtained by a piezoelectric device. After a healing period of 8 months from the grafting procedure, clinical and radiographic evaluations were performed.

Results and Discussion

The use of the piezoelectric devices in bone harvesting allows a slight improvement in the final volume. This supports a faster integration into the receiving site.

Conclusions

The use of piezoelectric device in patients with history of orofacial cleft that needed bone graft represents a method to be taken into consideration because it has interesting advantages.

Implant and root canal treatment: Survival rates and factors associated with treatment outcome

OBJECTIVES

To assess and compare the survival rates of implant and root canal treatment as well as to investigate the effect of patient and tooth related variables on the treatment outcome in a large-scale population-based study.

METHODS

Dental records of patients who received root canal treatment and implant therapy were retrieved from the electronic records of the University of Minnesota School of Dentistry. Demographic characteristics, dental insurance status, socioeconomic status as well as medical history and tobacco use were recorded. The treatment outcome was included as a binary variable (survival/failure).

RESULTS

A total of 13,434 records of patients who had implant (33.6%) or root canal therapy (66.4%) were included. The survival rate analysis and Kaplan-Meier table revealed the majority of the implants were removed within the first year (58.8%), while only 35.2% of the root canal treatments failed in the same time period. The overall survival rate was significantly (p < 0.001) higher for implant therapy (98.3%) compared to root canal treatment (72.7%). A statistically significant association was found between treatment (p <n0.001), age (p < 0.001) and anxiety (p = 0.004) with treatment outcome CONCLUSIONS: Implant therapy exhibited significantly lower failures when compared to root canal treatment, but the selection of either treatment should be based on multiple factors. Higher age and anxiety were also significantly associated with root canal and implant treatment failure.

CLINICAL SIGNIFICANCE

Clinicians are in an increased dilemma that affects the decision-making process due to the inadequate evidence in regards to the question of retention or extraction of a tooth in the natural dentition. This study demonstrated that both root canal and implant treatments are sound options with high survival rates; however, root canal therapy exhibited a significantly higher failure rate.

Esthetic Outcomes of Immediately Loaded Locking Taper Implants in the Anterior Maxilla: A Case Series Study

The purpose of this study was to evaluate the esthetic outcome of single-tooth locking taper connection implants placed in the anterior maxilla following a postextractive nonfunctional loading protocol. This preliminary clinical study involving 16 patients evaluated the results of 21 implants placed in areas with high esthetic value. For each implant the pink esthetic score, white esthetic score, cumulative survival rate, and health status of peri-implant tissues were evaluated. The cumulative survival rate was 100% 2 years after prosthetic loading, and the mean total pink esthetic score/white esthetic score was 16.9 ± 1.14 on a maximum value of 20. There was excellent plaque control in all patients, and inflammation indices were within the norm. Within the limits of this study, this immediate nonfunctional loading protocol seems to be a successful procedure esthetically and for the maintenance of peri-implant soft tissues.

Multiple immediate implants placement with immediate loading

The replacement of missing teeth with implant-borne restorations has become a treatment modality accepted by the scientific community for fully and partially edentulous patients. Recent reports have demonstrated the successful placement of dental implants into the fresh extraction socket in the anterior as well as in molar regions, which is made possible due to modification in implant surface. The present case report highlights the placement of three bicortical screw (BCS) implants into the fresh extraction sockets and one KOS implant in edentulous area with flapless technique. All the implants were immediately loaded and followed up for a period of 6 months.

A novel multi-phosphonate surface treatment of titanium dental implants: a study in sheep

The aim of the present study was to evaluate a new multi-phosphonate surface treatment (SurfLink^®) in an unloaded sheep model. Treated implants were compared to control implants in terms of bone to implant contact (BIC), bone formation, and biomechanical stability. The study used two types of implants (rough or machined surface finish) each with either the multi-phosphonate Wet or Dry treatment or no treatment (control) for a total of six groups. Animals were sacrificed after 2, 8, and 52 weeks. No adverse events were observed at any time point. At two weeks, removal torque showed significantly higher values for the multi-phosphonate treated rough surface (+32% and +29%, Dry and Wet, respectively) compared to rough control. At 52 weeks, a significantly higher removal torque was observed for the multi-phosphonate treated machined surfaces (+37% and 23%, Dry and Wet, respectively). The multi-phosphonate treated groups showed a positive tendency for higher BIC with time and increased new-old bone ratio at eight weeks. SEM images revealed greater amounts of organic materials on the multi-phosphonate treated compared to control implants, with the bone fracture (from the torque test) appearing within the bone rather than at the bone to implant interface as it occurred for control implants.

A prospective cohort study on the impact of smoking on soft tissue alterations around single implants

OBJECTIVES

To compare smokers to non-smokers in terms of soft tissue alterations following single implant treatment in healed bone.

MATERIAL AND METHODS

Non-smoking and smoking patients with sufficient bone volume in need of a single implant in the anterior maxilla (15-25) were consecutively recruited in three centres. Conventional single implant surgery was performed and an immediate provisional crown was installed. Eight to 12 weeks later, the latter was replaced by a permanent one (baseline). Papilla regrowth and midfacial recession was registered after 2 years of function.

RESULTS

The sample consisted of 39 non-smokers (21 females; mean age 42) and 46 smokers (22 females; mean age 45). Smokers had three early failures, whereas all implants integrated successfully in non-smokers. Statistically significant papilla regrowth was observed in non-smokers (distal 0.63 mm, mesial 0.76 mm), whereas smokers showed stable papillae (between cohorts: P ≤ 0.025). Midfacial soft tissue level demonstrated statistically significant regrowth in non-smokers (0.53 mm), whereas it remained stable in smokers (between cohorts: P = 0.004).

CONCLUSION

Smokers failed to demonstrate papilla regeneration and showed more midfacial recession following single implant treatment when compared to non-smokers.

Buccal bone deficiency in fresh extraction sockets: a prospective single cohort study

OBJECTIVE

The purpose of this prospective single cohort study was to evaluate the use of xenograft and collagen membranes in treating full or partial buccal bone defects of fresh extraction sockets in the esthetic zone.

MATERIALS AND METHODS

Thirty-three patients requiring tooth extraction in the anterior maxillary area and showing a complete or partial buccal bone plate deficiency (more than 2 mm) were consecutively enrolled and treated. Corticocancellous porcine bone and platelet-rich fibrin (PRF) with a collagen membrane were used to graft the extraction sockets, and the membranes were left exposed to the oral cavity with a secondary soft tissue healing. The outcome variables were as follows: width of keratinized mucosa, facial soft tissue levels, clinical bone changes (measured with a clinical splint), implant and prosthesis failures, and peri-implant marginal bone changes.

RESULTS

All treated sites allowed the placement of implants; the width of keratinized mucosa at the mid-facial aspect showed an increase of 2.3 mm 5 months after the grafting procedure, and its value was 3.2 ± 0.6 mm at 1-year follow-up. The mean values of the facial soft tissue level indicated an increase over time. The bone level showed an improvement of 0.8 ± 0.1 mm and 0.7 ± 0.1 mm at mesial and distal sites, respectively, when compared to the baseline measurements. Finally, in the palatal area, no bone changes were observed. No implant failed during the entire observation period.

CONCLUSIONS

Findings from this study showed that xenograft and PRF, used for ridge preservation of the extraction sockets with buccal bone plate dehiscence in the esthetic zone, can be considered effective in repairing bone defects before implant placement. The secondary soft tissue healing over the grafted sockets did not compromise bone formation; moreover, the soft tissue level and the width of keratinized gingiva showed a significant improvement over time.

Effect of the implant-abutment interface on peri-implant tissues: a systematic review

OBJECTIVE

The aim of the present systematic review was to determine the peri-implant tissue response to different implant abutment materials and designs available and to assess the impact of tissue biotype.

MATERIALS AND METHODS

Relevant literature published between December 2009 and August 2012 was searched to identify studies dealing with different implant abutment designs and materials, as well as the response of different tissue biotypes. The search terms used, in simple or multiple conjunctions, were 'implant abutment', 'interface', 'material', 'peri-implant', 'soft tissue' and 'esthetic'. Studies were selected according to pre-determined inclusion and exclusion criteria.

RESULTS

The initial search yielded 2449 titles. After a subsequent filtering process, 23 studies were finally selected. The included studies revealed different factors responsible for the stability of peri-implant tissue and the esthetic outcome. These factors include tissue biotype and architecture, implant abutment material and implant abutment design. Several designs were suggested to prevent marginal bone loss and soft tissue recession. These included scalloped implants, platform-switched implants and gingivally converged or concave implant abutments. Due to the limited number of studies and the heterogeneity in their designs, it was not possible to perform a statistical analysis of the data.

CONCLUSIONS

The current literature provides insufficient evidence about the effectiveness of different implant abutment designs and materials in the stability of peri-implant tissues.

Clinical and Aesthetic Outcome with Post-Extractive Implants with or without Soft Tissue Augmentation: A 2-Year Randomized Clinical Trial

BACKGROUND

The aesthetic outcome of an implant-supported restoration is first of all dependent on the soft tissue volume. Because the labial bone plate resorbs in every direction after tooth extraction, even when an implant is placed immediately, most patients end up with compromised aesthetics.

MATERIALS AND METHODS

In this parallel-designed, randomized clinical trial, participants were randomly assigned to the test group (immediate load post-extractive implant treated with subepithelial connective tissue graft placed using the tunnel technique in the labial area) and control group (immediate load post-extractive implant treated without raising a flap) with an allocation ratio of 1:1. Both groups received deproteinized bovine bone mineral. Patients were observed at baseline, crown insertion, 1-year follow-up, and 2-year follow-up. Clinical, radiological and aesthetic parameters were recorded to assess primary treatment outcomes. A random permuted block system was blindly generated ensuring uniformity of the patient allocation during the trial by randomly distributing three participants to the test and three participants to the control group every six treated patients.

RESULTS

At the 2-year examination, all 47 implants were successfully integrated, demonstrating stability and healthy peri-implant soft tissues as documented by standard clinical parameters. The results showed a soft tissue remodeling of -10% in thickness and -18% in highness in the non-grafted group, whereas in the grafted group there was a gain of 35% in thickness and a slight reduction of -11% in highness. Test group reported an increase of aesthetic result (mean pink aesthetic score [PES] 8) compared with control group (mean PES 6.65).

CONCLUSIONS

This prospective study demonstrates the effectiveness of placing a soft tissue graft at the time of immediate implant placement in the aesthetic zone. At the 2-year follow-up, test group revealed a better aesthetic outcomes and stable facial soft tissues compared with control group.

Oral diagnosis and treatment planning: part 7. Treatment planning for missing teeth

Although more people are retaining increasing numbers of their natural teeth into older ages, approximately 30-40% of persons over the age of 75 years in Western countries are edentulous. The causes and significance of tooth loss vary widely among individuals and cultures, and missing teeth may be replaced by a variety of means for functional, social and psychological reasons, rather than for significant physical health benefits. Therefore, it is essential to determine what the loss of teeth means to patients and what their expectations are for the outcomes following tooth replacement by various methods.

Influence of abutment material and luting cements color on the final color of all ceramics

PURPOSE

The purpose of this study is to evaluate the effects of different abutment materials and luting cements color on the final color of implant-supported all-ceramic restorations.

MATERIALS AND METHODS

Ten A2 shade IPS e.max Press disc shape all-ceramic specimens were prepared (11 × 1.5 mm). Three different shades (translucent, universal and white opaque) of disc shape luting cement specimens were prepared (11 × 0.2 mm). Three different (zirconium, gold-palladium and titanium) implant abutments and one composite resin disc shape background specimen were prepared at 11 mm diameter and appropriate thicknesses. All ceramic specimens colors were measured with each background and luting cement samples on a teflon mold. A digital spectrophotometer used for measurements and data recorded as CIE L*a*b* color co-ordinates. An optical fluid applied on to the samples to provide a good optical connection and measurements on the composite resin background was saved as the control group. ΔE values were calculated from the ΔL, Δa and Δb values between control and test groups and data were analyzed with one-way variance analysis (ANOVA) and mean values were compared by the Tukey HSD test (α = 0.05).

RESULTS

One-way ANOVA of ΔL, Δa, Δb and ΔE values of control and test groups revealed significant differences for backgrounds and seldom for cement color groups (p the 0.05). Only zirconium implant abutment groups and gold palladium abutment with universal shade cement group were found to be clinically acceptable (ΔE ≤ 3.0).

CONCLUSION

Using titanium or gold-palladium abutments for implant supported all ceramics will be esthetically questionable and white opaque cement will be helpful to mask the dark color of titanium abutment.

Methodological quality and descriptive characteristics of prosthodontic-related systematic reviews

Ideally, healthcare systematic reviews (SRs) should be beneficial to practicing professionals in making evidence-based clinical decisions. However, the conclusions drawn from SRs are directly related to the quality of the SR and of the included studies. The aim was to investigate the methodological quality and key descriptive characteristics of SRs published in prosthodontics. Methodological quality was analysed using the Assessment of Multiple Reviews (AMSTAR) tool. Several electronic resources (MEDLINE, EMBASE, Web of Science and American Dental Association's Evidence-based Dentistry website) were searched. In total 106 SRs were located. Key descriptive characteristics and methodological quality features were gathered and assessed, and descriptive and inferential statistical testing performed. Most SRs in this sample originated from the European continent followed by North America. Two to five authors conducted most SRs; the majority was affiliated with academic institutions and had prior experience publishing SRs. The majority of SRs were published in specialty dentistry journals, with implant or implant-related topics, the primary topics of interest for most. According to AMSTAR, most quality aspects were adequately fulfilled by less than half of the reviews. Publication bias and grey literature searches were the most poorly adhered components. Overall, the methodological quality of the prosthodontic-related systematic was deemed limited. Future recommendations would include authors to have prior training in conducting SRs and for journals to include a universal checklist that should be adhered to address all key characteristics of an unbiased SR process.

Papillae alterations around single-implant restorations in the anterior maxillae: thick versus thin mucosa

To evaluate the papilla alterations around single-implant restorations in the anterior maxillae after crown attachment and to study the influence of soft tissue thickness on the papilla fill alteration. According to the inclusion criteria, 32 patients subjected to implant-supported single-tooth restorations in anterior maxillae were included. The patients were assigned to two groups according to the mucosal thickness: (i) group 1, 1.5 mm s mucosal thickness 3 mm; and (ii) group 2, 3 mm<mucosal thickness 4.5 mm.Assessments of interproximal papillae at the time of crown placement (baseline) and at 6-month post loading (follow-up) were made by two prosthodontists using papilla fill index (PFI). The mean mucosal thickness was (2.49±_0.31) mm (group 1) and (3.81±_0.31) mm(group 2) for the two groups respectively. A significant difference in PFI between the groups was detected at the baseline (P<0.001).PFI improvements over time occurred after 6-month follow-up irrespective of the groups. When compared to group 1, the likelihood to obtain papilla fill was significantly higher for group 2 with an odds ratio of 6.05 (P<0.001). The interproximal papilla level around single-implant restorations could improve significantly over time after 6-month restoration according to PFI assessment. The thicker mucosa before implant placement implied a more favorable esthetic outcome in papilla alteration.

Impact of vertical loading on the implant-bone interface

OBJECTIVES

The main aim of this study was to evaluate the impact of vertical loading occurring during removal of cemented restorations on the implant-bone interface.

METHODS

Thirty-six titanium implants (Camlog 4.3 × 9 mm) were placed 1 mm supraosseous in the frontal skull of four minipigs. After a 13 week healing period the implants were exposed and the implant stability was measured. Three implants per minipig were vertically loaded using 20 or 100 impulses, respectively with an 18 Ns impulse imitating a crown removal. Three implants were left unloaded as control. The animals were sacrificed after 13 or 18 weeks. The harvested specimens were analyzed using scanning electron microscopy (SEM), light and fluorescence microscopy.

RESULTS

No post operative complications or deaths of the minipigs occurred. All implants osseointegrated. The average bone-implant contact area (BIC) was 78 ± 5.1%. No statistically significant difference could be found when comparing the BIC areas of the control and the experimental groups between the sacrificed animals at 13 weeks and 18 weeks (P > 0.05). Therefore, the results of each subgroup were pooled. No significant differences regarding the BIC area could be detected between the control and the experimental groups (P > 0.05). Except one failing implant no cracks due to vertical loading could be evaluated in the SEM. Fluorescence microscopy revealed a significantly higher bone remodeling activity in the vertically loaded groups.

CONCLUSIONS

Removal of cemented implant restorations seems not to have an impact on the mechanical implant stability, but seems to increase bone remodeling activity.

A systematic review on the frequency of advanced recession following single immediate implant treatment

PURPOSE

It has been stated that midfacial recession is common following immediate implant treatment (IIT). The objective of this systematic review was to assess the frequency of advanced recession (>1 mm) following single IIT.

MATERIAL AND METHODS

An electronic search in Pubmed, Web of Science and the Cochrane Oral Health Group Specialized Trials Register database was performed using a search algorithm. Reference lists of relevant articles were also scrutinized to identify prospective studies on ≥10 implants installed in patients with an intact buccal bone wall and followed for ≥12 months. Study eligibility and quality were independently assessed by two investigators. Primary outcome variables were advanced inter-proximal and midfacial recession defined as soft tissue loss surpassing 1 mm between the pre- or postoperative status and the final re-assessment.

RESULTS

Thirteen of 171 papers were selected. Inter-examiner agreement on eligibility (κ = 0.879; p < 0.001) and quality (κ = 0.788; p < 0.001) was high. Advanced inter-proximal recession was described in 0-27% of the cases. However, these data were only based on two studies. Mean inter-proximal recession was frequently reported (11/13) and was <1 mm in all studies suggesting limited risk for advanced inter-proximal recession. Advanced midfacial recession was described in 0-64% of the cases. Again, few papers provided such information (4/13). Only one of these studies demonstrated high risk for advanced midfacial recession (>10%). This could be attributed to the fact that implants had not been restored with an immediate implant crown, which seems of pivotal importance given the results of a randomized controlled trial reporting on the preserving effect of immediate provisionalization on midfacial mucosa level. There is limited evidence to support an increased risk for midfacial recession following flap surgery and in patients with a thin-scalloped gingival biotype. The impact of implant-specific parameters on inter-proximal and midfacial soft tissue level seems conflicting.

CONCLUSIONS

Soft tissue recession may be expected following IIT and multiple factors seem to contribute to the phenomenon. Taking into account the paucity of papers, patients with an intact buccal bone wall and thick gingival biotype, treated by means of flapless surgery and an immediate implant crown may demonstrate limited risk for advanced midfacial recession (<10%). Proper risk assessment addressing diagnostic, surgical and restorative aspects is mandatory to avoid compromised outcome of IIT.

Natural Tooth Versus Implant: A Key to Treatment Planning

Since time immemorial, man has constantly contrived to replace natural body parts that are either congenitally absent or lost subsequent to disease or injury, so as to maintain a perfect amalgam of form and function. Dental implants have recently become established as a standard treatment protocol for replacing missing teeth. Ostensibly, a dilemma has arisen whether the implant should obviate the necessity to preserve teeth with debatable restorative prognosis. This article attempts to review the work done hitherto and to formulate a combined perspective in such cases.

Four modalities of single implant treatment in the anterior maxilla: a clinical, radiographic, and aesthetic evaluation

PURPOSE

To document the outcome of single implants in the anterior maxilla following four routine treatment modalities when performed by experienced clinicians in daily practice using the same implant system and biomaterials.

MATERIAL AND METHODS

A retrospective study in patients who had been treated by two periodontists and two prosthodontists in 2006 and 2007 was conducted. The four treatment modalities practically covered every clinical situation and included standard implant treatment (SIT), immediate implant treatment (IIT), implant treatment in conjunction with guided bone regeneration (GBR), and implant treatment in grafted bone (BGR) harvested from the chin. All implants were installed via flap surgery. Patients were clinically and radiographically examined. Complications were registered and the aesthetic outcome (pink esthetic score [PES] and white esthetic score [WES]) was rated. A blinded clinician who had not been involved in the treatment performed all evaluations. Patient's aesthetic satisfaction was also registered.

RESULTS

One hundred four out of 115 eligible patients (44 SIT, 28 IIT, 18 GBR, and 14 BGR) received at least one single NobelReplace tapered TiUnite® (Nobel Biocare, Göteborg, Sweden) implant in the anterior maxilla and were available for evaluation. Clinical parameters (implant survival: 93%, mean plaque level: 24%, mean bleeding on probing: 33%, and mean probing depth: 3.2 mm) and mean bone level (1.19 mm) did not differ significantly between treatment modalities. Postoperative complications were more common following GBR/BGR (>61%) when compared with SIT/IIT (<18%) (p < .001). BGR was in 4/14 patients associated with permanent sensory complications at the donor site. Technical complications occurred in 9/104 patients. SIT and IIT showed similar soft tissue aesthetics (PES: 10.07 and 10.88, respectively), however major alveolar process deficiency was common (>15%). PES was 9.65 for GBR. BGR showed inferior soft tissue aesthetics (PES: 9.00; p = .045) and shorter distal papillae were found following GBR/BGR (p = .009). Periodontal disease (odds ratio [OR]: 13.0, p < .001), GBR/BGR (OR: 4.3, p = .004), and a thin-scalloped gingival biotype (OR: 3.7, p = .011) increased the risk for incomplete distal papillae. WES was 7.98 for all patients considered. Poor agreement was found between objective and subjective aesthetic ratings.

CONCLUSIONS

All treatment modalities were predictable from a clinical and radiographic point of view. However, advanced reconstructive surgery, especially BGR, increased the risk for complications and compromised aesthetics. Research is required on the prevention and minimally invasive treatment of buccal bone defects at the time of tooth loss to avoid complex therapy.

Influence of the interface design on the yield force of the implant-abutment complex before and after cyclic mechanical loading

PURPOSE

The aim of this in vitro study was to evaluate the implant-abutment assembly of Astra Tech (AST), Bego (BEG), Camlog (CAM), Friadent (FRI), Nobel Biocare (NOB) and Straumann (STR) with respect to yield force before and after cyclic fatigue, using a static overload test with a test set-up according to ISO 14801.

METHODS

Ten specimens of each type were split into two homogenous groups: one half was tested for static yield force without any further treatment (control), whereas the other one underwent one million cycles of mechanical loading with 100N as the upper load limit. For load-to-failure testing, specimens were then placed in a stainless steel jig and loaded in a universal testing machine under an angle of 30° with respect to the implant axis until failure. Load-displacement curves were analyzed and the yield forces at which non-linear behaviour set in (Fp) were recorded. Statistical analysis was performed using one-way ANOVA and t-test, respectively, with the level of significance set at 0.05.

RESULTS

Statistical analysis revealed that the type of implant-abutment connection has a significant influence on Fp (p<0.001). Furthermore, dynamic loading proved to significantly influence Fp of BEG and CAM (p<0.001).

CONCLUSION

None of the implant-abutment types tested would be expected to fail under clinically relevant forces, but the type of implant-abutment connection significantly influences the yield force Fp.

Correlation between occlusal forces and marginal bone levels around implant-retained restorations: a clinico-radiological study

The study measured the maximal occlusal forces (MOFs) and marginal bone levels (MBLs) around single implant-retained restorations over a period of 1 year and studied the correlation between them. Results showed that there was no change in MOFs at the end of 1 year and that the MBLs were stabilized by the end of 1 year. There was no statistically significant correlation between MOFs and MBLs.

Trauma to an implant-supported crown that was saved by the fixation screw: a case report

A traumatic impact to an implant-supported crown might damage the implant, restoration and peri-implant tissues. Ideally, only a small prosthetic retreatment is needed for restoration, as complicated prosthetic retreatments or surgical retreatments in particular, could be very inconvenient for the patient. However, there is a deficiency in literature on how the implant, restoration and surrounding tissues generally react to impact forces. This report demonstrates a case of trauma to an implant-supported crown in the maxillary anterior zone resulting in a displacement of the implant crown. After careful examination and follow-up, it appeared that only the fixation screw was damaged, whereas the implant, restoration and peri-implant tissues remained unharmed. Thanks to the protective qualities of the implant system, an easy prosthetic retreatment could restore the implant-supported crown and a surgical retreatment was prevented.

Tooth survival following non-surgical root canal treatment: a systematic review of the literature

AIMS

To investigate (i) the effect of study characteristics on reported tooth survival after root canal treatment (RCTx) and (ii) the effect of clinical factors on the proportion of root filled teeth surviving after RCTx.

METHODOLOGY

Longitudinal human clinical studies investigating tooth survival after RCTx which were published up to the end of 2007 were identified electronically (MEDLINE and Cochrane database 1966-2007 December, week 4). In addition, four journals (Dental Traumatology, International Endodontic Journal, Journal of Endodontics, Oral Surgery Oral Medicine Oral Pathology Oral Radiology & Endodontics), bibliographies of all relevant articles and review articles were hand searched. Two reviewers (Y-LN, KG) assessed and selected the studies based on specified inclusion criteria and extracted the data onto a pre-designed proforma, independently. The criteria were as follows: (i) clinical study on RCTx; (ii) stratified analysis of primary and secondary RCTx available; (iii) sample size given and larger than 10; (iv) at least 6-month postoperative review; (v) success based on survival of tooth; and (vi) proportion of teeth surviving after treatment given or could be calculated from the raw data. Three strands of evidence or analyses were used to triangulate a consensus view. The reported findings from individual studies, including those excluded for quantitative analysis, were utilized for the intuitive synthesis, which constituted the first strand of evidence. Secondly, the pooled weighted proportion of teeth surviving and thirdly the combined effects of potential prognostic factors were estimated using the fixed and random effects meta-analyses on studies fulfilling all the inclusion criteria.

RESULTS

Of the 31 articles identified, 14 studies published between 1993 and 2007 were included. The majority of studies were retrospective (n = 10) and only four prospective. The pooled percentages of reported tooth survival over 2-3, 4-5 and 8-10 years following RCTx were 86% (95% CI: 75%, 98%), 93% (95% CI: 92%, 94%) and 87% (95% CI: 82%, 92%), respectively. Substantial differences in study characteristics were found to hinder effective direct comparison of findings. Evidence for the effect of prognostic factors on tooth survival was weak. Based on the data available for meta-analyses, four conditions were found to significantly improve tooth survival. In descending order of influence, the conditions increasing observed proportion of survival were as follows: (i) a crown restoration after RCTx; (ii) tooth having both mesial and distal proximal contacts; (iii) tooth not functioning as an abutment for removable or fixed prosthesis; and (iv) tooth type or specifically non-molar teeth. Statistical heterogeneity was substantial in some cases but its source could not be investigated because of insufficient available information.

CONCLUSIONS

The pooled proportion of teeth surviving over 2-10 years following RCTx ranged between 86% and 93%. Four factors (listed above) were identified as significant prognostic factors with concurrence between all three strands of evidence.

Endodontic and implant algorithms

Dental professionals are often faced with challenges when formulating a treatment plan for patients presenting with a compromised tooth. A common dilemma involves the decision between tooth retention using endodontic treatment with crown restoration, and extraction and an implant-borne restoration. In this article the authors evaluate the 2 treatment modes, and observe that because outcomes are similar with both treatments, decisions should be based on the patient's informed decision concerning restorability, costs associated with the procedures, esthetics, potential adverse outcomes, and ethical factors.

Cost-effectiveness modeling of dental implant vs. bridge

AIMS

We assess the cost-effectiveness of dental implant first-line strategy vs. fixed partial denture strategy in patients suffering from one single missing tooth.

MATERIALS AND METHODS

The model used a simulation decision framework over a 20-year period. Potential treatment switches can occur every 5 years. Transition probabilities come from literature, epidemiological reports or expert opinions. They have been programmed using specific distribution ranges to simulate the patients' and practice variability, and to take into account parameter uncertainty. Direct medical costs have been assessed according to a cost survey. Probabilistic sensitivity analyses were conducted using 5000 Monte-Carlo simulations, generating confidence intervals of model outcomes.

RESULTS

We found that mean cost-effectiveness of the bridge strategy is higher than the implant strategy.

CONCLUSION

Implant as the first-line strategy appears to be the 'dominant' strategy, considering the lower overall costs and the higher success rate.