10-year survival and success rates of 511 titanium implants with a sandblasted and acid-etched surface: a retrospective study in 303 partially edentulous patients

Primary stability and osseointegration comparing a novel tapered design tissue-level implant with a parallel design tissue-level implant. An experimental in vivo study

OBJECTIVES

The aim of the present study was to compare a novel tapered, double-threaded self-tapping tissue-Level design implant (TLC) to a well-established parallel walled tissue-level (TL) implant in terms of primary and secondary stability over time.

MATERIALS AND METHODS

Test TLC (n = 10/per timepoint) and control TL (n = 10/per timepoint) implants were placed in the mandible of minipigs and left for submerged healing for 3, 6, and 12 weeks. Maximum insertion torque and implant stability quotient (ISQ) were measured for each implant at placement. Osseointegration and cortical bone maintenance were histologically evaluated by measuring total bone-to-implant contact (BIC) and first bone-to-implant contact (fBIC).

RESULTS

A significantly higher maximum insertion torque was measured for the test implant TLC compared to the control TL implant (57.83 ± 24.73 Ncm and 22.62 ± 23.16 Ncm, respectively; p < .001). The mean ISQ values were comparable between the two implant types (75.00 ± 6.70 for TL compared to 75.40 ± 3.20 for TLC, p = .988). BIC was comparable between both implant types at each of the evaluated time points. The fBIC was found to be significantly more coronal at 12 weeks for the TLC implant compared to the TL implant (0.31 ± 0.83 mm for TLC compared to -0.22 ± 0.85 for TL, p = .027).

CONCLUSION

The novel tapered tissue level design implant showed improved primary stability and an overall improved crestal bone height maintenance compared to the parallel walled design at 12 weeks.

Survey of screw-retained versus cement-retained implant restorations used in both education and private dental practices

AIMS

In the literature, it is still unclear if the decisions for selecting the type of implant crown-retaining system are based on scientific-based research or if the Universities' choices, Implant marketing trends, or finances could have a major influence on the private dentists' decisions.

OBJECTIVES

Therefore, this study aimed to evaluate the crown-retaining system (cement- or screw-retained) used in dental schools and private dental practices.

METHODS

A 13-item questionnaire was sent to Canadian dental schools (n = 10) and dental offices in London (n = 298), Canada. The questionnaire included demographic questions and questions to reveal the dentists' perspectives on prosthetic implant treatment between the two-retaining systems. Results were analyzed using descriptive statistics and multinomial logistic regression (p = 0.05).

RESULTS

Twenty-four private dentists and five dental schools responded to the survey - 62.5% of private practitioners and 60% of universities reported using both systems. A trend was observed in using screw-retained systems by dentists who graduated 5-10 years ago. Straumann, Astra, and Nobel Biocare were the private practices and dental schools' preferred implant systems. The use of platform switching for all cases was selected by 54.2% of the private practitioners and 40% of the dental schools. Resin cement was the private practice's preferred cementation method; the dental schools used glass ionomer and zinc phosphate cement. The multinomial logistic regressions showed no statistical difference between the crown-retaining system chosen and the decision factors. The laboratory technician's recommendations and cost influenced the decision-making process for private dentists. For the universities, perio-restorative outcome, implant position, survival rates, institute preferences, and evidence-based research influenced the crown-retaining system's decision-making process.  CONCLUSION: The Canadian dental schools and private practice reported using both screw- and cement-retaining systems. However, there was a difference in the selection criteria as the universities showed a tendency towards a more research-based approach in their decision, while for the private practices, the technicians' recommendations and cost played a major role in the decision process. It was noted that the implant systems preconized by the Universities were observed to be used in private practices.

Clinical and radiographic performance of late placed and early loaded dental implants with a conditioned hydrophilic surface in posterior mandible sites: A prospective case series with an 8.5- to 9.5-year follow-up

OBJECTIVE

To assess the clinical outcomes by means of implant and prosthetic survival of late placed and early loaded implants with a hydrophilic, moderately rough surface for partially edentulous patients after a follow-up of 8.5 to 9.5 years.

MATERIALS AND METHODS

A prospective case series study involving 15 patients with single, late placed and early loaded implants in the posterior mandible was performed. Clinical and radiographical parameters, including biological and technical complications and patient satisfaction, were assessed.

RESULTS

From an initial sample of 15 patients, 12 were included. A total of 16 implants were observed. After a mean follow-up of 9 years and 7 months (SD ± 3.8 months), implant success and survival rate were 100%. The prosthetic survival rate was 100%, and the prosthetic success rate was 93.8% since a major chipping was observed. No biological complications were observed, and the mean modified plaque index was 0.03 (SD ± 0.09) with a mean probing pocket depth of 2.95 mm (SD ± 0.09). A mean marginal bone level (MBL) of 0.04 mm (SD ± 0.88) and a mean VAS of 9.42 (SD ± 0.90) for patient satisfaction were recorded.

CONCLUSION

Late placed and early loaded implants with a moderately rough endosseal surface are a reliable option for rehabilitating partially edentulous patients. An implant survival rate of 100% and a prosthodontic success rate of 93.8% were observed. Patient satisfaction scores were high and peri-implant hard and soft tissues remained healthy. The study findings should be carefully interpreted because of the small sample.

Radiographic evaluation of marginal bone levels around implants supporting splinted fixed bridges: A retrospective study on 412 implants

OBJECTIVES

The effect of the implant position within the prosthesis on bone remodeling is scarcely documented so far. Thus, the aim of the present study was to investigate whether central implants may suffer higher peri-implant marginal bone levels (MBL) compared to laterals in case of fixed splinted bridges supported by ≥ three implants.

MATERIALS AND METHODS

Partially edentulous subjects rehabilitated with at least one fixed bridge supported by ≥ three dental implants were enrolled. MBL was assessed radiographically by means of intraoral radiographs acquired with phosphor plates and imported in a dedicated software. MBL was calculated as the distance between the implant platform level and the most coronal visible bone-to-implant contact. A three-level linear mixed effects model was used for investigating the fixed effect of patient-, prosthesis-, and implant-level variables on the MBL.

RESULTS

Overall, 90 patients rehabilitated with 130 splinted fixed bridges supported by 412 implants were included. The median follow-up was 136 months. The mean peri-implant MBL resulted statistically significantly higher at central implants if compared to lateral implants (p < .01). The estimated MBL averages for central and external implants were 1.68 and 1.18 mm, respectively. The prosthesis-level variables suggested that a cement-retained bridge was prone to a significant 0.82 mm higher MBL than a screw-retained one. Implant surface showed an association with MBL changes, although less pronounced than implant retention.

CONCLUSIONS

In case of ≥3 adjacent implants supporting splinted bridges, central implants were more predisposed to MBL compared to laterals. At the prosthesis level, implants supporting cement-retained bridges were statistically more susceptible to MBL compared to screw-retained ones. Surface characteristics can also influence MBL stability at the implant level.

Maintaining tooth-implant distance following root amputation of a compromised adjacent tooth: A clinical case report

BACKGROUND

Edentulous sites with limited horizontal tooth-implant distance pose a challenge to clinicians. This case report describes root amputation of an adjacent compromised molar to maintain an optimal tooth-implant distance METHODS AND RESULTS: A 41-year-old female was referred for extraction and implant placement to replace her left, maxillary second premolar (#13), which had been diagnosed with a vertical root fracture. Extraction and ridge preservation of #13 was completed without complication. The 4-month postsurgical clinical examination revealed a narrow mesial-distal distance (5.69 mm) of the edentulous space (#13), which was influenced by the degree of divergence of the mesial buccal root of tooth #14. Cone-beam computed tomography (CBCT) analysis verified a periapical lesion on the mesial-buccal root of tooth #14. The amputation of the endodontically compromised mesial-buccal root of #14 was treatment planned to provide space and facilitate placement of a standard diameter implant without compromising the implant or adjacent teeth. Crestal bone levels were verified and maintained at the 1 year postoperative follow-up.

CONCLUSION

The findings of the case report demonstrate how root amputation of a compromised molar is an alternative solution for managing spatial limitations in contemporary implant dentistry. More studies are required to assess the reliability and long-term success of this approach.

KEY POINTS

Why is this case new information? There is insufficient evidence on the long-term efficacy of narrow-diameter implants. Clinical treatment guidelines are not sufficiently available. This paper presents an alternative approach to managing a specific scenario where mesial-distance distance is limited using root amputation of an adjacent compromised tooth. What are the keys to successful management of this case? Comprehensive diagnosis and stringent case selection Multidisciplinary treatment planning Evidence-based decision making What are the primary limitations to success in this case? Very specific clinical application; adjacent compromised tooth Long-term follow up is required.

A comparison of accuracy among different approaches of static-guided implant placement in patients treated with mandibular reconstruction: A retrospective study

OBJECTIVE

This study aimed to evaluate the differences in the accuracy of immediate intraoral, immediate extraoral, and delayed dental implant placement with surgical guides (static computer-aided implant surgery) in patients treated with mandibular reconstruction.

METHODS

This was a retrospective study. The patients were divided into three groups: immediate intraoral placement (IIO), immediate extraoral placement (IEO), and delayed placement (DEL). Four variables were used to compare the planned and actual implant positions: angular deviation, three-dimensional (3D) deviation at the entry point of the implant, 3D deviation at the apical point of the implant, and depth deviation.

RESULTS

The angular deviation was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .05) groups. The 3D deviation at the entry point was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .01) groups. The 3D deviation at the apical point was significantly higher in the IIO group than in the IEO (p < .01) and DEL (p < .01) groups. The depth deviation was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .05) groups. There was no statistical difference between the IEO and DEL group in angular and 3D deviation.

CONCLUSION

With surgical guides, among the different approaches for implant placement, delayed implant placement remains the most accurate approach for patients treated with mandibular reconstruction.

Clinical performance of immediately placed and immediately loaded single implants in the esthetic zone: A systematic review and meta-analysis

OBJECTIVES

The aim of this study was to assess the following PIO question: In adult patients treated with an indication for single tooth extraction in the maxillary esthetic zone (15-25), what is the influence of an immediate implant placement and immediate loading protocol on the clinical performance (primary aim) and esthetic outcomes (secondary aim) focusing on investigations published after 2010.

MATERIAL AND METHODS

An electronic search in Medline (PubMed), the Cochrane Central Register of Controlled Trials, and EMBASE databases up to April 2022 was performed to identify clinical studies investigating the outcome of single implants subjected to immediate placement with immediate restoration/loading (Type 1A).

RESULTS

Sixty-three studies (10 randomized controlled trials, 28 prospective and 25 retrospective cohort studies) were included with a follow-up ranging from 12 to 96 months. One thousand nine hundred sixty-one implants reported survival rates of 99.2 (98.6-99.5) % at 1 year, 97.5 (95.9-98.4) % after 3 years, and 95.8 (93.3-97.4) % after 5 years; 1064 immediately loaded restorations presented survival rates of 98.9 (97.8-99.5) % after 1 year, 96.8 (93.6-98.4) % after 2 years, and 94.8 (89.6-97.4) % after 5 years. Comparing baseline to 12-month data using the Hedges' g effect size (95% CI), papilla height presented an overall effect size of -0.71 (-1.25, -0.1) mm, midfacial recession change of -0.15 (-0.66, 0.36) mm, and a 0.82 (0.37, 1.28) gain in PES.

CONCLUSIONS

Immediate implant placement and immediate loading can be considered a predictable and safe treatment option for single maxillary anterior restorations with adequate survival rates and favorable esthetics outcomes for up to 5 years.

Influence of buccal bone wall thickness on the peri-implant hard and soft tissue dimensional changes: A systematic review

BACKGROUND

The significance on the association between the peri-implant bucco-lingual dimension (BLD) at the stage of implant placement and the occurrence of biological and esthetic complications is yet unknown.

MATERIAL AND METHODS

Systematic screening of electronic sources was carried out to identify clinical and preclinical studies reporting on the baseline BLD and/or buccal bone thickness (BBT) values. A secondary objective was to assess the effect of simultaneous grafting at sites with deficient or no buccal bone wall (BBW) at baseline. The primary outcome variables were BBT, BLD, and buccal vertical bone loss (VBL) at re-evaluation. Moreover, radiographic, clinical, and patient-reported outcome measures (PROMs) were evaluated.

RESULTS

Overall, 12 clinical and four preclinical studies met the inclusion criteria. Inconsistencies were found in defining the critical BBT across the clinical and preclinical data evaluated. The clinical evidence demonstrated that during healing, dimensional changes occur in the alveolar bone and in the BBW that may compromise the integrity of the peri-implant bone, leading to VBL and mucosal recession (MR), particularly in scenarios exhibiting a thin BBW. The preclinical evidence validated the fact that implants placed in the presence of a thin BBW, are more prone to exhibit major dimensional changes and VBL. Moreover, the clinical data supported that, in scenarios where dehiscence-type defects occur and are left for spontaneous healing, greater VBL and MR together with the occurrence of biologic complications are expected. Furthermore, the augmentation of dehiscence-type defects is associated with hard and soft tissue stability. PROMs were not reported.

CONCLUSIONS

Dimensional changes occur as result of implant placement in healed ridges that may lead to instability of the peri-implant hard and soft tissues. Sites presenting a thin BBW are more prone to exhibit major changes that may compromise the integrity of the buccal bone and may lead to biologic and esthetic complications.

Implant survival/success and peri-implant outcomes of titanium-zirconium mini implants for mandibular overdentures: Results from a 1-year randomized clinical trial

OBJECTIVE

To report the 1-year implant survival/success and peri-implant outcomes of mandibular overdentures retained by four titanium-zirconium mini implants (Straumann® Mini Implant System), and to assess how surgery and loading protocols influence these outcomes.

MATERIALS AND METHODS

A 2 × 2 factorial randomized clinical trial (RCT) tested the combined effects of two loading protocols (immediate or delayed) and two surgical approaches (flapless or flapped) on the success/survival of the mini implants, and peri-implant parameters (plaque, bleeding, sulcus depth, gingival position, and marginal bone loss). Outcomes were assessed up to 1-year after loading, and generalized estimating equations (GEEs) were used to analyze longitudinal and within-patient clustered data.

RESULTS

Two hundred and ninety-six implants were placed in 74 patients. The implant survival/success rates after 1 year were 100%, and no major biological complications were observed. After 1-year, descriptive data suggest no noticeable changes in plaque scores, whilst a reduction in bleeding scores at the 6-month and 1-year follow-ups compared to baseline. Good longitudinal stability was observed for the probing depth and gingival margin height measures. Overall mean marginal bone loss was 0.68 (±0.68) mm after 3 months and 0.89 (±0.75) mm after 1-year. The flapless protocol showed better results on soft tissue stability and health but a slightly higher risk for marginal bone loss.

CONCLUSION

The results of this RCT suggest that mandibular overdentures retained by this novel mini implant system represent a safe and predictable treatment option as confirmed by implant survival/success and peri-implant outcomes, even when flapless surgery and immediate loading protocols are adopted.

Significance of buccal bone wall thickness on the fate of peri-implant hard and soft tissues: A systematic review

BACKGROUND

The significance of the association between the peri-implant buccolingual dimension (BLD) at the stage of implant placement and the occurrence of biological and esthetic complications is yet unknown.

MATERIAL AND METHODS

Systematic screening of electronic sources was carried out to identify clinical and preclinical studies reporting on the baseline BLD and/or buccal bone thickness (BBT) values. A secondary objective was to assess the effect of simultaneous grafting at sites with deficient or no buccal bone wall (BBW) at baseline. The primary outcome variables were BBT, BLD, and vertical bone loss (VBL) at re-evaluation. Moreover, radiographic, clinical- and patient-reported outcome measures (PROMs) were evaluated.

RESULTS

Overall, 12 clinical and four preclinical studies met the inclusion criteria. The clinical evidence demonstrated that during healing, dimensional changes occur in the alveolar bone and in the BBW that may compromise the integrity of bone around a dental implant. The preclinical evidence validated the fact that implants placed in the presence of thin BBW are more prone to exhibit major dimensional changes. Moreover, the clinical and preclinical data supported that in scenarios where dehiscence-type defects are left for spontaneous healing, greater VBL and mucosal recession (MR) together with the occurrence of biologic complications are expected. Furthermore, the augmentation of dehiscence-type defects is associated with hard and soft tissue stability.

CONCLUSIONS

Dimensional changes occur as a result of implant placement in healed ridges that may lead to VBL and MR. Thin BBW (≲2 mm) are prone to exhibit major postchanges that may compromise the integrity of the buccal bone, biologic and esthetic complications.

Influence of drilling sequence and guide-hole design on the accuracy of static computer-assisted implant surgery in extraction sockets and healed sites-An in vitro investigation

OBJECTIVES

To evaluate the effect of drilling sequence, guide-hole design, and alveolar ridge morphology on the accuracy of implant placement via static computer-assisted implant surgery (sCAIS).

MATERIALS AND METHODS

Standardized maxillary bone models including single-tooth gaps with fresh extraction sockets or healed alveolar ridge morphologies were evaluated in this study. Implants were placed using different drilling sequences (i.e., complete [CDS] or minimum [MDS]), and guide-hole designs (i.e., manufacturer's sleeve [MS] or sleeveless [SL] guide-hole designs). The time for implant placement via sCAIS procedures was also recorded. The angular, crestal, and apical three-dimensional deviations between planned and final implant positions were digitally obtained. Statistical analyses were conducted by a non-parametric three-way ANOVA (α = .05).

RESULTS

Based on a sample size analysis, a total of 72 implants were included in this study. Significantly higher implant position accuracy was found at healed sites compared to extraction sockets and in SL compared to MS guide-hole design in angular, crestal, and apical 3D deviations (p ≤ .048). A tendency for higher accuracy was observed for the CDS compared to the MDS, although the effect was not statistically significant (p = .09). The MDS required significantly shorter preparation times compared with CDS (p < .0001).

CONCLUSION

Implant placement via sCAIS resulted in higher accuracy in healed sites than extraction sockets, when using SL compared to MS guides, and tended to be more accurate when using CDS compared to MDS. Therefore, even though surgery time was shorter with MDS, its use should be limited to strictly selected cases.

Survival rates of ultra-short (<6 mm) compared with short locking-taper implants supporting single crowns in posterior areas: A 5-year retrospective study

Background

Short and ultra‐short implants represent a predictable treatment, in terms of implant survival, with patients presenting insufficient available bone volumes. Moreover, single crown restorations represent a gold standard in terms of oral hygiene.

Purpose

The aim of this retrospective study was to evaluate implant survival, marginal bone loss, and peri‐implant complications in 333 locking‐taper short and ultra‐short implants.

Materials and Methods

Implants were placed in the maxillary and mandibular posterior regions of 142 patients. Clinical and radiographic examinations were performed at 5‐year recall appointments.

Results

All implants placed consisted of 8.0‐, 6.0‐, and 5.0‐mm length, 38.14%, 34.53%, and 27.33%, respectively. Three hundred thirty‐two implants (one early failure) were rehabilitated with single crowns in 141 patients. In 45.48% of the implants the crown‐to‐implant ratio was ≥2, with a mean value of 1.94. Overall implant‐based survival after 5 years of follow‐up was 96.10%: 96.85%, 95.65%, and 95.60% for 8.0‐, 6.0‐, and 5.0‐mm length implants, respectively (p = 0.82). Overall patient‐based survival was 91.55%. Regarding crestal bone level variations, average crestal bone loss and apical shift of the “first bone‐to‐implant contact point” position were 0.69 and 0.01 mm, respectively. Setting the threshold for excessive bone loss at 1 mm, during the time interval from loading to follow‐up, 28 implants experienced loss of supporting bone greater than 1 mm: 19 of them (67.85%) were surgically treated with a codified surgical regenerative protocol. After 60 months, a peri‐implantitis prevalence of 5.94% was reported, with an overall implant success of 94.06%: 95.93%, 92.73%, and 93.10% for 8.0‐, 6.0‐, and 5.0‐mm length implants, respectively (p = 0.55).

Conclusion

Long‐term outcomes suggest that short and ultra‐short locking‐taper implants can be successfully restored with single crowns in the posterior area of the maxilla and mandible.