Accuracy of open-sleeved vs. closed-sleeved static computer-assisted implant systems in immediate maxillary molar implant placement: An in vitro study.

OBJECTIVES: The objective of this study is (1) to compare the accuracy of an open-sleeved static computer-assisted implant system (sCAIS) with a closed-sleeve sCAIS and free-hand approach in immediate implant placement (IIP) of maxillary molar sites and (2) to investigate the influence of socket morphology on these approaches. MATERIALS AND METHODS: Ninety partially edentulous duplicated maxillary models simulating three different molar sockets (type A, B, and C based on Smith and Tarnow's classification) were investigated. Three modalities, including sCAIS with open-sleeves, sCAIS with closed-sleeves, and free-hand approach, were applied separately to 30 models with 120 sockets. A customized Python script automatically measured the deviations between the virtual and actual implant positions for all 360 implants. RESULTS: The 3D deviations of sCAIS were significantly influenced by the socket and sleeve types. Both guided groups exhibited significantly less deviation than the free-hand approach. Type A and C sockets resulted in better implant positions than type B socket sites. In type B sockets, the open-sleeve group achieved significantly less deviation compared to the closed-sleeve group, with respect to apical global (1.34 ± 0.53 vs. 1.84 ± 0.59 mm), coronal horizontal (0.68 ± 0.36 vs. 0.93 ± 0.34 mm), apical horizontal (1.21 ± 0.59 vs. 1.74 ± 0.63 mm), and angular (3.30 ± 1.41 vs. 4.41 ± 1.96°) deviations. CONCLUSIONS: Guided implant surgery significantly reduces deviations during molar IIP compared to free-hand procedures. Furthermore, the use of open-sleeve sCAIS appears to be more effective in minimizing deviations in type B sockets when compared with the closed-sleeve guided system.

Recommendations for successful virtual patient-assisted esthetic implant rehabilitation: A guide for optimal function and clinical efficiency.

OBJECTIVE: Complete arch implant rehabilitation necessitates meticulous treatment planning and high-level collaboration between surgical and prosthetic dental teams. Emerging virtual technologies hold considerable promise in streamlining this process. The aim of this article is to extend recommendations to clinicians venturing into the virtual patient-assisted esthetic implant rehabilitation workflow. OVERVIEW: This article summarizes recommendations for virtual patient-assisted esthetic implant rehabilitation in the following five aspects: three-dimensional data handling and superimposition, occlusion and virtual articulator integration in creating virtual patients, streamlined face- and prosthetic-driven surgical planning, reuse of presurgical data ("Copy & Paste"), and final impression for passive fitting of final restoration. To illustrate these principles, a case with complete-mouth implant rehabilitation completed within six visits using this virtual patient workflow is presented. CONCLUSION: The virtual patient workflow serves as an invaluable tool to perform treatment planning, enhance efficiency, and ensure predictable outcomes in esthetic complete arch implant rehabilitation. CLINICAL SIGNIFICANCE: Virtual workflows are increasingly prevalent in esthetic implant rehabilitation. Nevertheless, these workflows necessitate a distinct set of knowledge and tools divergent from conventional dentistry practices. This article offers guidelines and recommendations for dental clinicians who are new to this field.

Soft tissue phenotype modification impacts on peri-implant stability: a comparative cohort study.

OBJECTIVES: Soft tissue phenotype modification (STPM) could be performed to maintain peri-implant health. Therefore, the aim of the study was to analyze tissue alteration around implants following soft tissue phenotype modification during implant uncovering surgery. MATERIALS AND METHODS: Patients who had STPM (either pouch roll or modified roll technique) during implant second-stage surgery with at least 12-month follow-up were included. Clinical and radiographic parameters including mucosal tissue thickness (MTT), recession (REC), keratinized mucosa width (KMW), probing pocket depth (PPD), marginal bone loss (MBL), emergence profile, and emergence angle were extracted from 2-week, 2-month, and 12-month visits after second-stage surgery. RESULTS: Twenty-eight patients with 33 implants that fulfilled the inclusion criteria were included. After soft tissue phenotype modification, at 2 weeks, REC was negatively correlated to mean MTT at mid-buccal site (r = - 0.41, p = 0.018) and borderline correlated at mid-lingual site (r = - 0.343, p = 0.051). Stable KMW was maintained from 2 weeks to 12 months with minimal shrinkage rate (3 ~ 14%). MBL change was limited (0.24 ~ 0.47 mm) after STPM. All implants had shallow PPD (≤ 3 mm) with the absence of bleeding on probing. Emergence angle at the mesial side, however, was significantly correlated to surgical techniques, which indicated pouch roll technique would have 6.96 degrees more than modified roll technique (p = 0.024). CONCLUSIONS: Soft tissue phenotype modification, either pouch roll or modified roll technique, during uncovering surgery resulted in favorable clinical outcomes. Thin mucosal tissue thickness and pouch roll technique are the factors related to more recession at 2 weeks. Pouch roll technique could influence the restorative design by having a wide emergence angle at the mesial side. CLINICAL RELEVANCE: Modified and pouch roll techniques during uncovering surgery were viable methods to yield favorable peri-implant health, while the preciseness of pouch roll technique was required to avoid mucosal recession and inadequate restorative design.

Prosthetic articulator-based implant rehabilitation virtual patient: A technique bridging implant surgery and reconstructive dentistry.

This technique report describes a fully digital workflow to create a prosthetic articulator-based implant rehabilitation (PAIR) virtual patient for complete-arch or complete-mouth implant rehabilitation. This workflow uses a custom gothic arch tracer during the cone beam computed tomography (CBCT) scan and a 3-dimensional virtual facebow when superimposing data. The PAIR virtual patient possesses reliable centric relation and vertical dimension of occlusion and is compatible with virtual articulators. Computer-aided implant planning and a digital prosthetic design can be seamlessly integrated by using this virtual patient.

Open-sleeve templates for computer-assisted implant surgery at healed or extraction sockets: An in vitro comparison to closed-sleeve guided system and free-hand approach.

OBJECTIVE: A buccal opening guide provides better view and better irrigation. The aim of this study was to investigate the accuracy of this open-sleeve system. MATERIAL AND METHODS: Thirty duplicated maxillary models, each with six extraction sockets and four healed sites, were used. Based on the same digital plan, three modalities, sCAIS with open-sleeves, closed-sleeves, and free-hand approach, were used to place implants. The global, horizontal, depth, and angular deviations between the virtual and actual implant positions were measured. RESULTS: Both sCAIS groups exhibited better accuracy than the free-hand group in two clinical scenarios. At healed sites, the closed-sleeve group showed a significantly fewer error than the open-sleeve group in global apical (0.68 ± 0.33 vs. 0.96 ± 0.49 mm), horizontal coronal (0.28 ± 0.15 vs. 0.44 ± 0.25 mm), horizontal apical (0.64 ± 0.32 vs. 0.94 ± 0.48 mm), and angular deviations (1.83 ± 0.95 vs. 2.86 ± 1.46°). For extraction sockets, the open-sleeve group exhibited fewer deviations than the closed-sleeve group in terms of global (coronal: 0.77 ± 0.29 vs. 0.91 ± 0.22 mm; apical: 1.08 ± 0.49 vs. 1.37 ± 0.52 mm) and horizontal (coronal: 0.60 ± 0.24 vs. 0.86 ± 0.20 mm; apical: 0.95 ± 0.50 vs. 1.32 ± 0.51 mm) deviations. However, the closed-sleeve group was more accurate in the depth control (0.26 ± 0.20 vs. 0.40 ± 0.31 mm). CONCLUSION: In this in vitro investigation, open-sleeve sCAIS proved better accuracy than free-hand surgery for both delayed and immediate implant placement. Compared with a closed-sleeve sCAIS system, open sleeve have the potential of providing better outcomes in extraction sockets but not in healed sites.

Improvement in Osseointegration of Titanium Dental Implants After Exposure to Ultraviolet-C Light for Varied Durations: An Experimental Study in Beagle Dogs.

PURPOSE: Ultraviolet-mediated photofunctionalization is a valid technology for enhancing the osseointegration of titanium implants. However, there is no consensus on the effective exposure time to ultraviolet light. The objective of this study was to evaluate the effect of different exposure times of ultraviolet-C (UVC) light on aged titanium implants and explore the optimal treatment duration of UVC photofunctionalization for osseointegration in an animal model. METHODS: Eight male beagle dogs (n = 48) were divided into a control group (n = 12) and 3 experimental groups (n = 12/12/12) which received 4-week-old implants without UVC treatment (C) or treated with UVC for 1/6 hour, 1/2 hour, and 1 hour (UVC-1/6 hour, UVC-1/2 hour, UVC-1 hour) immediately before placement. All the implants were placed 12 weeks after mandibular premolars extraction. Four dogs were euthanized after 4 and 12 weeks of healing, respectively. The marginal bone level and implant stability quotient were measured at implant placement and after sacrifice. Subsequently, micro-CT and histomorphometric analyses were performed following block harvesting. RESULTS: No significant difference in marginal bone loss between the UVC-untreated and UVC-treated groups was found at 4 or 12 weeks. At 4 weeks, significantly higher BV/TV and bone-implant contact were observed in the UVC groups than in the C group, irrespective of the UVC-photofunctionalization duration (BV/TV: UVC-1/6 hour 0.48 ± 0.11, UVC-1/2 hour 0.50 ± 0.06, and UVC-1 hour 0.47 ± 0.08, C 0.34 ± 0.04; bone-implant contact : UVC-1/6 hour 84.30 ± 5.02%, UVC-1/2 hour 85.82 ± 5.05%, and UVC-1 hour 84.98 ± 3.86%, C 71.69 ± 3.52%. P < .05), whereas, no significant difference was observed among the UVC groups. At 12 weeks, there were no significant differences between the C group and UVC groups. After 4 and 12 weeks of healing, no significant difference in implant stability quotient values was observed between the C group and UVC groups. CONCLUSIONS: UVC photofunctionalization improved the early osseointegration of aged titanium implants. However, the effect was not dependent on the UVC-light duration within the range from 1/6 hour to 1 hour.

Does guided level (fully or partially) influence implant placement accuracy at post-extraction sockets and healed sites? An in vitro study.

OBJECTIVES: The aim of this study is to evaluate the effect of guide level on the accuracy of static computer-aided implant surgery (sCAIS) at post-extraction sockets and healed sites. MATERIALS AND METHODS: A total of 30 duplicate dental models, with 300 potential implant sites, were used. All the models were equally randomized into three groups: fully guided (FG, n = 100), partially guided (PG, n = 100), and free handed (FH, n = 100) surgeries. After implant placement, the mean global, horizontal, depth, and angular deviations between the virtually planned and actual implant positions were measured automatically by a Python script within software Blender. RESULTS: Both FG and PG surgeries showed significantly higher accuracy than FH surgery at post-extraction sockets and healed sites. In both sCAIS groups, there were nearly 50% more deviations from implants placed at sockets than those from delayed placement. For the immediate implant placement, the accuracy of sCAIS was significantly affected by the level of guidance. The FG group exhibited lower deviations than the PG group, with a significant difference in coronal global and horizontal deviations (p < .05). For the healed sites, two guided groups exhibited similar outcomes (p > .05). CONCLUSIONS: sCAISs provide more accuracy than the free-handed approach in position transferring from planning to a model simulation. Full guidance can significantly increase the accuracy, especially at post-extraction sites. CLINICAL RELEVANCE: Guided protocols showed significantly higher accuracy than free-handed surgery regardless of implantation timing, but both had nearly 50% more deviations in immediate implant placement.

Trueness and Precision of Economical Smartphone-Based Virtual Facebow Records.

PURPOSE: To investigate the trueness and precision of virtual facebow records using a smartphone as a three-dimensional (3D) face scanner. MATERIAL AND METHODS: Twenty repeated virtual facebow records were performed on two subjects using a smartphone as a 3D face scanner. For each subject, a virtual facebow was attached to his/her maxillary arch, and face scans were performed using a smartphone with a 3D scan application. The subject's maxillary arch intraoral scan was aligned to the face scan by the virtual facebow fork. This procedure was repeated 10 times for each subject. To investigate if the maxillary scan is located at the right position to the face, these virtual facebow records were superimposed to a cone-beam computed tomography (CBCT) head scan from the same subject by matching the face scan to the 3D face reconstruction from CBCT images. The location of maxillary arch in virtual facebow records was compared with its position in CBCT. The "trueness" of the proposed procedure is defined as the deviation between maxilla arch position in virtual facebow records and the CBCT images. The "precision" is defined as the deviation between each virtual facebow record. The linear deviation at left central incisor (#9), left first molar (#14), and right first molar (#3), as well as angular deviation of occlusal plane were analyzed with descriptive statistics. Differences between two objects were also explored with Mann Whitney U test. RESULTS: The 20 virtual facebow records using the smartphone 3D scanner deviated from the CBCT measurements (trueness) by 1.14 ± 0.40 mm at #9, 1.20 ± 0.50 mm at #14, 1.12 ± 0.51 mm at the #3, and 1.48 ± 0.56° in the occlusal plane. The VFTs deviated from each other by 1.06 ± 0.50 mm at #9, 1.09 ± 0.49 mm at #14, 1.11 ± 0.58 mm at #3, and 0.81 ± 0.58° in the occlusal plane. When all sites combined, the trueness was 1.14 ± 0.40 mm, and the precision was 1.08 ± 0.52 mm. Out of eight measurements, three measurements were significantly different between subjects. Nevertheless, the mean difference was small. CONCLUSIONS: Virtual facebow records made using smartphone-based face scan can capture the maxilla position with high trueness and precision. The deviation can be anticipated as around 1 mm in linear distance and 1° in angulation.

Intraoral scanning reduces procedure time and improves patient comfort in fixed prosthodontics and implant dentistry: a systematic review.

OBJECTIVES: The primary aim of this systematic review was to evaluate whether intraoral scanning (IOS) is able to reduce working time and improve patient-reported outcome measures (PROMs) compared to conventional impression (CI) techniques, taking into account the size of the scanned area. The secondary aim was to verify the effectiveness of IOS procedures based on available prosthodontic outcomes. MATERIALS AND METHODS: Electronic and manual literature searches were performed to collect evidence concerning the outcomes of IOS and CI performed during the treatment of partially and complete edentulous patients for tooth- or implant-supported restorations. Qualitative analysis was conducted to evaluate the time efficiency and PROMs produced by the two different techniques. Clinical prosthodontic outcomes were analyzed among the included studies when available. RESULTS: Seventeen studies (9 randomized controlled trials and 8 prospective clinical studies) were selected for qualitative synthesis. The 17 included studies provided data from 430 IOS and 370 CI performed in 437 patients. A total of 7 different IOS systems and their various updated versions were used for digital impressions. The results demonstrated that IOS was overall faster than CI independent of whether quadrant or complete-arch scanning was utilized, regardless of the nature of the restoration (tooth or implant supported). IOS was generally preferred over CI regardless of the size of the scanned area and nature of the restoration (tooth- or implant-supported). Similar prosthodontic outcomes were reported for workflows implementing CI and IOS. CONCLUSIONS: Within the limitations of this systematic review, IOS is faster than CI, independent of whether a quadrant or complete arch scan is conducted. IOS can improve the patient experience measured by overall preference and comfort and is able to provide reliable prosthodontic outcomes. CLINICAL RELEVANCE: Reduced procedure working time associated with the use of IOS can improve clinical efficiency and the patient experience during impression procedures. Patient-reported outcome measures (PROMs) are an essential component of evidence-based dental practice as they allow the evaluation of therapeutic modalities from the perspective of the patient. IOS is generally preferred by patients over conventional impressions.

Potential of Using an Implant Fixture as a Ridge Expander for Minor Ridge Augmentation: An Ex Vivo Randomized Controlled Study.

To place implants with minimal trauma is what the patient and clinician are seeking. Hence, the aim of this study was to quantify the potential of using an implant fixture as a ridge expander in an underprepared osteotomy. Thirty-eight edentulous sites in 12 human cadaver jaws with ridge widths ranging from 4 to 6 mm and with type 3 or type 4 bone density were randomly assigned into 2 groups. In the ridge expansion group (RE), each osteotomy was drilled to a width of 2.8 mm and depth of 11.5 mm. In the non-ridge expansion (NE) control group, each osteotomy was drilled to a width of to 3.4 mm and depth of 11.5 mm. A 3.7 mm × 11.5 mm tapered implant was inserted into each site. The ridge width before (RW1) and after (RW2) implant placement as well as the buccal plate thickness (BPT) post-insertion were measured and analyzed. In the RE group, the average RW1 and RW2 were 4.69 ± 0.45 mm and 5.54 ± 0.35 mm, respectively, corresponding to a statistically significant ridge expansion of 0.85 mm (P < .01). In the NE group, no ridge width gain was observed (RW1: 4.79 ± 0.40 mm, RW2: 4.88 ± 0.42 mm). Compared to NE, RE resulted in a statistically greater BPT (1.08 ± 0.28 mm after RE vs 0.71 ± 0.37 mm after NE, P < .001). Our study determined that it was physically possible to widen a ridge by an average of 0.85 mm by osteotomy underprepation in ridge with type 3 or type 4 bone density, which effectively turned the implant upon insertion into a ridge expander. The physiological consequences of this method of ridge expansion in a living person must be established before drawing further conclusions about its clinical indications or efficacy.

Capnography monitoring in procedural intravenous sedation: a systematic review and meta-analysis.

OBJECTIVES: Currently, procedural sedation in the clinical setting relies heavily on the use of pulse oximetry to monitor hypoxemia. Different studies suggest that incidence of hypoxemia and incidence of arterial oxygen desaturation are reduced by early intervention via capnography monitoring. The aim of this article was to discuss the importance of implementing capnography monitoring during procedural sedations performed in a dental setting and determine whether additional capnographic monitoring reduces the incidence of arterial oxygen desaturation and the overall complications rate. MATERIALS AND METHODS: Two independent reviewers conducted electronic (PubMed and EMBASE) and manual searches up to February 2020. Randomized clinical trials (RCTs), including both patients under procedural sedation monitored by capnography and oximetry, and reporting the incidence of hypoxemia or episodes of oxygen desaturation were included. Risk ratio was used to compare the outcomes (i.e., the incidence of hypoxemia, the episodes of oxygen desaturation, the detection of apnea, the reduction of events of bradycardia, and hypotension) between patients monitored by capnography and standard approach. RESULTS: Fourteen randomized clinical trials fulfilling the inclusion criteria were selected. The analysis revealed that capnography monitoring group showed the lower incidence of hypoxemia (RR 0.76, 95%CI 0.70 to 0.83, p < 0.001) and the episodes of oxygen desaturation (RR 0.79, 95%CI 0.71 to 0.87, p < 0.001) compared with the oximetry monitoring group. Apnea was detected in capnography monitoring earlier than standard monitoring (RR 2.60, 95%CI 2.30 to 2.93, p < 0.001). No significant difference was found between capnography and standard monitoring groups in terms of reduction of events of bradycardia (RR 1.17, 95%CI 0.91 to 1.50, p = 0.225) and hypotension (RR 0.96, 95%CI 0.76 to 1.21, p = 0.746). CONCLUSION: Capnography monitoring reduced incidence of hypoxemia during procedural sedations. Within the limitations of this review, we suggest that the application of capnography during procedural sedation would decrease the frequency of oxygen desaturation events and incidence of hypoxemia. CLINICAL RELEVANCE: Training and instructing dental providers on using capnography monitoring would help in reducing adverse events during intravenous sedation.

A digital workflow with computer-assisted implant planning for fabricating an impression splinting framework and custom tray for multiple implants.

A fully digital workflow for designing and manufacturing a splinted framework and a custom tray for the impression of multiple implants placed with guided surgery is described. This digital workflow protocol does not require extra visits after surgery to prepare for the definitive impression because of the use of preoperative digital implant planning data. As a result, it helps reduce laboratory procedures, chairside time, and treatment cost.

Registering Maxillomandibular Relation to Create a Virtual Patient Integrated with a Virtual Articulator for Complex Implant Rehabilitation: A Clinical Report.

The virtual patient, a unique computer simulation of the patient's face, teeth, oral mucosa, and bone, provides an extraordinary mechanism for digital dental implant surgery planning and prosthetic design. However, the seamless registration of digital scans with functional information in the context of a virtual articulator remains a challenge. This report describes the treatment of a 47-year-old male with full-mouth guided immediate implant placement and immediate loading of CAD/CAM interim prostheses. Utilizing a novel digital workflow, a multifactorial registration of the vertical dimension of occlusion, centric occlusion, and facebow record were completed digitally and paired within a digital articulator. Utilizing this innovative approach, a complex treatment plan and procedure was executed smoothly with a successful prosthetic outcome demonstrating good fit, occlusion, esthetics, and patient reported satisfaction.

The effect of supportive care in preventing peri-implant diseases and implant loss: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the influence of supportive treatment (SPT) during a maintenance period after implant placement on implant survival rate (SR) and incidence of peri-implant diseases. MATERIAL AND METHODS: A systemic literature search for studies published up to June 2018 was conducted by two independent reviewers using Pubmed/MEDLINE, EMBASE, and Cochrane Central databases. Clinical controlled trials (CCT) involved in SPT protocol with more than 1-year follow-up were included. Quantitative meta-analyses were carried out to analyze the risk ratio (RR) of SR, the incidence of peri-implantitis, and peri-implant mucositis between SPT and non-SPT groups. Any potential confounding factors were investigated using meta-regression. RESULTS: Nine CCTs fulfilled the criteria. To evaluate the influence of SPT on SR, peri-implantitis, and peri-implant mucositis, six of nine, three of nine, and three of nine articles were included in further meta-analysis, respectively. SPT group significantly showed higher SR (RR: 1.10; p < 0.001), lower prevalence of peri-implantitis (RR: 0.25; p < 0.001) and peri-implant mucositis (RR: 0.57; p < 0.001) than the non-SPT group. Meta-regression of the selected studies failed to find an association between SR, peri-implantitis, and peri-implant mucositis and confounding factors: application of chemical agents and the frequency of SPT. CONCLUSION: SPT can potentially improve peri-implant health in terms of SR, peri-implantitis, and peri-implant mucositis. Additionally, the correlation in recall interval and adjunctive use of chemical agents during SPT to peri-implant diseases and implant loss could not be found.

Dynamic changes of peri-implant soft tissue after interim restoration removal during a digital intraoral scan.

STATEMENT OF PROBLEM: During a digital intraoral scan for an esthetic implant restoration, the peri-implant soft tissue will collapse rapidly after the interim restoration (IR) is removed, making it difficult to replicate the established emergence profile. The rate of this collapse is unclear. PURPOSE: The purpose of this clinical study was to determine whether significant dimension differences could be found between peri-implant soft tissue supported by an IR and that immediately after removal of the restoration and to assess the changes over time. MATERIAL AND METHODS: Optical scans were made of 12 single implant sites in the esthetic zone of 10 participants. The scans in the first group replicated the peri-implant soft tissue contour with the support of the IR; in the second group, scans were made at different times from 0 seconds to 20 minutes after removal of the restoration. The changes in the soft tissue contour, including the height of the mesial papilla, distal papilla, and gingival margin, the facial and palatal soft tissue thickness, and emergence profile discrepancies (EPDs), were assessed. A linear mixed model was built to estimate the EPD. RESULTS: After the removal of IR, the palatal soft tissue thickness increased over time, and only minimal changes were found in the height of the mesial papilla, distal papilla, and gingival margin (up to -0.27 mm at 20 minutes). A significant EPD was immediately present at all the measurement sites after the removal of the IR. The linear mixed model showed a significant positive correlation between the natural logarithm of time and EPD. Significant positive correlations between gingiva thickness/implant depth and EPD were only seen at some of the sites. CONCLUSIONS: A small reduction in the papilla level occurred, but no clinical influence on the proximal contact design of the restoration was detected. For the emergence profile, a significant but small discrepancy occurred immediately and continued to increase over time.

Influence of abutment height on peri-implant marginal bone loss: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Whether abutment height can influence peri-implant marginal bone loss has not yet been determined. PURPOSE: The purpose of this systematic review and meta-analysis was to investigate the early and late marginal bone loss around implants with long and short abutment height. MATERIAL AND METHODS: Electronic (PubMed, EMBASE, and Cochrane) and hand literature searches were performed to identify articles published up to May 2018. A random-effects model was used to analyze the weighted mean difference of marginal bone loss between the long and short groups. Potential confounding factors, including implant/abutment connection, healing, and cement- or screw-retained restoration type, were investigated using meta-regression. RESULTS: Fourteen studies fulfilled the inclusion criteria, and 8 were further included in the meta-analysis. Around bone-level implants with a long abutment, marginal bone loss can be reduced significantly in both the early (-0.52 mm; 95% confidence interval [CI]: -0.79 to -0.24; P=.001) and late (-0.53 mm; 95% CI: -1.03 to -0.02; P=.041) period. Among tissue-level implants, however, and compared with the short-abutment group, more bone loss was found during the early stage in the long abutment (weighted mean difference: 0.28 mm; 95% CI: 0.03 to 0.54; P=.031). Meta-regression failed to find any association between confounding factors and early bone loss around bone-level implants. CONCLUSIONS: Within the limitation of this systematic review and meta-analysis, abutment height can influence early bone loss around bone-level implants. However, the evidence is insufficient to determine its impact on late bone loss around bone-level implants and early and late bone loss around tissue-level implants.

A Full-Digital Technique to Mount a Maxillary Arch Scan on a Virtual Articulator.

Mounting casts accurately on an articulator is a prerequisite for the treatment planning/execution of complex dental cases that require occlusal rehabilitation. A full digital approach to transfer the position of maxillary dentition to a virtual articulator, by using intraoral scans and cone beam computed tomography (CBCT) files is presented. This technique offers reduced chairside time and the flexibility of choosing the orientation plane. It can be used in orthognathic surgeries, complex interdisciplinary treatments requiring a CBCT scan with a large field of view, or treatments that already have the head CT or CBCT scans from previous diagnosis/treatment.

Ultrasonography for noninvasive and real-time evaluation of peri-implant tissue dimensions.

AIM: Existing methods for evaluating marginal bone loss and tissue biotype around dental implants present with many limitations. The aim of this study was to examine the accuracy of high-resolution, 3-dimensional ultrasound to measure peri-implant tissue dimensions. MATERIAL AND METHODS: A 25-MHz ultrasound probe prototype was used to scan peri-implant tissues of 17 implants from seven fresh human cadavers. Four ultrasonic measurements were made as follows: the marginal bone level/thickness, and mucosal level/thickness. The readings were statistically compared to cone beam computed tomography (CBCT) and/or open bone measurements. RESULTS: The correlations (r) between the ultrasound and direct/CBCT readings of the four parameters ranged from 0.85 to 0.98 (p < 0.0001). The mean absolute difference in the four parameters between ultrasound-direct and ultrasound-CBCT ranged from 0.033 to 0.24 mm. CONCLUSION: Encouraging evidence is shown that ultrasound can accurately measure peri-implant tissue dimensions. Following clinical trial validations, ultrasound offers potential as a valuable tool to evaluate long-term peri-implant tissue stability without concerns of ionizing radiation and image artefacts around implants.

Impact of timing on soft tissue augmentation during implant treatment: A systematic review and meta-analysis.

BACKGROUND: To achieve a predictable esthetic and functional outcome, soft tissue augmentation has become popular in implant treatment. OBJECTIVES: The aim of this systematic review and meta-analysis was to assess the influence of different timing for soft tissue augmentation during implant treatment on soft tissue conditions and its stability. MATERIAL AND METHODS: Electronic and manual searches for articles written in English up to September 2017 were performed by two independent reviewers. Human clinical studies with the purpose of evaluating outcomes (at least 3-month follow-up) of autogenous soft tissue graft for augmentation during implant treatment, either simultaneous or after implant placement (staged), were included. Cumulative changes of keratinized tissue width (KTW), soft tissue thickness (STT), and mid-buccal mucosal recession (MR) data were analyzed with a random-effects model to compare the postoperative outcomes. RESULTS: Twenty-nine human studies (eight randomized clinical trials, six cohort studies, and 15 case series) that met the inclusion criteria were included. For the overall data, the weighted mean STT gain (1 year after surgery) was 1.03 mm (95% CI: 0.78-1.29 mm), among which the simultaneous group was 1.12 mm (95% CI: 0.75-1.49 mm) and staged group (3-6 months after implant placement) was 0.95 mm (95% CI: 0.58-1.31 mm). There was no statistically significant difference in KTW and MR between 3 months and more than 3 months after surgery. CONCLUSIONS: This review revealed that the stability of soft tissue, in terms of KTW and mid-buccal MR, can be obtained 3 months after surgery. There is no difference between simultaneous and staged soft tissue augmentation during implant treatment, and both procedures significantly enhance KTW and STT.

Accuracy of flapless immediate implant placement in anterior maxilla using computer-assisted versus freehand surgery: A cadaver study.

OBJECTIVE: To compare the accuracy of computer-guided surgery and freehand surgery on flapless immediate implant placement (IIP) in the anterior maxilla. MATERIAL AND METHODS: In this split-mouth design, 24 maxillary incisors in eight human cadaver heads were randomly divided into two groups: computer-guided surgery (n = 12) and freehand surgery (n = 12). Preoperatively, cone-beam computed tomography (CBCT) scans were acquired, and all implants were planned with a software (Blue Sky Plan3). Then, two types of surgeries were performed. To assess any differences in position, the postoperative CBCT was subsequently matched with the preoperative planning. For all the implants, the angular, global, depth, bucco-lingual, and mesio-distal deviations between the virtual and actual implant positions were measured. RESULTS: A significant lower mean angular deviation (3.11 ± 1.55°, range: 0.66-4.95, p = 0.002) and the global deviation at both coronal (0.85 ± 0.38 mm, range: 0.42-1.51, p = 0.004) and apical levels (0.93 ± 0.34 mm, range: 0.64-1.72, p < 0.001) were observed in the guided group when compared to the freehand group (6.78 ± 3.31°, range: 3.08-14.98; 1.43 ± 0.49 mm, range: 0.65-2.31, and 2.2 ± 0.79 mm, range: 1.01-4.02). However, the accuracy of these two approaches was similar for the depth (p = 0.366). In the buccal direction, the mean deviations of both groups showed a general tendency of implants to be positioned facially, occurring more in implants of the freehand group. CONCLUSION: In flapless IIP, computer-guided surgery showed superior accuracy than freehand surgery in transferring the implant position from the planning. However, even with the help of a guide, the final fixture position tends to shift toward a facial direction.