Using a Bone Density Measuring Micromotor to Distinguish Different Cortical/Cancellous Combinations in Vitro: A Study Using Polyurethane Foam Blocks

PURPOSE

To assess whether a recently introduced implant placement micromotor that provides site-specific, operator independent cancellous bone density measurements can detect the presence of a cortical bone layer and measure its thickness and density.

MATERIALS AND METHODS

An in vitro experiment was performed on six double-layer polyurethane foam blocks mimicking the jawbone with different cortical thickness/cancellous density combinations. The densities were measured using the micromotor after either removing the cortical layer or leaving it intact, both with and without irrigation.

RESULTS

The results were compared by means of nonparametric statistical tests. Independent of irrigation, the micromotor detected the cortical layer when it was left intact and accurately estimated its thickness. The micromotor did not discriminate between blocks when they were considered separately, but it did when they were grouped into four or three classes.

CONCLUSIONS

The present study suggests that the micromotor may represent a valid device to quantitatively assess bone quality and density. If the micromotor can quantitatively distinguish different cortical/cancellous bone combinations in humans, it may be a helpful tool for performing finely tuned, patient-tailored preparations of the implant seat, making tooth rehabilitation in challenging clinical conditions more predictable.

Is transmucosal healing of an implant as effective as submerged healing when simultaneous guided bone regeneration is performed? A preclinical study

AIM

To investigate whether transmucosal healing is as effective as submerged healing in terms of buccal bone regeneration when guided bone regeneration (GBR) is performed simultaneously with implant placement.

MATERIALS AND METHODS

In six dogs, buccal dehiscence defects were created in the edentulous mandibular ridge, sized 5 × 5 × 3 mm (length × height × depth). In each defect, a bone-level implant was placed, and four experimental groups were randomly assigned as follows: (i) transmucosal healing with GBR (T-GBR), (ii) transmucosal healing without GBR (T-control), (iii) submerged healing with GBR (S-GBR) and (iv) submerged healing without GBR (S-control). Data analyses were based on histological slides 5 months after implant placement.

RESULTS

The T-GBR group showed significant differences compared to the control groups regarding defect height resolution, buccal bone thickness and mineralized tissue area (p < .05), but showed no significant differences when compared with the S-GBR group (p > .05).

CONCLUSIONS

The mode of healing (transmucosal vs. submerged) does not influence bone regeneration at implant sites. The clinician may therefore choose the approach based on further clinical and patient-specific parameters.

Evaluation of Survival Rates of Dental Implants and the Risk Factors: A Retrospective Follow-Up Study

Introduction The current research sets out to assess implant early survival rates and identify relevant parameters. Methods The research spanned the years 2021 and 2022 and included all individuals who had dental implants. Various criteria, such as age, sex, maxilla/mandible, implant location, immediate implant, implant diameter, implant length, and others, were used to determine the implant survival rate in the research. A multiple logistic regression model was used to show the risk variables for early survival rates of implants, and components with p < 0.05 were further included after the Chi-square test was employed to filter them. Results The current research included 128 patients who had a single implant procedure, including 70 males and 58 females. The early survival rate was 91.40%, and 117 implants were retained after implantation. Risk variables that were shown to be associated with early survival rates were patients aged 30-60 years (OR: 2.542), immediate implant placement (OR: 3.742), and implant length less than 10 mm (OR: 3.972). Conclusions Age, tooth location, implant length, and immediate implantation were risk variables that contributed to our subjects' above 91% early survival rate of implants.

Optimizing Osseointegration in Dental Implantology: A Cross-Disciplinary Review of Current and Emerging Strategies

The paper explores the correlation between osteointegration and dental implant stability, investigating the relationship and its implications for successful outcomes in implant dentistry. Osteointegration, defined as the direct structural and functional connection between living bone and the implant surface, plays a crucial role in determining the stability and long-term success of dental implants. This review synthesizes current knowledge from scientific literature and clinical studies to elucidate the factors influencing osteointegration and their impact on implant stability. Surface characteristics of implants, such as topography and chemistry, as well as the surgical techniques employed during implant placement, are examined in detail, emphasizing their significant influence on osseointegration and subsequent implant stability. Additionally, host-related factors such as bone quality, systemic conditions, and patient-specific considerations are explored to further comprehend the complexity of the osteointegration process. The abstract underscores the importance of achieving an optimal bone-implant interface to ensure successful implant integration and stability. Furthermore, emerging technologies and materials, such as computer-guided implant placement and biomimetic surfaces, are discussed for their potential to enhance osteointegration and improve long-term implants.

Critical review on bone grafting during immediate implant placement

In the last 20 years, immediate implant placement has been proposed as a predictable protocol to replace failing teeth. The research conducted in preclinical and clinical studies have focused on soft and hard tissue changes following tooth extraction and immediate implant placement. Different approaches for hard and soft tissue grafting together with provisional restorations have been proposed to compensate tissue alterations. This review analyzed some relevant clinical and preclinical literature focusing on the impact of bone grafting procedures on immediate implant placement in terms of hard and soft tissue changes, aesthetic results, and patient-related outcomes.

Referral Patterns of General Dental Practitioners for Implant Surgery Procedures

PURPOSE

The growing demand for implants has led to their implementation by general dental practitioners (GDPs) in clinical practice. The present study assessed referral patterns of GDPs for the surgical phase of implant dental treatment.

MATERIALS AND METHODS

One hundred fifty GDPs were asked to fill out a structured questionnaire containing their demographic data and answer six questions characterising their referral patterns for implant dentistry.

RESULTS

Forty-one (41%) percent performed the surgical phase, and 87% provided implant restoration. Gender was the only influencing factor for the surgical phase, as 51.4% of male GDPs and 6.5% of female GDPs performed implant surgery themselves. Experience and practice set-up did not influence the referring decision. Fifty-four percent of the practitioners referred 0 to 5 patients per month, and the chosen specialists were: 80% oral and maxillofacial surgeon, 11% periodontist, and 9% selected a specialist depending on the individual case. The major reasons influencing the referral pattern were the complexity of the surgical procedure, followed by systemic medical compromise of the patient.

CONCLUSIONS

Most implant surgeries in Israel are still performed by specialists.

Preformed customized healing abutments in biologically oriented preparation technique procedure: a 3-year retrospective case-control study

AIM

To determine the 3-year clinical and dimensional change of the soft tissue following implant placement in healed sites before and after loading with either customized or conventional healing abutments.

MATERIALS AND METHODS

Premolar/molar implants were immediately loaded with either provisional and customized abutments without finishing lines according to principles of the Biologically Oriented Preparation Technique (BOPT), test group, or conventional healing abutments, control group. Three months later, the definitive crowns were fabricated. Primary outcomes (changes in the soft tissue) and secondary outcomes (adverse events) had been registered.

RESULT

Fifty out of 87 subjects originally included were finally selected for this retrospective analysis: 23 in the test and 27 in the control group. During the first days after surgery 2 adverse events of mucositis, one for each group, occurred. A Few technical complications such as unscrewing 4 screw-retained crowns were recorded. A significant increase in the alveolar width was observed in both groups (test = +2.5±0.5mm, and control = +1.0±0.9mm). The widths appeared to not be merely changed from 3 months to 3 years in both groups. There were no significant differences regarding the width of the keratinized mucosa measured at baseline and after follow-up. Jemt papilla index showed a higher increase in the test group compared with that of the control group.

CONCLUSION

Within 3 years of the follow-up period, peri-implant soft tissue outcomes of single, immediately loaded implants with customized healing abutments showed better results in terms of thickness and width when they were compared with those of the conventional group. Side effects count (mucositis and dehiscence) appeared to be very similar between the two groups. In addition, customized healing abutments led to significant augmentation of the alveolar width more than twice that registered in the conventional group.

Socket shield technique: Stress distribution analysis

Background

To analyze through finite element analysis the stress distribution in peri-implant bone tissues, implants, and prosthetic components induced by the socket shield (SS) technique in comparison to other techniques used to treat tooth loss.

Materials and Methods

A three-dimensional model of a superior central incisor crown supported by implant was modeled and three different placement conditions were simulated: SS - 2.0-mm-thick root dentin fragment positioned between the alveolar buccal wall and implant; heterologous bone graft (HBG) - bovine bone graft positioned the alveolar buccal wall and implant; and control (C) - implant fully placed in bone tissue of a healed alveolus. The model was restricted at the lateral surfaces of the bone tissue and the following loads were simulated: Both oblique (45°) loads of 100 N on the lingual surface of the crown (maximal habitual intercuspation) and 25.5 N on the incisal edge of the crown (tooth contact during mandibular protrusion) were simultaneously applied. Tensile stress, shear stress, compression, and displacement were analyzed in the cortical bone, trabecular bone, dentin root fragment, and bone graft; while equivalent von Mises stresses were quantified in the implant and prosthetic components.

Results

Stress values of SS and HBG in the bone tissues were higher than C, while slight differences within models were observed for dentin root fragment, bone graft, implant, and prosthetic components.

Conclusions

The SS technique presented the highest stress concentration in the peri-implant tissues.

Computer-assisted bone augmentation, implant planning and placement: An in vitro investigation

AIM

To assess in vitro the workflow for alveolar ridge augmentation with customised 3D printed block grafts and simultaneous computer-assisted implant planning and placement.

METHODS

Twenty resin mandible models with an edentulous area and horizontal ridge defect in the region 34-36 were scanned with cone beam computed tomography (CBCT). A block graft for horizontal ridge augmentation in the region 34-36 and an implant in the position 35 were digitally planned. Twenty block grafts were 3D printed out of resin and one template for guided implant placement were stereolithographically produced. The resin block grafts were positioned onto the ridge defects and stabilised with two fixation screws each. Subsequently, one implant was inserted in the position 35 through the corresponding template for guided implant placement. Optical scans of the study models together with the fixated block graft were performed prior to and after implant placement. The scans taken after block grafting were superimposed with the virtual block grafting plan through a best-fit algorithm, and the linear deviation between the planned and the achieved block positions was calculated. The precision of the block fixation was obtained by superimposing the 20 scans taken after grafting and calculating the deviation between the corresponding resin blocks. The superimposition between the scans taken after and prior to implant placement was performed to measure a possible displacement in the block position induced by guided implant placement. The (98-2%)/2 percentile value was determined as a parameter for surface deviation.

RESULTS

The mean deviation in the position of the block graft compared to the virtual plan amounted to 0.79 ± 0.13 mm. The mean deviation between the positions of the 20 block grafts measured 0.47 ± 0.2 mm, indicating a clinically acceptable precision. Guided implant placement induced a mean shift of 0.16 ± 0.06 mm in the position of the block graft.

CONCLUSIONS

Within the limitations of this in vitro study, it can be concluded that customised block grafts fabricated through CBCT, computer-assisted design and 3D printing allow alveolar ridge augmentation with clinically acceptable predictability and reproducibility. Computer-assisted implant planning and placement can be performed simultaneously with computer-assisted block grafting leading to clinically non-relevant dislocation of block grafts.

Local Concentrations of TGF-β1 and IGF-1 Appear Determinant in Regulating Bone Regeneration in Human Postextraction Tooth Sockets

Healing after tooth extraction involves a series of reparative processes affecting both alveolar bone and soft tissues. The aim of the present study was to investigate whether activation of molecular signals during the healing process confers a regenerative advantage to the extraction socket soft tissue (ESsT) at 8 weeks of healing. Compared to subepithelial connective tissue graft (CTG), qRT-PCR analyses revealed a dramatic enrichment of the ESsT in osteogenic differentiation markers. However, ESsT and CTG shared characteristics of nonspecialized soft connective tissue by expressing comparable levels of genes encoding abundant extracellular matrix (ECM) proteins. Genes encoding the transforming growth factor-β1 (TGF-β1) and its receptors were strongly enriched in the CTG, whereas the transcript for the insulin-like growth factor-1 (IGF-1) showed significantly high and comparable expression in both tissues. Mechanical stimulation, by the means of cyclic strain or matrix stiffness applied to primary ESsT cells (ESsT-C) and CTG fibroblasts (CTG-F) extracted from the tissue samples, revealed that stress-induced TGF-β1 not exceeding 2.3 ng/mL, as measured by ELISA, in combination with IGF-1 up to 2.5 ng/mL was able to induce the osteogenic potential of ESsT-Cs. However, stiff matrices (50 kPa), upregulating the TGF-β1 expression up to 6.6 ng/mL, caused downregulation of osteogenic gene expression in the ESsT-Cs. In CTG-Fs, endogenous or stress-induced TGF-β1 ≥ 4.6 ng/mL was likely responsible for the complete lack of osteogenesis. Treatment of ESsT-Cs with TGF-β1 and IGF-1 proved that, at specific concentrations, the two growth factors exhibited either an inductive-synergistic or a suppressive activity, thus determining the osteogenic and mineralization potential of ESsT-Cs. Taken together, our data strongly warrant the clinical exploration of ESsT as a graft in augmentative procedures during dental implant placement surgeries.

Alveolar ridge preservation: A review of concepts and controversies

The loss of thickness and height of the alveolar process after tooth extraction is a significant impediment to implant placement, which limits the aesthetic results of many restorative treatments. Alveolar ridge preservation can reduce bone resorption. Knowing how beneficial this procedure is can help clinicians decide if it is worth doing. The purpose of this article is to present a contemporary review of the different approaches to preserving the dimensions of the alveolar ridge. We analyze the alveolar healing process, atraumatic extraction techniques, graft materials, and controversies.

Development of a framework to assess the biomechanical impact of reverse shoulder arthroplasty placement modifications

Reverse shoulder arthroplasty biomechanics can be improved by modifying the placement of prosthesis. Biomechanical studies have quantified the impact of placement modifications on the mobility and stability of the reverse shoulder. While these studies have provided detailed insights, direct comparisons between their finding are obfuscated by their use of differing methodologies. The aim of our study was to develop an assessment framework which used musculoskeletal simulations to consistently evaluate the biomechanics of various placement modifications. We conducted musculoskeletal simulations of humeral elevations and rotations using 15 reverse shoulder models. For each model, these simulations were conducted for a reference configuration of the prosthesis, established using surgical guidelines, and 34 modified configurations, which were based on commonplace adaptations to the placement of the glenosphere and humeral tray. The effect of each modified configuration on deltoid elongation, deltoid moment arm (DMA), joint stability, and impingement-free range of motion (IFROM) was determined relative to the reference configuration. We found that 16 of the 34 modified placements had an overall beneficial impact on reverse shoulder biomechanics. Within this subset, we identified two biomechanical trade-offs. First, there is an antagonistic relationship between IFROM and both the DMA and joint stability. Second, functional requirements differ between humeral elevations and rotations. Furthermore, we found that posteromedial translation of the humeral tray had the most beneficial impact on joint stability and inferior translation of the glenosphere had the most beneficial impact on IFROM and DMA.

Dimensional ridge changes in conjunction with four implant timing protocols and two types of soft tissue grafts: A pilot pre-clinical study

AIM

To determine the effect of (1) implant placement timing and (2) the type of soft tissue graft in terms of ridge profile changes.

MATERIALS AND METHODS

Four implant treatment modalities were applied in the mesial root areas of the third and fourth mandibular premolars of 10 mongrel dogs alongside connective-tissue graft (CTG) and volume-stable cross-linked collagen matrix (VCMX): immediate, early, and delayed placement (DP), and DP following alveolar ridge preservation (ARP). All dogs were sacrificed 3 months after soft tissue augmentation. Standard Tessellation Language files from designated time points were analysed.

RESULTS

Compared with the pre-extraction situation, the median width of the ridge demontstrated a linear increase only in group ARP/CTG (0.07 mm at the 2-mm level), whereas all other groups showed a reduction (between -1.87 and -0.09 mm, p > .05). Groups ARP/CTG (0.17 mm) and DP/CTG (0.05 mm) exhibited a profilometric tissue gain in a set region of interest (p > .05). The net effect of CTG and VCMX ranged from 0.14 to 0.79 mm.

CONCLUSIONS

Dimensional ridge changes varied between treatment protocols. ARP with CTG led to the smallest difference in ridge profile between the pre-extraction and the study end time point. Both CTG and VCMX enhanced the ridge contour.

Robotic-arm assisted versus manual total hip arthroplasty: Systematic review and meta-analysis of radiographic accuracy

BACKGROUND

We systematically reviewed the radiological outcomes of studies comparing robotic-assisted (RA-THA) and manual total hip arthroplasty (mTHA).

METHODS

The PubMed, Embase, and Cochrane databases were queried from 1994-2021 for articles comparing radiographic outcomes between RA-THA and mTHA cohorts. A meta-analysis was conducted whenever sufficient data was present for common outcomes.

RESULTS

Our analysis included 20 articles reporting on 4140 patients (RA-THA: n = 1228; mTHA: n = 2912). No differences were demonstrated for acetabular inclination or anteversion. However, RA-THA demonstrated higher rates of cup orientation within the Lewinnek and Callanan safe zones, improved femoral stem alignment, and lower global offset difference (GOD) and limb length discrepancy (all p-values <0.05). Superior femoral canal fill and combined offset were seen among RA-THA patients.

CONCLUSION

Our review found that the use of RA-THA yields superior radiographic outcomes compared to mTHA counterparts. This information can inform healthcare systems considering investing in and implementing these technologies.

Effects of Groove Sealing of the Posterior Occlusal Surface and Offset of the Internal Surface on the Internal Fit and Accuracy of Implant Placements Using 3D-Printed Surgical Guides: An In Vitro Study

This study evaluated the internal fit and the accuracy of the implant placement position in order to determine how the surface shape of the tooth and the offset influence the accuracy of the surgical guide. The acquired digital data were analyzed in three dimensions using 3D inspection software. The obtained results confirmed that the internal fit was better in the groove sealing (GS) group (164.45 ± 28.34 μm) than the original shape (OS) group (204.07 ± 44.60 μm) (p < 0.001), and for an offset of 100 μm (157.50 ± 17.26 μm) than for offsets of 30 μm (206.48 ± 39.12 μm) and 60 μm (188.82 ± 48.77 μm) (p < 0.001). The accuracy of implant placement was better in the GS than OS group in terms of the entry (OS, 0.229 ± 0.092 mm; GS, 0.169 ± 0.061 mm; p < 0.001), apex (OS, 0.324 ± 0.149 mm; GS, 0.230 ± 0.124 mm; p < 0.001), and depth (OS, 0.041 ± 0.027 mm; GS, 0.025 ± 0.022 mm; p < 0.001). In addition, the entries (30 μm, 0.215 ± 0.044 mm; 60 μm, 0.172 ± 0.049 mm; 100 μm, 0.119 ± 0.050 mm; p < 0.001) were only affected by the amount of offset. These findings indicate that the accuracy of a surgical guide can be improved by directly sealing the groove of the tooth before manufacturing the surgical guide or setting the offset during the design process.

Monitoring crestal bone level of single- and two-stage implant placement modes up to final prosthetic delivery: an observational study

OBJECTIVES

To monitor and compare the nonsubmerged (single-stage, SS) and submerged (two-stage, TS) implant placement techniques up to the final prosthesis delivery. Marginal bone level and marginal bone loss rate of both surgical techniques were compared.

METHOD AND MATERIALS

Marginal bone level was measured, using an image processing program (ImageJ), from periapical radiographs at the times of placement (T0), exposure (Te), initial loading (T1), and at the final prosthetic delivery (T2), with a total time span of a mean of 13.2 ± 3.3 months. By timing normalization, marginal bone level and marginal bone loss rate (mm/month), following SS and TS implant placement techniques and other local and systemic parameters were analyzed. Asymmetric analyses using Mann-Whitney test followed by the correlation Pearson analyses were applied. A P value < .05 defined statistical significance.

RESULTS

In total, 268 implants (42 patients) were monitored. Marginal bone loss rate was 0.15 ± 0.13 mm and 0.13 ± 0.11 mm, between T0 and T2, for the SS and TS techniques, respectively. Marginal bone level and marginal bone loss rate were higher among smokers for both techniques at various time points. Bruxers had higher marginal bone loss rate than nonbruxers between T0 and T1, and T0 and T2. Marginal bone loss rate around implants that were placed at the posterior maxilla was higher than those at the posterior mandible between T1 and T2. Interproximal implant distance correlated negatively with marginal bone loss rate between T0 and T2 (P < .05).

CONCLUSIONS

The results suggest that both techniques achieved similar clinical outcome. Smoking, bruxism, anatomical location, and interproximal implant distance apparently affect the marginal bone level and marginal bone loss rate of both implant placement approaches. The implant placement surgical mode, combined with various systemic and/or anatomical factors could play a significant role in maintaining marginal osseous level around the implant neck.

Isolation through rubber dam to prevent COVID-19 exposure during flapless trans-crestal sinus lift procedures

In 2020, a highly infective new pathogen (Sars-CoV-2) spread from China to the whole globe, and became responsible of an acute respiratory syndrome, often asymptomatic but potentially lethal, named COVID-19. Airborne and direct contact contamination are the major infection pathways of Sars-CoV-2 and it has been shown that virus spread can also happen in absence of clinical symptoms. SARS-CoV-2 transmission during dental procedures can happen through inhalation of droplets from infected patients or direct contact with mucous membranes, oral fluids, and contaminated instruments. Both sinus lift and implant surgeries often involve bleeding and exposure to oral fluids, and a rubber dam could be used to reduce direct contact and the amount of potentially infected aerosol. The aim of this short case presentation is to illustrate how the use of a rubber dam could be extremely useful in preventing COVID-19 exposure during flapless trans-crestal sinus lift procedures.

Implant Placement in Patients under Treatment with Rivaroxaban: A Retrospective Clinical Study

The management of patients under treatment with Direct Oral Anticoagulants (DOACs) has led clinicians to deal with two clinical issues, such as the hemorrhagic risk in case of non-interruption or the risk of thromboembolism in case of suspension of the treatment. The primary aim of this retrospective study was to evaluate the incidence of perioperative bleeding events and healing complications in patients who were under treatment with Rivaroxaban and who received dental implants and immediate prosthetic restoration. Patients treated with Rivaroxaban (Xarelto 20 mg daily) and who needed implant rehabilitation were selected. Four to six implants were placed in mandibular healed sites or fresh extraction sockets. All patients, in agreement with their physicians, interrupted the medication for 24 h and received implants and immediate restorations. Twelve patients and 57 implants were analyzed in the study. No major postoperative bleeding events were reported. Three patients (25%) presented slight immediate postoperative bleeding controlled with compression only. The implant and prosthetic survival rate were both 100% after 1 year. Within the limitations of this study, multiple implant placement with an immediate loading can be performed without any significant complication with a 24 h discontinuation of Rivaroxaban, in conjunction with the patient’s physician.

The New Method of Pocket Forming for Breast Implant Placement in Augmentation Mammaplasty: Dual Plane Subfascial

Introduction:

Breast augmentation is one of the most frequently performed aesthetic surgical procedures in the world. The most important preoperative decisions which influence the final appearance of the augmented breast are the breast implant pocket choice and selection of the most appropriate implant. Described pocket locations are subglandular, subfascial, partially retropectoral, totally submuscular and dual plane.

Aim:

We have introduced a new method of pocket forming for implant placement, which is combination of Tebbett’s dual-plane 2 or 3 and Graf’s subfascial. We named it as dual plane subfascial.

Methods:

Between January 2016 and April 2018, total of 27 patients were operated using dual plane subfascial breast augmentation. The pinch test in the medial pole less than 2,0 cm and in upper pole less than 2,5 cm are indications for this technique. In our modification, in primary cases a dissected flap in front of muscle is fasciocutaneous (not cutaneous as in Tebbett’s technique). It will be finally located caudally of pectoral muscle and in front of the lower pole of implant. Fasciocutaneous flap in primary cases and two independent levels of soft tissue coverage (fascial and cutaneous) in secondary cases (subglandular to dual plane subfascial conversion) in front of the lower pole of implants provide better coverage than cutaneous flap alone.

Results:

Hematoma and infection did not occur in any patient in our study. A capsular contracture grade I/II without the need for reoperation occurred in two patients. In one patient with secondary augmentation minimal bottoming out was noticed (before reoperation patient had significant bottoming out deformity). Minimal palpability of implants is recorded in three patients.

Conclusion:

Dual plane subfascial is a good option in primary breast augmentation with a well set indication especially in the breasts with the upper pinch test less than 25 mm and medial pinch test less than 20 mm. The idea can be followed even in secondary breast augmentation (subglandular to dual plane subfascial conversion). There is additional soft tissue in front of the implant which led to a less implant palpability, especially in thin patient with smaller amount of subcutaneous fat.

Antibiotic prophylaxis at dental implant placement: Which is the best protocol? A systematic review and network meta-analysis

AIM

This systematic review of randomized controlled trials (RCTs) aims to answer to the following question: "In patients undergoing dental implant placement, which is the best antibiotic prophylaxis protocol to prevent early failures?"

MATERIALS AND METHODS

The MEDLINE, SCOPUS, CENTRAL and Web of Knowledge electronic databases were searched in duplicate for RCTs up to July 2017. Additional relevant literature was identified through (i) handsearching on both relevant journals and reference lists, and (ii) searching in databases for grey literature. A network meta-analysis (NMA) was conducted, and the probability that each protocol is the "Best" was estimated.

RESULTS

Nine RCTs were included, with a total of 1,693 participants. Due to the few events reported, it was not possible to conduct a NMA for adverse events, therefore it was conducted only for implant failures (IF). The protocol with the highest probability (32.5%) of being the "Best" one to prevent IF was the single dose of 3 g of amoxicillin administered 1 hr pre-operatively. Even if the single pre-operative dose of 2 g of amoxicillin is the most used, it achieved only a probability of 0.2% to be the "Best" one.

CONCLUSIONS

Basing on the available RCTs, the use of antibiotic prophylaxis is protective against early implant failures. Whenever an antibiotic prophylaxis is needed, there is still insufficient evidence to confidently recommend a specific dosage. The use of post-operative courses does not seem however to be justified by the available literature. Prospero registration number: CRD42015029708.

Early and late implant failure of submerged versus non-submerged implant healing: A systematic review, meta-analysis and trial sequential analysis

INTRODUCTION

The aim of this systematic review was to analyse current evidence regarding differences in early and late implant failure as well as in marginal bone level (MBL) changes between submerged and non-submerged healed dental implants.

METHODS

PUBMED, SCOPUS, EMBASE and Web of Science databases were searched for prospective randomized and non-randomized controlled studies addressing direct comparison between submerged and non-submerged implant healing, without performing immediate loading. Early and late implant failure (before or after 6 months from implant placement, respectively) together with MBL were the investigated outcomes. Risk of bias assessment was performed using the Cochrane Collaboration Tool for Randomized clinical trials. Meta-analysis was performed and the power of the meta-analytic findings determined by trial sequential analysis (TSA).

RESULTS

Eleven studies met the inclusion criteria and were included in the review. Results of this systematic review revealed a small higher rate (2%) of early implant failure when a non-submerged healing approach is performed. Late implant failure appears not to be different in submerged or non-submerged healing, but the power of evidence, as determined by TSA, is not high. If we consider MBL changes at 1 year from implant load, it seems that non-submerged healing may better preserve marginal bone, although with a small effect size (0.13 mm).

CONCLUSIONS

Implants placed with a non-submerged technique have a higher risk (2%) of early failure. The power of the evidence about the effects on MBL is low, but present results seem to favour non-submerged healing, although with a very small effect size.

Group 2 ITI Consensus Report: Prosthodontics and implant dentistry

OBJECTIVES

Working Group 2 was convened to address topics relevant to prosthodontics and dental implants. Systematic reviews were developed according to focused questions addressing (a) the number of implants required to support fixed full-arch restorations, (b) the influence of intentionally tilted implants compared to axial positioned implants when supporting fixed dental prostheses (FDPs), (c) implant placement and loading protocols, (d) zirconia dental implants, (e) zirconia and metal ceramic implant supported single crowns and (f) zirconia and metal ceramic implant supported FDPs.

MATERIALS AND METHODS

Group 2 considered and discussed information gathered in six systematic reviews. Group participants discussed statements developed by the authors and developed consensus. The group developed and found consensus for clinical recommendations based on both the statements and the experience of the group. The consensus statements and clinical recommendations were presented to the plenary (gathering of all conference attendees) and discussed. Final versions were developed after consensus was reached.

RESULTS

A total of 27 consensus statements were developed from the systematic reviews. Additionally, the group developed 24 clinical recommendations based on the combined expertise of the participants and the developed consensus statements.

CONCLUSIONS

The literature supports the use of various implant numbers to support full-arch fixed prostheses. The use of intentionally tilted dental implants is indicated when appropriate conditions exist. Implant placement and loading protocols should be considered together when planning and treating patients. One-piece zirconia dental implants can be recommended when appropriate clinical conditions exist although two-piece zirconia implants should be used with caution as a result of insufficient data. Clinical performance of zirconia and metal ceramic single implant supported crowns is similar and each demonstrates significant, though different, complications. Zirconia ceramic FDPs are less reliable than metal ceramic. Implant supported monolithic zirconia prostheses may be a future option with more supporting evidence.

An overview of socket preservation

Socket preservation is a surgical procedure whose aim is to limit the physiological resorption of the alveolar ridge that occurs after a dental extraction, in order to have sufficient bone to perform an implant placement. 16 articles regarding socket preservation procedures were identified through scientific archives and analysed. The biological rationale, the graft materials and the predictive factors are identified to help the clinicians in their practice. Socket preservation is an effective treatment to prevent bone resorption if performed after an atraumatic extraction with the use of biomaterials and membranes. It is also important not to forget local and systemic predictive factors.

Optimized beagle model for maxillary sinus floor augmentation via a mini-lateral window with simultaneous implant placement

Objective

This study was performed to establish an optimized beagle model for maxillary sinus floor augmentation via a mini-lateral window with simultaneous implant placement.

Methods

Twelve beagles underwent maxillary sinus floor augmentation via a mini-lateral window with simultaneous implant placement through sites selected by analyzing preoperative cone beam computed tomography (CBCT) images. During the experiment, no maxillary teeth were extracted and the infraorbital nerve was not severed. The osteotomy was only 5 mm in diameter. The implant stability quotient was measured, and postoperative CBCT was used to detect the condition of the sinus membrane and bone augmentation.

Results

The site corresponding to the tip of the highest dental cusp of the maxillary fourth premolar was suitable for the procedure, and the implant site was on the palatal bone plate. All implants achieved good primary stability. Postoperative CBCT showed no sinus membrane perforation, and the implants penetrated into the sinus cavity surrounded by bone substitute.

Conclusion

The herein-described optimized model with mini-lateral osteotomy and without extraction or severing of the infraorbital nerve was minimally invasive, retained more lateral bone of the sinus, and achieved good sinus floor-lifting results. This model is highly reproducible and merits wider application.

Prevalence and measurement of anterior loop of the mandibular canal using CBCT: A cross sectional study

BACKGROUND

Anterior loop of the mental nerve is a very important anatomic landmark in implant placement and anterior mandibular osteotomies.

PURPOSE

Two-dimensional imaging techniques are not competent enough to locate and measure the mental nerve loop in majority of the cases. Any injury to this loop results in pain/paresthesia/numbness in the region supplied by the mental nerve. The aim of this study is to analyze the prevalence and measure the length of the loop using cone beam computerized tomography (CBCT) and calculate the average length and prevalence so that a safe margin can be given while placing the implants or the osteotomy cuts in the premolar region.

MATERIALS AND METHODS

A cross-sectional study was done using CBCT images of 85 patients taken for impaction surgery. The length of the loop was measured in mm using standardized lines drawn along specific anatomic landmarks.

RESULTS

In our study 11.76% of patients had anterior loop in their mental nerve. Mean length of the mental nerve loop was calculated and found to be 2.79 mm.

CONCLUSION

A margin of 4 mm anterior to the mental foramen should be safe to avoid any damage to the mental nerve loop bundle in majority of the cases where the loop is present.

Morphometric study of lingual foramina in macerated mandibles to assist in implant placement in the anterior mandibular region

The object of our study was to contribute to anatomical knowledge of this region with data on the prevalence, number and location of lingual foramina (LF) in dentate and edentate macerated mandibles from Brazilian individuals, differen-tiating them by sex and race. In this way we hope to help dental surgeons with their planning prior to implant placement in the anterior mandibular region. 103 macerated mandibles were analysed. The prevalence, number and location of LF were analysed in the median (MLF) and lateral (LLF) regions and the median (AMLF) and lateral (ALLF) alveolar process regions. Measurements for their location were taken with a digital calliper. 99% of the mandibles presented at least 1 MLF, 82.5% at least 1 LLF, and the frequency of ALLF was 67%. In dentate mandibles, MLF were located in the region superior to the genial spine, and in edentate mandibles in the regions superior and inferior to the genial spine. LLF were located in the middle region in both dentate and edentate mandibles. The height of the symphysis was significantly greater in dentate than in edentate cases. The distance from the alveolar crest (AC) to the MLF was significantly greater in dentate than in edentate mandibles. LF are constant structures, with MLF found more frequently than LLF. Mandibles which present a smaller measured distance from the base of mandible to AC present MFL and LLF closer to AC, implying a greater risk of complication during implant placement. (Folia Morphol 2018; 77, 2: 310-322).

Is there a consensus on antibiotic usage for dental implant placement in healthy patients?

This systematic review aimed to determine whether there is consensus for antibiotic prescription in healthy patients undergoing implant placement. A search of PubMed, Embase and Medline databases was conducted in January 2016 to find published journal articles on the use of antibiotics in implant placement, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The inclusion criteria were prospective human clinical trials investigating antibiotic usage during implant placement. Fifteen studies were deemed suitable. In 13 studies, no statistical difference was found between antibiotic use and the incidence of prosthetic failure, implant failure and early postoperative infections. These were rated as having low to high risk bias. Contrary results were reported in two studies, both of which were rated as having a high potential for bias. In conclusion, antibiotic use in healthy patients for the prophylaxis of surgical infection associated with dental implant placement does not appear to improve clinical outcomes. Practitioners should apply principles of antimicrobial stewardship and not use antibiotics as a routine measure in healthy patients.

Full arch rehabilitation in severe maxillary atrophy with palatal approach implant placement: a case report

PURPOSE

The edentulous severely atrophic maxilla, as consequence of alveolar bone resorption and pneumatisation of the maxillary sinus, represents a serious limitation to the implant rehabilitation. Implants insertion via palatal approach (PA), in combination with relatively minimally invasive techniques aimed at increasing bone volume without the use of autologous bone harvesting is a valid alternative among the options for the rehabilitation of the upper jaw.

CLINICAL CASE

In a 70-year-old female, with a severe maxillary atrophy, 6 spiral taper implants were placed with the PA, combined with the bilateral transcrestal elevation of both the sinus floors and nasal cavities; a further GBR, with resorbable pericardium membrane covering a termoplastic allograft associated to a xenograft, was performed. The second stage was performed after 6 months. Implant prosthetic functionalization was carried out in 4 months by placing the removable prosthesis in direct contact with the healing cup screws. After that period the case was finalized with a hybrid prosthesis. Clinical and radiographic follow-ups were carried out at 6 months and at one year after prosthetic finalization, during which no pathological signs were recorded.

CONCLUSIONS

The PA implant insertion described by the Authors, combined with bone augmentation procedures, performed in the same stage, may represent a valid and reliable solution to rehabilitate maxillary edentulous patients.

Neurophysiological changes associated with implant placement

OBJECTIVES

The objective of the study was to evaluate the feasibility of a standardized Quantitative Sensory Testing (QST) protocol extra- and intraoral in patients to detect and quantify sensory disturbances of the inferior alveolar nerve due to the proximity of implantation procedures to the inferior alveolar nerve canal.

MATERIAL AND METHODS

Patients who had obtained an implant placement were examined by implementing a comprehensive QST protocol for extra- and intraoral use. The study included 33 patients after implant placement in the lower jaw and one patient suffering from an inferior alveolar nerve injury. Patients were tested bilaterally (chin and mucosal lower lip).

RESULTS

Comparing the implanted vs. the control side, QST parameters revealed no significant neurophysiological changes in all parameters. Evaluating the development of sensory disturbances in dependency of the proximity of the implant to the inferior alveolar nerve canal, mechanical QST parameters showed no significant correlation. The mean distance of the inserted implant to the inferior nerve canal was 2.65 ± 1.75 mm. In the case of one patient suffering from impairment of the nerve function due to implant placement, we found abnormal sensory responses to touch coexisting with numbness and temperature algesia.

CONCLUSIONS

Monitoring of trigeminal nerve fiber functions by QST intra- and extraoral is feasible to evaluate oral sensory pattern after implantation procedures. Sensory disturbances of the inferior alveolar nerve were shown to be avoided by keeping an average safety zone of 2.65 mm between implant and nerve.

Interventions for replacing missing teeth: Antibiotics in dental implant placement to prevent complications: Evidence summary of Cochrane review

The failure of dental implant can occurs at the preoperative planning stage, at the surgical stage, and at the postoperative stage. The success of this treatment can be increased if the clinical implant practice guidelines are prepared based on the recommendations from the highest level of research evidence (i.e.,) from systematic review of randomized controlled trials (RCTs) with meta-analysis. The Cochrane reviews of interventions are basically systematic reviews of RCTs with meta-analysis but follow a systematic methodological approach following the guidelines from Cochrane handbook for Systematic Reviews of Intervention. They give the current best evidence as they are updated every 2 years which is being the minimum period for an update. This evidence summary recommends the use of antibiotics, single dose of 2 g of amoxicillin 1 h prior to implant surgery to prevent implant failure, based on the body of evidence from the Cochrane review that was first published in 2003, 2008, and then updated twice in 2010 and 2013. The included studies are not from our population for the research question asked in this updated Cochrane review; hence, the need to do primary research in our population to support the available evidence is mandatory.

Intervention for replacing missing teeth: Alveolar ridge preservation techniques for dental implant site development - evidence summary of Cochrane review

The Cochrane reviews have transparent reporting of the methodology to clarify the reader the methods used for writing the review; hence, each review becomes a large volume of scientific literature. This evidence summary of the Cochrane review published in 2015 for the question, what are the clinical effects (preservation of both width and height of bone, esthetic outcomes, complications, and failure of implant) for different alveolar ridge preservation techniques (ARP) and materials used in patients planning implant placement following extraction after 6 months follow-up. This review provides evidence for efficacy of different ARP techniques, materials, and superiority of one over the other. It also tries to settle the controversy of timing of placement of implant after grafting. Of the 8 included studies from 50, two trials provide moderate evidence for xenografts versus extraction favoring xenografts in preserving the width and height of bone by 1.97 mm (2.48-1.46) and 2.60 mm (3.43-1.76), respectively in pooled estimates of meta-analysis. Using different material, five-trial were found; of which, two trials provide moderate evidence for alloplast versus xenografts favoring alloplast in preserving the width by 0.44 mm (0.90-0.02) and low-grade evidence for height of bone by 0.35 mm (0.86-0.16) in pooled estimates of meta-analysis. There is a paucity of randomized controlled trial to address other primary and secondary outcomes addressed in this review.

Sandwich osteotomy of the atrophic posterior mandible prior to implant placement

Key Clinical Message The continuing resorption of the alveolar ridge will eventually result in insufficient bone height superior to the IAN, making dental implant placement impossible. The augmentation procedure above the IAN in terms of height provides sufficient bone for implant placement and allows long-term successful restoration of missing teeth with implant-supported prosthesis.

2-Dimensional changes of the soft tissue profile of augmented and non-augmented human extraction sockets: a randomized pilot study

AIM

This study identified the soft tissue changes of the alveolar ridge at different time points within 12 weeks after tooth extraction with and without socket augmentation.

MATERIALS AND METHODS

In 38 patients with single tooth extractions, 40 sockets were augmented and 39 extraction sockets were not augmented. At 2, 4, 6, 8 and 12 weeks impressions were taken and casts digitized with a laser scanner. The horizontal and vertical changes were compared between augmented and non-augmented sites. A p-value <0.05 was considered statistically significant.

RESULTS

The mean changes of augmented sockets were between 0.4 mm (2 weeks) and 0.8 mm (12 weeks). In non-augmented sockets changes of 0.7 mm (2 weeks) and of 1.0 mm (12 weeks) were demonstrated. The mean values differed significantly between the buccal and oral region (p < 0.01). Overall, there were significant differences of the mean dimensional changes regarding time (p < 0.01) and augmentation (p < 0.01).

CONCLUSIONS

Augmented sockets showed less resorption within 4 weeks after extraction compared to non-augmented sockets. Non-augmented sockets showed a continuous dimensional loss with a great variation over 12 weeks whereas augmented sockets had the highest degree of resorption between 4 and 6 weeks. At 12 weeks a comparable resorption in augmented and non-augmented sockets was observed.

Graftless sinus augmentation technique with contextual placement of implants: a case report

INTRODUCTION

The positioning of implants in the jaw bones with contextual graftless lateral approach sinus lifting is finding an increasingly broad consensus in the literature. Since the 1970s, various clinical research projects have been conducted on applications of biological and synthetic biomaterials in bone regenerative surgery, both in sinus lift procedures and in cystic cavity filling after cystectomy or in bone defects in regenerative periodontal surgery. Currently, we are finding that there is an increasing trend of clinicians aiming to adopt graftless techniques, with satisfactory results in terms of implant survival in the long term. In our study, through a case report, we describe a variant of graftless sinus augmentation technique with contextual implant placement, emphasizing the role of the blood clot, combined with collagen sponges, as a natural scaffold and the osteogenic potential of the subantral membrane in guided bone regeneration, with reduced morbidity of the patient.

CASE PRESENTATION

To describe the surgical technique, the clinical case of a 38-year-old Caucasian woman with a lateral posterior edentulism was selected. The rehabilitation was solved by a graftless sinus augmentation technique with a contextual implant placement. For each implant, a resonance frequency analysis evaluation was reported as implant stability quotient values. The performance of the implant stability quotient values followed a gradual increase from time zero to the sixth month, as the clot was differentiated into osteoid tissue and then into bone tissue, due to the scaffold effect conferred by the equine collagen sponge. The stabilization phase took place between the fourth and the sixth month, according to the implant stability quotient values.

CONCLUSIONS

Our graftless sinus augmentation technique seems to be very predictable thanks to the osteoconductive principles on which it is based, and in association with the proper management of peri-implant soft tissue, so as to increase the amount of keratinized tissue, which could represent the new gold standard for this type of rehabilitation in the future.

Safe approach in "All-on-four" technique: a case report

The "All-on-Four" concept is based on the placement of four implants in the anterior part of fully edentulous jaws to support a provisional, fixed, and immediately loaded full-arch prosthesis. Combining tilted and straight implants for supporting fixed prostheses can be considered a viable treatment modality resulting in a more simple and less time consuming procedure, in significantly less morbidity, in decreased financial costs and a more comfortable postsurgical period for the patients. The authors present a case report with mandibular atrophy and left mental foramina on the top of the residual crest.

Implant-based oral rehabilitation of a variant model of type I dentinal dysplasia: A rare case report

Dentin dysplasia is an exceptionally rare, autosomal-dominant, hereditary condition, primarily characterized by defective dentin formation affecting both the deciduous and permanent dentitions. The etiology remains imprecise to date, in spite of the numerous hypotheses put forward and the constant updates on this condition. This case report of type I dentin dysplasia exhibits radiographic findings that are unique and diverse from the classical findings of various subtypes of this disease reported to date. This article also depicts the implant-based oral rehabilitation of the young patient diagnosed with this variant model of dentin dysplasia type I. Early diagnosis and implementation of this preventive and curative therapy is vital for avoiding premature exfoliation of deciduous and permanent dentition and the associated residual ridge resorption, thereby overcoming functional and esthetic deficits and ensuring protection of the remaining dentition from further harm.

Is furcation involvement in maxillary molars a predictor for subsequent bone augmentation prior to implant placement? A pilot study

AIM

The aim of this pilot study was to analyze the interfurcal bone height in relation to the possible need for subsequent sinus floor elevation in patients with advanced periodontitis and furcation involvement of first and/or second maxillary molars.

MATERIAL AND METHODS

Seventeen dentate patients, who received cone beam computed tomography (CBCT) for detailed preoperative diagnosis and planning of surgical interventions at periodontally involved maxillary molars (17 first and 15 second molars), were consecutively recruited for the study. The minimal bone height in the interfurcal region was measured from CBCT and related to furcation involvement, residual bone above the root tips, and the clinical probing pocket depth (PPD).

RESULTS

The minimal interfurcal bone height measured 4.1 ± 2.6 mm on average with 75% of maxillary molars having ≤ 6 mm and almost 60% having only ≤ 4 mm bone height left below the sinus floor. A higher risk for reduced interfurcal bone height of ≤ 4 mm was given when residual PPD of ≥ 6 mm was remaining at two or more tooth sites (OR 0.10; 0.11).

CONCLUSIONS

The majority of periodontally involved maxillary molars had a substantially reduced interfurcal bone height, particularly with at least two sites with residual PPD ≥ 6 mm. This was a predictor for a subsequent need for sinus floor elevation when tooth replacement with a dental implant is desired.

A clinically relevant accuracy study of computer-planned implant placement in the edentulous maxilla using mucosa-supported surgical templates

PURPOSE

The purpose of the study is to determine the clinically relevant accuracy of implant placement in the edentulous maxilla using computer planning and a mucosa-supported surgical template.

MATERIALS AND METHODS

In each of in total 30 consecutive edentulous patients suffering from retention problems of their upper denture, two or four Brånemark MkIII Groovy (Nobel Biocare®, Zürich, Switzerland) implants in the maxilla were installed. Preoperatively, first, a cone-beam computer tomography (cone beam computer tomography) scan was acquired, followed by virtual implant planning. Hereafter, a surgical template was designed to allow flapless implant placement using the template as a guide. To inventory the accuracy of implant placement, a postoperative CBCT scan was obtained and matched to the preoperative scan. The accuracy of implant placement was validated three-dimensionally. The Implant Position Orthogonal Projection validation method was applied to measure the clinically relevant implant deviations (i.e., in both the bucco-lingual and mesio-distal plane). Also, the influence of type of surgery, use of fixation pins, and position on the dental arch were investigated with regard to implant deviations.

RESULTS

In total, 104 implants were installed. In bucco-lingual direction, a mean implant deviation of 0.67 mm was scored at the implant tip, of 0.51 mm at the shoulder, of -0.83 mm in depth, as also a mean deviation of angulation of 1.74°. In mesio-distal direction, a mean implant deviation of 0.75 mm was found at the implant tip, of 0.60 mm at the implant shoulder, of -0.75 mm in depth, and a deviation of angulation of 1.94°. Of all implants, 74% was placed not deep enough compared with the planning. Implant position on the dental arch, the use of fixation pins, and type of surgery showed no significant effect on implant deviations. However, a significant difference for implant deviations in both buccal and mesial direction was observed, explained by a nonoptimal positioning of the surgical template.

CONCLUSIONS

Computer-aided implant planning showed to be a clinically relevant tool for the placement of two or four implants in the maxilla of fully edentulous patients. Exact positioning of the surgical template in anterior/posterior direction is crucial in reducing implant deviations both in buccal and mesial direction.

Real-time thermographic analysis of low-density bone during implant placement: a randomized parallel-group clinical study comparing lateral condensation with bone drilling surgical technique

OBJECTIVES

To compare the effect of two surgical techniques, lateral condensation and bone drilling, on changes in temperature of the adjacent low-density bone during implant placement into posterior maxilla and to investigate the influence of the host factors - age, gender, region of implantation, bone density, and thickness of the cortical bone at the recipient sites.

MATERIAL AND METHODS

Local bone temperature was measured thermographically during implant placement into posterior maxilla following lateral bone condensing (test group) or bone drilling (controls). The main study outcomes were baseline bone temperature prior to implantation and maximum bone temperature recorded during implantation. Early implant success was evaluated after 6 months of healing.

RESULTS

A total of 40 implants were randomly allocated to test and control groups and placed into maxillary premolar and/or molar region of 18 participants of both genders and average age of 51.74 years. All recorded bone temperatures were below the threshold for thermal necrosis. Although both groups showed significant increase in bone temperature during implant placement procedure (P ≤ 0.0005), it was significantly higher for bone condensing compared with drilling (P ≤ 0.0005; 3.79 ± 1.54°C; 1.91 ± 0.70°C respectively). No host factor was singled out as a significant predictor of bone temperature changes, although trend of higher increase was observed in young patients, regardless of gender, during implant placement procedure into maxillary first premolar region with bone density type 3 and cortical layer thicker than 1 mm. Early implant success rate after 6 months follow-up was 100%.

CONCLUSION

Although both surgical techniques, bone condensing and bone drilling, can be considered safe regarding their thermal effect on the bone of posterior maxilla, bone drilling is associated with fewer local bone heating during implantation. Host factors do not affect the bone thermal changes significantly.

Successful dental implant placement surgeries with buccal bone fenestrations

This is the first comprehensive review of the classification, preventative measures, diagnosis, treatment methods, and determination of success criteria of buccal bone plate fenestrations (BPFs) secondary to posterior implant surgeries. The purpose of this review is to present and discuss the current literature from peer-reviewed journals, recent studies, and international implantology guidelines and to provide practitioners with guiding points to identify and understand whether BPFs are complications or accidents of implant surgeries. In addition, this review sets forth a detailed set of criteria for the evaluation and diagnosis of BPFs and for the subsequent classification of BPFs as either complications or accidents of posterior implant surgeries. From the literature analyzed, it is clear that BPFs are disqualified from the class of implant treatment failures because BPFs neither impair nor significantly delay treatment. A comprehensive outline of preventative measures and surgery aids to avoid fenestrating the buccal bone plate during implant placement, and a variety of repair methods are included in this review. Considerations of treatment outcomes and patient sensitivities are also included in this comprehensive review.

A clinically relevant validation method for implant placement after virtual planning

PURPOSE

To design a relevant method to compare the virtual planned implant position to the ultimately achieved implant position and to evaluate, in case of discrepancy, the cause for this.

MATERIALS AND METHODS

Five consecutive edentulous patients with retention problems of the upper denture received four implants in the maxilla. Preoperatively, first a cone-beam CT (CBCT) scan was acquired, followed by virtual implant planning. Then, a surgical template was designed and endosseous implants were flapless installed using the template as a guide. To inventory any differences in position, the postoperative CBCT scan was matched to the preoperative scan. The accuracy of implant placement was validated three-dimensionally (3D) and the Implant Position Orthogonal Projection (IPOP) validation method was applied to project the results to a bucco-lingual and mesio-distal plane. Subsequently, errors introduced by virtual planning, surgical instruments, and validation process were evaluated.

RESULTS

The bucco-lingual deviations were less obvious than mesio-distal deviations. A maximum linear tip deviation of 2.84 mm, shoulder deviation of 2.42 mm, and angular deviation of 3.41° were calculated in mesio-distal direction. Deviations included errors in planning software (maximum 0.15 mm), for surgical procedure (maximum 2.94°), and validation process (maximum 0.10 mm).

CONCLUSIONS

This study provides the IPOP validation method as an accurate method to evaluate implant positions and to elucidate inaccuracies in virtual implant planning systems.

Stereoscopic technique for conversion of radiographic guide into implant surgical guide

PURPOSE

The aim of this study was to develop and evaluate a new stereoscopic technique for conversion of radiographic guide into surgical guide for dental implant placement.

MATERIALS AND METHODS

Ten partially dentate patients requiring 18 implants for tooth replacement were recruited. Radiographic guides were modified with the addition of index rods for double computed tomography scanning. Implant positions were planned with implant planning software, and the stereoscopic angulations were measured. The radiographic guides were converted into surgical guides using either a generic bench drill (Group A, n = 9) or a milling machine (Group B, n = 9). Stereolithographic surgical guides were also made for three patients (Group S, n = 5). Differences between the planned and actual angulations were tested by pair-sample t-test. Difference of mean angle deviation among groups was tested by Brown-Forsythe test. Differences were considered significant if p < .05.

RESULTS

Eighteen implant sites were successfully treated with the converted surgical guides. The mean angle deviation of Group A (1.3 ± 0.6°) was significantly greater than Group S (0.4 ± 0.6°), while no differences were found between Group B (0.9 ± 0.3°) and Group S. The linear error was greatest in Group A with 1.5 mm at the head and 1.8 mm at the apex of the implant.

CONCLUSIONS

The use of this new stereoscopic technique appears to be an acceptable alternative method for converting radiographic guide into surgical guide.