Soft and hard tissue evaluation of guided socket shield implant cases

BACKGROUND

The socket-shield (SS) technique results in long-term functional osseo- and dento-integration, preserving the dimensional stability of hard and soft tissues over time. This study aimed to describe the successful implementation of a surgical technique to facilitate "SS" cases.

METHODS

The cases included males and females aged 32-81 years consecutively treated between 2020 and 2023 (longest follow-up, 3.5 years). For each case, pre- and post-operative cone-beam computed tomography (Digital Imaging and Communications in Medicine files) and intraoral optical scans (IOS; STL files) were performed. Digital immediate implant placement and simultaneous tooth extraction and SS production were planned using an implant planning software. Implants were planned considering sagittal-ridge and tooth-root angular-configuration. Surgical guides were used to perform the digitally-supported SS technique. All cases were planned and surgically performed by one operator (Pedro M. Trejo). Preoperative digital IOS-models were superimposed to post-operative models to assess soft-tissue changes. Pre and post sagittal views were used to assess the radiographic buccal-plate thickness at various healing times. An investigator not involved with case planning or treatment performed measurements.

RESULTS

Results reflected soft-tissue stability with minimal mean thickness change at 0-, 1-, 2-, and 3-mm measurement levels of 0.03, -0.2, 0.14, -0.07, and 0.04 mm, respectively, with a mean gingival-margin change of 0.04 mm. The free gingival-margin change ranged from a 0.58-mm gain in height to a -0.57-mm loss. The mean radiographic buccal-plate thickness post-operatively was 2.04 mm (range, 0.7-2.9 mm).

CONCLUSION

The digitally-supported guided SS technique enables predictable immediate implant-placement positions and stable buccal peri-implant soft and hard tissues over time.

KEY POINTS

Why are these cases new information? The uniqueness of the surgical technique described herein is that it results in favorable positions of immediate, socket-shielded (SSed), implant placements, with soft- and hard-tissue stability as the byproduct. What are the keys to successful management of these cases? Digitally, plan for the best possible implant position within the alveolar housing to satisfy prosthetic requirements, and then adjust this position to accommodate the socket shield dimensions. Digitally, provide a space/gap between the future dentinal shield and the implant. Clinically, allow for time to carve the final position and dimensions of the shield. Plan ahead the extent of the apical third of the SS, and the removal of the apex, if dealing with a long root. What are the primary limitations to success in these cases? Inadequate use of digital technology; case-sensitive technique requires proper execution of each digital and technical clinical step.

Orthodontic maximum anchorages in malocclusion treatment: A systematic review and network meta-analysis

OBJECTIVE

We did a network meta-analysis and systematic review among patients seeking for maximum anchorage and provided a guidance of selecting certain systems in clinical practice.

METHODS

Seven databases were searched, and randomized controlled trials (RCTs) published with no language restrictions from January 1994 to February 2021 comparing any of the following seven anchorage systems for maximum anchorage orthodontic treatment were selected(PROSPERO: CRD42019117995). A network meta-analysis (NMA) was then conducted to integrate direct evidence with indirect evidence based on logical inference to compare and rank treatments for maximum anchorages in the capacity of maintaining anchorage and duration of total treatment time.

RESULTS

Nine publications with 522 participants were considered eligible and were taken into evaluation. According to the capacity of anchorage reinforcement, three skeleton anchorages including miniscrew implants, midpalate implants and Onplant midpalate implants were significantly more effective than conventional anchorages including headgears, TPAs and Nance buttons respectively. According to conventional anchorages, headgears and Nance buttons were significantly more effective than TPA. The strategy ranking reflected the same results as above. However, miniscrew implants required the longest total treatment time.

CONCLUSIONS

In general, miniscrew impants are most effective in reserving anchorage. Nance buttons require the least total treatment time. Total evidence is graded as moderate. Midpalatal implants might be the best choice when doing treatment planning because it has the most favorable balance between effectiveness and treatment time. But data analysis of the acceptability and acquisition cost of those anchorage systems must be done to make final decisions.

Systematic review and pooled analysis of survival rates, success, and outcomes of osseointegrated implants in a variety of composite free flaps

The aim of this review was to provide an update on survival rates of osseointegrated implants into common composite free flaps used for maxillary and mandibular reconstructions and identify factors affecting outcomes. PubMed, Medline, Embase, and Cochrane databases were searched. Included studies reported implant survival by flap type. Results were pooled and survival was estimated with the Kaplan-Meier method. Variables affecting survival were assessed using Cox regression. Thirty-two of the 2631 articles retrieved were included, totaling 2626 implants placed into fibula, iliac crest, scapula, and radial forearm free flaps. Pooled survival showed 94% 5-year survival of implants in fibula and iliac crest with no difference between groups (P = .3). Factors effecting survival included radiotherapy (HR 2.3, 95% CI 1.2-4.6, P = .027) and malignant disease (HR 2.2, 95%CI 1.6-3.1, P < .001). Implant survival appears adequate across common flap types; however, there are limited numbers reported in less common flaps.

How Thick Is the Oral Mucosa around Implants after Augmentation with Different Materials: A Systematic Review of the Effectiveness of Substitute Matrices in Comparison to Connective Tissue Grafts

This systematic review aimed to assess the effectiveness of xenogeneic collagen matrices (XCMs) and acellular dermal matrices (ADMs) in comparison to connective tissue grafts (CTGs) for the augmentation of oral mucosa around dental implants. MEDLINE and the Web of Science were searched for clinical studies that compared substitute materials for the augmentation of oral mucosa to the subepithelial connective tissue graft around dental implants during or after implantation. The review was conducted according to the recommendations of the PRISMA statement. From an initial search result set of 1050 references, seven articles were included in the review. The study designs were heterogeneous, so no meta-analysis could be performed. Both the CTG and either type of substitute material resulted in increased mucosal thickness. Four studies showed no significant difference, while three demonstrated a significant difference, favoring the CTGs over alternative materials. Soft tissue augmentation around dental implants is a safe procedure and leads to thicker mucosal tissue. The subepithelial connective tissue graft can still be regarded as the gold standard, but substitute materials may be an acceptable alternative in some situations, such as for pain-sensitive patients, among inexperienced surgeons, and for sites with an already thick biotype.

Histological healing outcomes at the bone-titanium interface of loaded and unloaded dental implants placed in humans: A systematic review of controlled clinical trials

Purpose: The purpose of this systematic review was to assess the histological healing outcomes at the bone–titanium interface of loaded and unloaded dental implants placed in humans. Materials and methods: An electronic search was conducted using the PubMed, Embase and Cochrane Central Register of Controlled Trials (Central) databases up to and including April 2020 to identify clinical trials reporting human histological data of bone healing around titanium dental implants placed in healed alveolar ridges. The search was conducted by two independent reviewers with no language restrictions. The risk of bias of each included study was assessed using the Cochrane Collaboration’s domain-based, two-part tool. Results: Of the 4564 potentially eligible articles, only 25 were included in this systematic review (13 randomised and 12 controlled clinical trials), with a total of 548 micro/transitional implants evaluated. The marked heterogeneity between studies did not allow the data to be combined for meta-analyses. In general, based on mean values of bone-to-implant contact (range 9% to 73%), bone density outside the threaded area (range 14.9% to 31.6%), bone density in the threaded area (range 17.9% to 56.9%) and osteocyte index (range 19.79 to 37.88 cells/mm2), all implant surface modifications demonstrated osseointegration potential. Furthermore, immediate loading was related to higher bone-to-implant contact, bone density outside the threaded area and osteocyte index; longer healing periods to higher bone-to-implant contact; and smoking to lower bone-to-implant contact, bone density in the threaded area and bone density outside the threaded area. Conclusions: Despite the fact that several modifications were made to the implant surface, when considering the values for bone-to-implant contact, bone density in the threaded area, bone density outside the threaded area and osteocyte index, machined surfaces showed the worst healing outcomes. Nevertheless, osseointegration was improved by both immediate loading and longer healing periods and worsened by smoking.

Immediate functional loading of single implants: a multicenter study with 4 years of follow-up

Background. In the current scientific literature there are only few studies on the immediate functional loading of single implants. The aim of the present present study was to evaluate the 4-year survival rate, complication rate and peri-implant marginal bone loss (PIMBL) of immediately loaded single implants inserted in healed ridges and fresh post-extraction sites.

Methods. Six centers were involved in this prospective study. The surgical and prosthetic protocol was defined in detail, before the start of recruiting patients. Recruitment of patients and performance of surgeries took place between February 2012 and February 2013. Criteria for inclusion were single-tooth gaps in healed ridges and fresh post-extraction sockets. All the fixtures (Anyridge®, Megagen Corporation, Gyeongbuk, South Korea) were functionally loaded immediately after insertion and followed for a period of 4 years. Outcome measures were implant survival, complications and PIMBL.

Results. Forty-six patients (18‒73 years of age) were selected. In total, 57 fixtures were placed (10 in fresh post-extraction sockets). After 4 years of functional loading, only one fixture was lost; therefore, high survival rates (97.6% patient-based; 98.1% implant-based) were reported. In addition, a limited incidence of biologic (4.8% patient-based; 3.8% implant-based) and prosthetic (9.7% patient-based; 7.6% implant-based) complications was reported. The overall 4-year PIMBL amounted to 0.38±0.21 mm (healed ridges: 0.4±0.21 mm; fresh post-extraction sockets: 0.33±0.20 mm).

Conclusion. Loading single implants immediately seems to be a highly successful treatment modality. However, long-term data are needed to confirm these positive outcomes.

Efficacy of standard (SLA) and modified sandblasted and acid-etched (SLActive) dental implants in promoting immediate and/or early occlusal loading protocols: a systematic review of prospective studies

OBJECTIVE

To assess the survival percentage, clinical and radiographic outcomes of sandblasted and acid-etched (SLA) dental implants and its modified surface (SLActive) in protocols involving immediate and early occlusal loading.

METHODS

MEDLINE, EMBASE and the Cochrane Oral Health Group's Trials Register CENTRAL were searched in duplicate up to, and including, June 2013 to include randomised controlled trials (RCTs) and prospective observational studies of at least 6-month duration published in all languages. Studies limited to patients treated with SLA and/or SLActive implants involving a treatment protocol describing immediate and early loading of these implants were eligible for inclusion. Data on clinical and/or radiographic outcomes following implant placement were considered for inclusion.

RESULTS

Of the 447 potentially eligible publications identified by the search strategy, seven RCTs comprising a total of 853 implants (8% titanium plasma-sprayed, 41.5% SLA and 50.5% SLActive) and 12 prospective observational studies including 1394 SLA and 145 SLActive implants were included in this review. According to the Cochrane Collaboration's tool for assessing risk of bias, one of the studies was considered to be at a low risk of bias, whereas the remaining studies were considered to be at an unclear risk. Regarding the observational studies, all of them presented a medium methodological quality based on the Modified Newcastle-Ottawa scale. There were no significant differences reported in the studies in relation to implant loss or clinical parameters between the immediate/early loading and delayed loading protocols. Overall, 95% of SLA and 97% of SLActive implants still survive at the end of follow-up.

CONCLUSIONS

Despite of the positive findings achieved by the included studies, few RCTs were available for analysis for SLActive implants. Study heterogeneity, scarcity of data and the lack of pooled estimates represent a limitation between studies' comparisons and should be considered when interpreting the present findings.

Effects of tobacco smoking on the survival rate of dental implants placed in areas of maxillary sinus floor augmentation: a systematic review

OBJECTIVES

The objective of this systematic review was to evaluate the effects of smoking on the survival rate of dental implants placed in areas of maxillary sinus floor augmentation.

MATERIAL AND METHODS

The Cochrane Oral Health Group's Trials Register (CENTRAL), MEDLINE and EMBASE were searched in duplicate up to, and including, October 2012 without language restrictions. Studies were considered eligible for inclusion if they involved the treatment of smokers and non-smokers with titanium implants and sinus floor elevation procedures. The Newcastle-Ottawa Scale and the Cochrane Collaboration's quality assessment tool were used for the assessment of the risk of bias in included studies. Random effects meta-analyses were used to assess the number of implants lost in smokers vs. number of implants lost in non-smokers.

RESULTS

Of 3360 potentially eligible papers, eight studies were included. More than half (62.5%) of the studies found that smoking adversely affects implant survival in sites of sinus floor augmentation. Similarly, the pooled analysis indicated a statistically significantly increased risk of implant failure in smokers when the outcomes of all studies available to be included into meta-analysis were evaluated [RR: 1.87 (95% CI: 1.35, 2.58), P = 0.0001]. Conversely, a subgroup analysis including only prospective studies (3 studies) did not reveal significant differences in implant failure between smokers and non-smokers [RR: 1.55 (95% CI: 0.91, 2.65), P = 0.11].

CONCLUSIONS

Although smoking was associated with implant failure in most of individual studies and in the overall meta-analysis, the detrimental effect of smoking was not confirmed when only prospective data were assessed.

A comparison of computed tomography scans and digital periapical radiographs ridge height measurements

To investigate the agreement between computerized tomography scans (CT) and intraoral periapical digital radiographs (PA) alveolar ridge height measurements in maxillary and mandibular posterior regions. We reviewed 100 implant patient radiographic records and identified 27 mandibular sites in 19 patients and 23 maxillary sites in 13 patients with available CT scans and matching PA radiographs. The distance from the crest of the ridge to the floor of the maxillary sinus or to the superior border of the inferior alveolar canal was measured. PAs were measured with Dexis software v. 8.0 and CTs were measured with Simplant software v. 11.02. Two examiners (RJ and MM) recorded the measurements separately; each examiner recorded two readings. The average of the 4 readings was used for data analysis. Absolute agreement: Paired t test comparing ridge-height measurements between the two imaging methods showed no differences for maxillary sites (P > 0.2) and significant differences for the mandibular sites (CT > PA, P = 0.0009). Relative agreement: Kendall rank correlation analysis of ridge-height measurements between the 2 imaging methods showed a high positive correlation for maxillary sites (Kendall's tau = 0.76, P = 0.0001) and moderate correlation for the mandibular sites (Kendall's tau = 0.46, P = 0.001). Maxillary PAs tend to approximate CT ridge-height measurements. By contrast mandibular PAs tend to underestimate the distance from the crest of the ridge to the inferior alveolar canal.