Which is the best choice after tooth extraction, immediate implant placement or delayed placement with alveolar ridge preservation? A systematic review and meta-analysis

Immediate single-tooth implant placement in bony defect sites: A 10-year randomized controlled trial

BACKGROUND

It is unclear whether an intact buccal bony plate is a prerequisite for immediate implant placement in postextraction sockets. The aim of this 10-year randomized controlled trial was to compare peri-implant soft and hard tissue parameters, esthetic ratings of, and patient-reported satisfaction with immediate implant placement in postextraction sockets with buccal bony defects ≥5 mm in the esthetic zone versus delayed implant placement after alveolar ridge preservation.

METHODS

Patients presenting a failing tooth in the esthetic region and a buccal bony defect ≥5 mm after an extraction were randomly assigned to immediate (Immediate Group, n = 20) or delayed (Delayed Group, n = 20) implant placement. The second-stage surgery and provisional restoration placement occurred 3 months after implant placement in both groups, followed by definitive restorations 3 months thereafter. During a 10-year follow-up period, marginal bone levels (primary outcome), buccal bone thickness, soft tissue parameters, esthetics, and patient-reported satisfaction were recorded.

RESULTS

The mean marginal bone level change was -0.71 ± 0.59 mm and -0.36 ± 0.39 mm in the Immediate Group and the Delayed Group after 10 years (p = 0.063), respectively. The secondary outcomes were not significantly different between both groups.

CONCLUSIONS

Marginal bone level changes, buccal bone thickness, clinical outcomes, esthetics, and patients' satisfaction following immediate implant placement, in combination with bone augmentation in postextraction sockets with buccal bony defects ≥5 mm, were not statistically different to those following delayed implant placement after ridge preservation in the esthetic zone.

PLAIN LANGUAGE SUMMARY

Immediate implant placement in case of a failing tooth is a favorable treatment option for patients because it considerably shortens treatment time and the number of surgical treatments. The question is if an intact buccal bone wall is necessary for immediate implant placement. A 10-year study was performed in which 20 patients with a failing tooth in the frontal region of the upper jaw were treated with immediate implant placement and were compared with 20 patients in whom a more conventional treatment strategy was followed in which the failing tooth was first removed and the bone gap restored and the implant placed in a second step. After a 10-year follow-up period, it appeared that the bone around the implant was very stable, gums were healthy, and patients were very satisfied with the result. There was no difference between the two treatment procedures. Such results mean that professionals can discuss the procedure with the patient and apply the individual's preference.

Socket Preservation Using Platelet-Rich Fibrin and Free Gingival Grafts

OBJECTIVE

The present randomised controlled trial is based on the null hypothesis that there is no difference in crestal bone levels (CBLs) following socket preservation (SP) using platelet-rich fibrin (PRF) and free gingival graft (FGG). The aim was to evaluate CBLs following SP using PRF and FGG.

METHODS

This study is a parallel-arm randomised controlled trial. Patients in the test and control groups underwent SP using PRF and FGG, respectively. Intraoral visual examination was performed to clinically assess signs of swelling, pus/abscess, and stability of sutures and graft. Self-rated postoperative pain was assessed after 1 week and 6 months using the visual analogue scale (VAS). At the 6-month follow-up, cone-beam computed tomography was performed to evaluate CBL in mesiodistal and buccolingual dimensions. The preoperative cone-beam computed tomographic images were superimposed with those taken at the 6-month follow-up to compare CBLs. Statistical comparisons were performed and level of significance was set at P < .05.

RESULTS

The test and control groups each comprised 13 individuals with comparable ages. All teeth included in the test and control groups were located in the maxillary aesthetic zone. At the 1-week follow-up, VAS scores were higher in the control than in the test group (P < .01). At the 6-month follow-up, none of the participants reported self-rated pain. The change in buccolingual dimension was greater in the control group than in the test group (P < .05).

CONCLUSIONS

Both FGG and PRF are effective techniques for SP; however, the latter technique is more effcacious in maintaining buccolingual dimensions of the extraction socket.

Accuracy of immediately placed implants using surgical guides from different 3-dimensional printers: An in vitro study

AIM

The aim of this study was to evaluate the accuracy of 3-dimensional (3D)-printed surgical guides for fully guided immediate implants from different manufacturers.

METHODS

Eighteen 3D printed fully guided surgical guides (split into 3 groups [n = 6] according to their manufacturer: Company, Desktop, or Lab), were used to place 72 implants (n = 24) in identical maxillary models. After placement, the mean global, angular, mesiodistal, buccopalatal, and vertical deviation at the platform and apex of the placed implants, relative to their preoperatively planned positions, was calculated.

RESULTS

Significant differences in global apex deviation, angular deviation, mesiodistal apex deviation, and vertical platform and apex deviation were found between the Lab and Desktop groups (p ≤ 0.007). Significant differences in mesiodistal platform and apex deviation and buccopalatal apex deviation were also found between the Company and Desktop groups (p ≤ 0.005). Finally, significant differences in buccopalatal apex deviation, and vertical platform and apex deviation were found between the Company and Lab groups (p ≤ 0.003). Mean differences between guide groups across all parameters never exceeded 0.5 mm or 1°.

CONCLUSIONS

The choice of 3D printer has a significant effect on the accuracy of fully guided immediate implants. However, the clinical relevance of these differences may be considered limited.

Clinical outcomes of 3-5 years follow-up of immediate implant placement in posterior teeth: a prospective study

BACKGROUND

Immediate implant placement in posterior teeth has become popular in recent years. However, only a few studies focused on evaluating the long-term success of immediate implant placement.

PURPOSE

To analyze the clinical outcomes of immediate implant placement in the posterior region with conventional loading with 3-5 years follow-up following the International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference.

METHOD

The study was done in 25 bone-level implants (Straumann® SLActive® bone level tapered implant, Straumann®, Basel, Switzerland) in 19 patients who underwent immediate implant placement in a posterior tooth with conventional loading with 3-5 years follow-up. The overall success and survival of these placements were evaluated following the International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference using chart records, clinical examination, radiographic evaluation, and outcomes measurement. Patient satisfaction was evaluated by using a numeric rating scale. The biological and technical status, modified Pink Esthetic Score (mPES), complications, and marginal bone change were also evaluated. The analysis was done using SPSS version 21 (SPSS Inc., Chicago, IL, USA). The data were analyzed using a paired samples t-test.

RESULTS

It was found that 24 out of the 25 (96%) dental implants survived for an average of 57 ± 8.07 months. All of the 24 surviving dental implants were considered an operational success. The average mPES was 9.75 ± 0.44. The major prosthetic complications seen were: (1) proximal contact loss (41.67%), (2) loosening of the screw (8.33%), and (3) cement debonding (4.17%).

CONCLUSIONS

Immediate implant placement in a posterior tooth with conventional loading yields a predictable result with some complications. The most prominent complications were proximal contact loss, followed by loosening of the screw and cement debonding. The implant survival rate was 96% at a mean time follow-up of 4 years and 9 months.

Comprehensive view of the posterior mandibular ridge morphology

The anatomy of the posterior mandibular ridge and the anatomical structures present in this region are important in the planning and execution of dental treatments. The aim of this study was to examine all forms of alveolar ridge in detail to provide a comprehensive description of the posterior mandibular ridge. This study included 1865 cross-sectional sections of cone beam computed tomography scans obtained from 511 Iranian patients with a mean age of 48.14 years (280 female, 231 male). The alveolar ridge was described based on the ridge shape, including the existence and location of convexity and concavity. The morphology of the posterior mandibular ridge was categorized into 14 types: straight, pen shape, oblique, D type, B type, kidney, hourglass, sickle, golf club, toucan beak, tear, cudgel, basal, and saddle. Among the alveolar ridge types, the straight type in the premolar region and toucan beak type in the molar region were most frequent in the female, male, dentulous, and edentulous ridges. This study found significant differences in alveolar ridge morphology according to sex, dental status, and region of the ridge (all P < 0.001). In conclusion, the morphology of the alveolar ridge varies significantly between the sexes and between dentulous and edentulous locations.

Oral health-related quality of life (OHRQoL) and implant therapy: A prospective multicenter study of preoperative, intermediate, and posttreatment assessment

The purpose of this multicenter continuation study was to use high patient numbers in order to generate reliable statements regarding the association between different implant indications and OHRQoL. Patients with various types of indication for dental implants, ranging from single tooth loss to edentulous jaws, were included. Quality of life relating to dental implants was assessed through the oral health impact profile (OHIP-G-21), which has a summary score from 0 to 20 in healthy patients. In total, 16 253 patients from 29 centers (European Centers for Dental Implantology (ECDI)) were involved in the study between 2009 and 2021.8251 patients (50.7%) completed the questionnaire after implant insertion, and 4996 patients (30.7%) after prosthodontic treatment. The average age was 54 years (range 18-88 years). Posterior single-tooth gap (28.5%) and free-end gap (27.8%) were the most frequent indications. The preoperative OHIP-G-21 score for all patients was 32.81 (SD 11.92), while the score during the healing period was 30.00 (SD 10.72), and after completion of treatment 27.24 (SD 9.26) (p < 0.001). The most significant improvements in OHIP-G-21 scores were in the indication of edentulous jaw (phase 1, 41.81 (SD 15.53); phase 2, 35.39 (SD 14.22); phase 3, 29.60 (SD 10.12) (p < 0.001). The study revealed significant improvements in the most frequently reported problems (chewing, serious concerns, appearance) (p < 0.001). Insertion of dental implants and prosthodontic rehabilitation led to an improved OHRQoL for patients with all indications for dental implants. Special attention should be paid to patients with edentulous jaw, since in comparison with other indications it had the greatest impact on improving OHRQoL. The psychological dissatisfaction scale of the OHIP-G-21 represented the most important factors for patients, and these scores were substantially influenced by implant therapy. Thus, treating physicians should increase their focus on these factors, in order to avoid dissatisfaction and increase the likelihood of complete implant therapy success.

The fusion of keratinized epithelium, an indication of early implant placement in the aesthetic area: an animal study

BACKGROUND

In the period of the early implant placement, the socket is mainly occupied by provisional matrix (PM). Keratinized epithelium (KE) is critical for primary wound closure. Although both KE and PM are important, the detailed relationship among migrating KE, PM formation and indication of the early implant placement is still unclear.

OBJECTIVE

This research aimed to locate a healing stage of KE with highest osteogenic PM formation after tooth extraction, which could be treated as the optimal time point for early implant placement.

MATERIAL AND METHODS

Mice were sacrificed on days 1, 2, 3, 4 and 6 after incisor extraction. Clinical, histological, and immunohistochemical evaluations of the extraction sockets were performed, and statistical analyses were conducted. We then inserted implants into the PM with the greatest bioactivity and observed its osseointegration pattern for 3, 10, 17 and 30 days.

RESULT

When KE fusion was reached, sockets were dominated by PM with the greatest expression of osteocalcin (OC, P < 0.05) and high levels of CD34 and Runx2. OC and Runx2 expression were positively correlated with KE coverage (P < 0.05). When the implant was inserted at 4 days' healing, the PM maintained its osteogenic ability, and osseointegration proceeded perfectly.

CONCLUSION

The migration of KE was correlated with the formation of highly osteogenic and angiogenic PM. And the fusion of KE could be treated as an indication for early implant placement.

Perigraftitis and implant therapy: A case report

BACKGROUND

A previous case study reported periimplantitis and concomitant perigraftitis of a second implant placed at a site that had alveolar ridge preservation three decades earlier. Infection at the site persisted 4 months after implant removal by flapless implant reversal. A flap was subsequently reflected, the grafted bone was removed, and a second alveolar ridge preservation was performed with a freeze-dried bone allograft. The publication reported infection resolved, and the site healed uneventfully. However, it is unknown if placement of another implant at the site would be successful. The purpose of this paper is to report on the findings at surgical reentry and outcome of the third implant.

METHODS

Eleven months after the second alveolar ridge preservation, the site was reentered. The bone graft was found to be partially soft tissue encapsulated. All encapsulated graft materials and soft tissue were removed. An implant was placed, and the alveolar defect was grafted with a demineralized bone allograft. Seventeen months after implant placement, a buccal free gingival graft was performed during which the crestal bone adjacent to the implant was found to be hard and corticated. The implant was deemed to be osseointegrated and restored after soft tissue healing.

RESULTS

Twenty-five months after implant placement, the third implant remained functional and asymptomatic with the peri-implant bone exhibiting normal trabeculation.

CONCLUSIONS

Implant therapy can be successful following treatment and resolution of perigraftitis.

KEY POINTS

Perigraftitis may play a contributing role in the biologic complications of implants that have been placed into grafted bone. Perigraftitis may be successfully resolved by completely removing all grafted bone. Once perigraftitis has been eliminated, an implant may be successfully placed.

Surface demineralized freeze-dried bone allograft followed by reimplantation in a failed mandibular dental implant

The removal of a failed implant with high torque causes significant damage to the surrounding tissue, compromising bone regeneration and subsequent osseointegration in the defect area. Here, we report a case of carrier screw fracture followed by immediate implant removal, bone grafting and delayed reimplantation. A dental implant with a fractured central carrier screw was removed using the bur-forceps technique. The resulting three-wall bone defect was filled with granular surface demineralized freeze-dried bone allograft (SD-FDBA). Cone-beam computerized tomography was performed at 1 week, 6 months and 15 months postoperatively and standardized for quantitative evaluation. The alveolar bone width and height at 15 months post-surgery were about 91% of the original values, with a slightly lower bone density, calculated using the gray value ratio. The graft site was reopened and was found to be completely healed with dense and vascularized bone along with some residual bone graft. Reimplantation followed by restoration was performed 8 months later. The quality of regenerated bone following SD-FDBA grafting was adequate for osseointegration and long-term implant success. The excellent osteogenic properties of SD-FDBA are attributed to its human origin, cortical bone-like structure, partly demineralized surfaces and bone morphogenetic protein-2-containing nature. Further investigation with more cases and longer follow-up was required to confirm the final clinical effect.

Is alveolar ridge preservation an overtreatment?

The morphology and dimensions of the postextraction alveolar ridge are important for the surgical and restorative phases of implant treatment. Adequate new bone formation and preservation of alveolar ridge dimensions following extraction will facilitate installation of the implant in a restorative position, while preservation of soft tissue contour and volume is essential for an aesthetic and implant-supported restoration with healthy peri-implant tissues. Alveolar ridge preservation (ARP) refers to any procedure that aims to: (i) limit dimensional changes in the alveolar ridge after extraction facilitating implant placement without additional extensive bone and soft tissue augmentation procedures (ii) promote new bone formation in the healing alveolus, and (iii) promote soft tissue healing at the entrance of the alveolus and preserve the alveolar ridge contour. Although ARP is a clinically validated and safe approach, in certain clinical scenarios, the additional clinical benefit of ARP over unassisted socket healing has been debated and it appears that for some clinicians may represent an overtreatment. The aim of this critical review was to discuss the evidence pertaining to the four key objectives of ARP and to determine where ARP can lead to favorable outcomes when compared to unassisted socket healing.

Assessment of Various Risk Factors for Biological and Mechanical/Technical Complications in Fixed Implant Prosthetic Therapy: A Retrospective Study

The goals of this research were to determine the influence of several factors on implants' biological and technical complications in posterior fixed implant prosthetic therapy.

MATERIALS AND METHODS

The study group consisted of 67 edentulous patients (mean age: 63.88 ± 11.709 yrs; 20 males, 47 females) with implant prosthetic therapy for posterior edentulism. A total of 76 implant-supported fixed partial dentures (IP-FPDs) and 178 implants were assessed using clinical and paraclinical assessments. Risk factors for biological complications (peri-implantitis) and technical complications were determined by using the Pearson Chi-squared test and multivariate analysis.

RESULTS

The implant success (the absence of biological and mechanical/technical complications) was 66.30%. The prevalence of biological complications was 13.5%. The prevalence of technical complications was 28.70%. Variables that were associated with a higher risk of peri-implantitis were poor oral hygiene and bruxism. In univariate analysis, poor oral hygiene increased the risk of peri-implantitis 5.778 times and bruxism 5.875 times. Variables that were associated with a higher risk of mechanical/technical complications were age group > 60 yrs, smoking, history of periodontal disease, and bruxism. In univariate analysis, the risk of technical complications increased 4.14 times for patients in the age group > 60 years (vs. age group 40-60 years) and 20.5 times for patients with bruxism. Bruxism and smoking were significant predictors of mechanical/technical complications in the multivariate model.

CONCLUSIONS

In univariate models, patients with poor oral hygiene and bruxism have an increased risk of peri-implantitis. In multivariate models, we did not identify significant predictors of peri-implantitis. Age group > 60 yrs, smoking, history of periodontal disease, bone grafting, and bruxism are risk factors for the increase in the mechanical/technical complication rate. In the multivariate model, smoking and bruxism are significant predictors of the mechanical/technical complications.

Survival Rate of Ultrawide Diameter Implants Placed into Molar Postextraction Sockets and in Function for Up to 144 Months

PURPOSE

Innovations in macroimplant design, specifically ultrawide implants 7.0 mm or greater in diameter, have allowed immediate molar replacement. This is a retrospective study assessing the survival rates of ultrawide diameter implants (7.0, 8.0, 9.0 mm) immediately placed into molar extraction sockets. Implants were followed up to 144 months postplacement.

MATERIALS AND METHODS

A retrospective study was conducted of all patients treated in a private surgical practice between January 1, 2008 and December 31, 2020, who received ultrawide dental implants (7.0, 8,0, 9.0 mm.) placed immediately into molar extraction sockets. Wide diameter healing abutments were placed on all implants at the time of surgery. Abutments and crown restorations were fabricated after at least 4 months of unloaded healing. Patient age, sex, implant location and implant diameters were examined for survival. Insertion torque values at the time of placement and time in function were also evaluated. Biometric statistics were computed with p-values (<0.05. Descriptive and bivariate statistics were computed; p-values were set at 0.05.

RESULTS

Five hundred forty-four patients (225 males; 319 females) average age 62.5 years (range 27 to 95) had 563 implants placed. Five hundred thirty-five of five hundred sixty-three (535/563) implants survived; 28 failed [clinical survival rate (CSR) 95.03%]. Number and time in function were: 0 to 12 years 100%; 0 to 9 years 85%; 0 to 6 years 69%; 0 to 3 years 35% or 10 to 12 years 16%; 7 to 9 years 16%; 4 to 6 years 34%; 0 to 3 years 35%. No significant differences were found between sex and implant failures (p = 0.22). Maxillary (266/285; 93.3%) and mandibular (269/278; 96.8%) implant CSRs were not significantly different. Three implant diameters were used: 7.0 mm (206/563) [36.6%]; 8.0 mm (267/563) [47.4%]; 9.0 mm (90/563) [15.9%]. Clinical survival rates were: 7.0 mm (201/206) [97.6%]; 8.0 mm (252/267) [94.4%]; 9.0 mm (82/90) [91.1%]. Mean age for patients with failed implants did not show any significant differences (p = 0.1398). Fifteen of the 28 failed implants failed within 120 days of surgical placement (prior to definitive restoration; [53.6%]; 4 implants failed between 4 and 12 months [14.3%]; 9 implants failed at least 1-year postloading [32.1%].

CONCLUSIONS

The results of this long-term retrospective study regarding ultrawide diameter implants suggested that these implants were viable treatment options for immediate molar replacement following tooth extraction in either jaw with an unloaded healing protocol. High clinical survival rates were reported over a 144-month (12-year) timeframe.

Immediate implant placement with simultaneous bone augmentation versus delayed implant placement following alveolar ridge preservation: A clinical and radiographic study

OBJECTIVE

The present study aimed to evaluate the clinical and radiographic outcomes of immediate implant placement (IIP) with guided bone regeneration (GBR) as compared to delayed implant placement (DIP) following alveolar ridge preservation (ARP) and to identify the potential risk factors influencing these outcomes.

METHODOLOGY

A total of 56 patients (IIP = 28 vs. DIP = 28) with class I or II bony defects received 56 implants were included. GBR procedure using Bio-Oss® bone substitute mixed with advanced platelet-rich fibrin (A-PRF) and covered by Bio-Gide® membrane and additional A-PRF membrane was performed either simultaneously with the IIP or earlier at the time of ARP in DIP. Clinical and 3-D radiographic analyses of bone level, thickness, and density were performed at three-time intervals (T1, immediately; T2, 6-7 months; and T3, 1.5 to 2 years post-implantation), corresponding to the neck, coronal, middle, and apex of implants.

RESULTS

The survival rate was 100% in both groups. IIP showed significant favorable outcomes regarding distal marginal bone level (anterior maxilla, T1-T3) and neck and coronal horizontal facial bone thickness (HFBT) (posterior maxilla, T1; and anterior maxilla, T1-T3, respectively) compared to DIP. However, DIP showed significant facial bone density at the neck and coronal parts in the anterior maxilla (T1) and the coronal part in the posterior maxilla (T3). The facial marginal bone level change was positively correlated with HFBT change (P = 0.007), which is negatively correlated with the secondary implant stability (P = 0.019). The implant region (anterior or posterior maxilla) was the only factor affecting on Implant stability quotient value (ISQ) and change in HFBT (P ˂ 0.05).

CONCLUSION

Overall, the IIP combined with GBR in the post-extraction sites with pre-implant class I or II bony defects had some favorable outcomes compared to DIP after ARP. However, the clinical outcomes, ISQ value, and changes in bone level, thickness, and density from T1-T3 were comparable.

Effect of leukocyte-platelet-rich fibrin in bone healing around dental implants placed in conventional and wide osteotomy sites: A pre-clinical study

Leukocyte-platelet-rich fibrin (L-PRF) has been suggested for gap management for immediate implant placement when the distance is greater than 2 mm. However, there remains a paucity in hierarchically designed research to support this application. The present study aimed to evaluate the effect of L-PRF on the osseointegration parameters of dental implants placed after conventional osteotomy of surgically created bone defects that simulate post extraction sockets in a canine model after 3, 6, and 12 weeks in vivo. Eighty dental implants (Intra-Lock, Boca Raton, FL) were placed in the radius of 13 beagle dogs. The experiment consisted of 4 groups (n = 20 implants/group): 1) Regular osteotomy (Reg n/L-PRF); 2) Regular osteotomy and implant placement with L-PRF membrane (Reg L-PRF); 3) Wide osteotomy with no gap management performed, where an osteotomy/bony defect (6 mm of diameter and ~5 mm deep) was created to simulate immediate implant placement in post-extraction sockets, and the gap was left for spontaneous healing (Wide nL-PRF); and 4) Wide osteotomy with L-PRF gap management (Wide L-PRF). L-PRF membranes were obtained by blood drawn from each subject and centrifuged at 2700 rpm (408 RCF-clot) for 12 min. In the experimental groups where L-PRF was utilized, the membrane was inserted into the osteotomy site prior to implant placement. Six dogs had implants placed in the radius for 3 weeks; and 7 dogs had implants placed in the left radius for 6 weeks and in the right radius for 12 weeks. At the corresponding experimental time points, samples were harvested, and subjected to histological processing for qualitative and quantitative analyses, via bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO). Qualitative analysis demonstrated increased amounts of bone formation around the implant and within the healing chambers over time for all groups. While comparable histological features were observed for both Reg groups (L-PRF and nL-PRF), the gap management performed in Wide L-PRF group resulted in effective gap filling with improved bone growth in close proximity to the implant surface. Quantitative analyses of BIC and BAFO yielded higher values for both variables at 3 weeks for Wide L-PRF (~38% and ~56% respectively) compared to Wide nL-PRF (~20% for BIC and BAFO) (p < .03). No statistical differences were detected between Wide groups at 6 and 12 weeks, neither between Reg groups, independent of the association with or without the L-PRF membrane at all healing times. L-PRF placed within wide osteotomies, prior to implant placement, resulted in increased early bone formation compared to unfilled wide osteotomies at the early healing time (3 weeks in vivo).

Immediate versus delayed implant placement in the esthetic zone: a prospective 3D volumetric assessment of peri-implant tissue stability

PURPOSE

To evaluate the volumetric stability of peri-implant soft and hard tissue prospectively, this study compared immediate versus delayed implants placed in the anterior esthetic region.

METHODS

This non-randomized controlled clinical study included 25 patients, who received an immediate (type 1) or a delayed (type 4) implant placement for the replacement of a single anterior tooth. The anterior maxillae were intraorally scanned at three timepoints: before surgery (S0), 6 months (S1), and 12 months (S2) after surgery. A specific region of interest (ROI), divided into marginal and apical regions, was determined and superimposed for volumetric changes analysis. At 6 and 12 months, the probing depth (PD), bleeding/suppuration on probing (BOP/SUP), modified plaque index (PI), keratinized mucosa (KM) width, mucosal recession (MR), and implant stability (PTV) by means of periotest were recorded.

RESULTS

Between S0-S2, tissue surrounding immediate implants was reduced in 0.37 ± 0.31 mm, whereas delayed implants gained 0.84 ± 0.57 mm mean tissue volume. Peri-implant tissue loss at type 1 implants occurred primarily in the marginal section of the ROI (0.42 ± 0.31 mm), whereas tissue gain at type 4 implants occurred mainly in the apical section (0.83 ± 0.51 mm). These values were significantly different between both groups for the entire ROI (p = 0.0452) and the marginal region (p = 0.0274). In addition, the mean buccal KM width around type 1 implants was significantly wider in comparison with the type 4 implants group after 12 months (p = 0.046). There were no significant differences between groups regarding PD, BOP/SUP, or PTV.

CONCLUSIONS

The results suggest that type 1 implants placed in the esthetic region experience more tissue loss than type 4 implants, thus marginal tissue remodeling should be considered for planning immediate implants placement in the anterior maxillae.

A comparison between anorganic bone and collagen-preserving bone xenografts for alveolar ridge preservation: systematic review and future perspectives

After tooth extraction, dimensional changes affect the alveolar socket, leading to loss in alveolar bone height and width. Histological modifications also occur, with initial formation of a blood clot that is replaced with granulation tissue and subsequently with a provisional connective tissue matrix. Spontaneous healing ends with socket filling with woven bone, which is gradually replaced with lamellar bone and bone marrow. Adequate alveolar ridge dimensions and bone quality are required to assure optimal stability and osseointegration following dental implant placement. When a tooth is extracted, alveolar ridge preservation (ARP) procedures are an effective method to prevent collapse of the post-extraction socket. Heterologous bone is widely chosen by clinicians for ARP, and anorganic bone xenografts (ABXs) made bioinert by heat treatment represents the most used biomaterial in clinical applications. Collagen-preserving bone xenografts (CBXs) made of porcine or equine bone are fabricated by less invasive chemical or enzymatic treatments to remove xenogenic antigens, and these are also effective in preserving post-extraction sites. Clinical differences between anorganic bone substitutes and collagen-preserving materials are not well documented in the literature but understanding these differences could clarify how processing protocols influence biomaterial behavior in situ. This systematic review of the literature compares the dimensional changes and histological features of ABXs versus CBXs in ridge preservation procedures to promote awareness of different bone xenograft efficacies in stimulating the healing of post-extraction sockets.

Immediate versus Delayed Implantation for Single-Tooth Restoration of Maxillary Anterior Teeth: A Comparative Analysis on Efficacy

Objective

The present research is aimed at determining the efficacy of immediate implantation (II) and delayed implantation (DI) for single-tooth restoration of maxillary anterior teeth.

Methods

From February 2019 to June 2020, 80 patients who received single-tooth restoration of maxillary anterior teeth in Suzhou Kowloon Hospital, Shanghai Jiaotong University School of Medicine, were included, among which 38 cases with DI restoration were used as the control group (CG), and the remaining 42 cases with II were used as the research group (RG). The complications that occurred were recorded. Besides, subjective satisfaction (Visual Analogue Scale (VAS)), aesthetic effect after anterior teeth trauma restoration (Pink Esthetic Score (PES)), aesthetics of dental hard tissue (White Esthetic Score (WES)), pocket depth assessed by pure titanium periodontal probe, implant stability (Implant Stability Quotient (ISQ)), and oral health-related quality of life (Oral Health Impact Profile- (OHIP-) 14) were evaluated. Attachment height, general look, color, and chewing function were all much higher in RG than in CG, according to the evaluation results. Furthermore, at 3 months, 6 months, and 12 months after surgery, RG had greater PES, WES, ISQ, and OHIP-14 scores, while the periodontal depth was decreased. In both groups of patients, the incidence of complications was similar, with no discernible differences.

Evaluation of Deviations between Computer-Planned Implant Position and In Vivo Placement through 3D-Printed Guide: A CBCT Scan Analysis on Implant Inserted in Esthetic Area

Background: Implant rehabilitation in cases of monoedentulism in the esthetic area is a challenge for the clinician. The aim of our study was to test the diagnostic–therapeutic accuracy of computer-guided implant placement in the esthetic area. Methods: Postimplant surgery cone beam computed tomography (CBCT) scans were retrospectively analyzed to assess the accuracy of computer-guided implant placement compared to the preoperative computer-digital planned implant position. We selectively enrolled CBCT scans of patients who underwent immediate or delayed implant placement of a single maxillary incisor, treated with computer-guided implant surgery through a tooth-supported digitally designed 3D printed guide. Our analysis consisted of three digital measurements: the mean deviation of the implant axis, and the mean mesiodistal implant deviation measured both at the apex and at the head of the implant. Results: A total of 95 implants were placed in 95 patients (60 Males, 35 Females; age from 27 to 45-year-old). Congruence analysis showed a mean deviation of implant axis of 1.04° ± 0.56° in sagittal projection, a mean mesiodistal implant deviation between adjacent teeth of 0.14 mm ± 0.07 mm at implant head level and 0.8 mm ± 0.3 mm at the apex in axial projection. Conclusions: computer-guided implant placement through a tooth-supported guide was extremely accurate in the esthetic area because the deviations between the real implant position and the preoperative planning was not clinically relevant.

Influence of different diameter reductions in the labial neck region on the stress distribution around custom-made root-analogue implants

This study was designed to investigate the influence of diameter reductions on the stress distribution around root-analogue implants via 3D finite element analysis. Four root-analogue implant models with different diameter reductions (0, 1, 2, or 3 mm), a traditional threaded implant and congruent bone models were created through reverse engineering. A 100-N force was applied parallel with and in a 45° angle to the implant axis, respectively. The stress concentration in the labial neck area around implants with 1-2 mm diameter reduction was lower than seen with no reduction. When the implant diameter was reduced by 3 mm, there were obvious stress concentrations in both implant and bone (the maximum stress was 206  and 111 MPa, respectively). In other groups, the maximum stress was 65.1 MPa in the bone and 108 MPa in the implant. Additionally, the stress concentration in the bone around the root-analogue implant when the implant diameter was reduced by 0-2 mm (maximum stress of 65.1 MPa) was obviously smaller than that around the traditional implant (maximum stress 130.4 MPa). Reducing the diameter of maxillary central incisor root-analogue implants by up to 2 mm next to the labial cortical bone could help disperse stress.

Does initial buccal crest thickness affect final buccal crest thickness after flapless immediate implant placement and provisionalization: A prospective cone beam computed tomogram cohort study

BACKGROUND

Flapless immediate implant placement and provisionalization (FIIPP) in the aesthetic zone is still controversial. Especially, an initial buccal crest thickness (BCT) of ≤1 mm is thought to be disruptive for the final buccal crest stability jeopardizing the aesthetic outcome.

PURPOSE

To radiographically assess the BCT and buccal crest height (BCH) after 1 year and to calculate the correlation between initial and final achieved BCT.

MATERIALS AND METHODS

The study was designed as a prospective study on FIIPP. Only patients were included in whom one maxillary incisor was considered as lost. In six centers, 100 consecutive patients received FIIPP. Implants were placed in a maximal palatal position of the socket, thereby creating a buccal space of at least 2 mm, which was subsequently filled with a bovine bone substitute. Files of preoperative (T0), peroperative (T1) and 1-year postoperative (T3) cone beam computed tomogram (CBCT) scans were imported into the Maxillim™ software to analyze the changes in BCT-BCH over time.

RESULTS

Preoperatively, 85% of the cases showed a BCT ≤1 mm, in 25% of the patients also a small buccal defect (≤5 mm) was present. Mean BCT at the level of the implant-shoulder increased from 0.6 mm at baseline to 3.3 mm immediate postoperatively and compacted to 2.4 mm after 1 year. Mean BCH improved from 0.7 to 3.1 mm peroperatively, and resorbed to 1.7 mm after 1 year. The Pearson correlation of 0.38 between initial and final BCT was significant (p = 0.01) and therefore is valued as moderate. If only patients (75%) with an intact alveolus were included in the analysis, still a "moderate correlation" of 0.32 (p = 0.01) was calculated.

CONCLUSIONS

A "moderate correlation" was shown for the hypothesis that "thinner preoperative BCT's deliver thinner BCT's" 1 year after performing FIIPP.

Alveolar Bone Marrow Gli1+ Stem Cells Support Implant Osseointegration

Osseointegration is the key issue for implant success. The in vivo properties of cell populations driving the osseointegration process have remained largely unknown. In the current study, using tissue clearing-based 3-dimensional imaging and transgenic mouse model-based lineage tracing methods, we identified Gli1+ cells within alveolar bone marrow and their progeny as the cell population participating in extraction socket healing and implant osseointegration. These Gli1⁺ cells are surrounding blood vessels and do not express lineage differentiation markers. After tooth extraction and delayed placement of a dental implant, Gli1⁺ cells were activated into proliferation, and their descendants contributed significantly to new bone formation. Ablation of Gli1⁺ cells severely compromised the healing and osseointegration processes. Blockage of canonical Wnt signaling resulted in impaired recruitment of Gli1⁺ cells and compromised bone healing surrounding implants. Collectively, these findings demonstrate that Gli1⁺ cells surrounding alveolar bone marrow vasculature are stem cells supporting dental implant osseointegration. Canonical Wnt signal plays critical roles in regulating Gli1⁺ stem cells.

Dimensional and histomorphometric evaluation of biomaterials used for alveolar ridge preservation: a systematic review and network meta-analysis

OBJECTIVES

This systematic review and network meta-analysis aimed to answer to the following questions: (a) In patients undergoing alveolar ridge preservation after tooth extraction, which grafting material best attenuates horizontal and vertical ridge resorption, as compared to spontaneous healing?, and (b) which material(s) promotes bone formation in the extraction socket?

MATERIALS AND METHODS

The MEDLINE, SCOPUS, CENTRAL, and EMBASE databases were screened in duplicate for RCTs up to March 2021. Two independent authors extracted the data and assessed the risk of bias of the included studies. Primary outcomes were ridge horizontal and vertical dimension changes and new bone formation into the socket. Both pairwise and network meta-analysis (NMA) were undertaken to obtain estimates for primary outcomes and compare different grafting materials.

RESULTS

Eighty-eight RCTs were included, with a total of 2805 patients and 3073 sockets. Overall, a total of 1740 sockets underwent alveolar ridge preservation with different materials (1432 were covered by a membrane). Pairwise meta-analysis showed that, as compared to spontaneous healing, all materials statistically significantly reduced horizontal and vertical shrinkage. According to the multidimensional scale ranking of the NMA, xenografts (XG) and allografts (AG), alone or combined with bioactive agents (Bio + AG), were the most predictable materials for horizontal and vertical ridge dimension preservation, while platelet concentrates performed best in the percentage of new bone formation.

CONCLUSIONS

Alveolar ridge preservation is effective in reducing both horizontal and vertical shrinkage, as compared to untreated sockets. NMA confirmed the consistency of XG for ridge dimension preservation, but several other materials and combinations like AG, Bio + AG, and AG + alloplasts, produced even better results than XG in clinical comparisons. Further evidence is needed to confirm the value of such alternatives to XG for alveolar ridge preservation. Bio + AG performed better than the other materials in preserving ridge dimension and platelet concentrates in new bone formation. However, alloplasts, xenografts, and AG + AP performed consistently good in majority of the clinical comparisons.

CLINICAL RELEVANCE

XG and Bio + AG demonstrated significantly better performance in minimizing post-extraction horizontal and vertical ridge dimension changes as compared with other grafting materials or with spontaneous healing, even if they presented the worst histological outcomes. Allografts and other materials or combinations (AG + AP) presented similar performances while spontaneous healing ranked last.

Variations in Soft and Hard Tissues following Immediate Implant Placement versus Delayed Implant Placement following Socket Preservation in the Maxillary Esthetic Region: A Randomized Controlled Clinical Trial

Introduction

Although retrospective analysis has shown immediate placement of implants (IIP) in the maxillary esthetic zone showing promising outcomes compared to delayed placement of implants following socket preservation (DIP), a direct comparison in a prospective, well-designed randomized fashion with adequate power analysis between the two implant placement protocols is still lacking. This study is aimed at radiographically evaluating the effect of IIP after extraction as compared to implant placed in preserved sockets 4 months following extraction (DIP) in terms of changes in buccal plate thickness(CBT) after 6 months of healing and evaluation of pink esthetic score (PES) for assessment of soft tissue changes and patient-related outcome measures (PROMs) using visual analogue scale (VAS).

Materials and Methods

25 implants were placed immediately following extraction in the IIP group, and 25 implants were placed four months following socket preservation with demineralized bovine bone mineral (DBBM) and advanced platelet-rich fibrin (A-PRF) in the DIP group, control group, in the maxillary esthetic region. CBCT was taken preoperatively and 6 months postoperatively to assess the dimensional changes in the buccal bone plates(CBT). PES and PROMs for pain threshold and patient satisfaction using VAS were evaluated at the time of implant placement and 6 months postoperatively.

Results

Significant differences in mean reduction in buccal plate thickness (CBT) were found in the test group (IIP) 0.2 ± 0.02 compared to the control group (DIP) which showed a mean reduction in CBT of 0.4 ± 0.1 (p < 0.001) at the end of 6 months. Although there was no statistically significant difference in PES between the groups, there was a significant difference between the groups when individual values of PES were compared at p < 0.001.

Conclusion

The IIP group showed lesser reduction in CBT and a better PES which is an important clinical information which could be translated clinically in situations where implant placement is planned in the maxillary esthetic region. This trial is registered with CTRI/2019/06/019723.

Long-term outcomes of maxillary single-tooth implants in relation to timing protocols of implant placement and loading: Systematic review and meta-analysis

OBJECTIVES

The aim of the present systematic literature review was to determine whether long-term treatment results with single-tooth implants may differ depending on the timing of implant placement in relation to tooth extraction (immediate IP/early EP/delayed DP) and the timing of prosthetic loading (immediate IL/early EL/delayed DL).

MATERIAL AND METHODS

Electronic and manual searches were performed to identify studies reporting on long-term results (survival rate and/or marginal bone resorption after ≥3 years) of maxillary single-tooth implants in the aesthetic zone using defined placement and loading protocols. Comparative trials were subjected to meta-analyses whilst data from single-arm studies were pooled to evaluate differences between timing protocols.

RESULTS

A total of 7 controlled trials were considered for meta-analyses: immediate loading was compared to delayed loading in 3 studies on immediate placement (IPIL vs. IPDL, p = .306) and in 2 studies on delayed placement (DPIL vs. DPDL, p = 1.000) whilst 2 studies compared early versus delayed placement with delayed loading (EPDL vs. DPDL, p = .600), however, without significant differences. Pooled data analysis of 29 studies (965 implants) did not show differences between timing of placement or loading as well as marginal bone remodelling. No impact of the one abutment - one time concept, flap design and simultaneous bone or soft tissue augmentation could be established.

CONCLUSIONS

Insufficient data are available for meta-analytic comparison of all combinations of implant placement and loading protocols.

Biological and esthetic outcome of immediate dental implant with the adjunct pretreatment of immediate implants with platelet-rich plasma or photofunctionalization: A randomized controlled trial

Aim

The purpose of the study was to assess biological and esthetic outcomes of immediate dental implant in esthetic zone with the adjunct pretreatment of immediate implants with photofunctionalization or platelet-rich plasma in comparison to standard tapered root form implant without pretreatment.

Settings and Design

Patients visiting department of Prosthodontics of a tertiary care health Institution. Design of the study was randomized controlled trial.

Materials and Methods

Ninety subjects who required replacement of maxillary anterior teeth immediately after extraction were selected and randomly divided into three groups: control group and two case groups. Two case groups were treated with immediate implants with pretreatment with Photofunctionalization (PF group) or platelet-rich plasma (PRP group). Delayed loading protocol was followed with prosthesis given after 6 months. Follow-up was performed at 2nd and 4th weeks and 2, 4, 6, and 12 months (P < 0.05). Biological outcomes (mean marginal bone loss, implant stability), esthetic outcome (pink esthetic score and white esthetic score), and success and survival rate were evaluated.

Statistical Analysis Used

Outcomes were compared using one-way ANOVA, while intragroup changes with baseline and follow up were assesed using repeated-measures ANOVA. Statistical analyses were performed using Statistical Package for Social Sciences version 25.0 (SPSS Inc., Chicago, IL, USA). The level of significance was set at <.05.

Results

Mean marginal bone loss was not significantly different in PF group and PRP group than the control group. PF group and PRP group showed significantly greater implant stability as compared to the control group. Pink and white esthetic scores were not significantly different among groups.

Conclusion

Pretreatment of commercial dental implants with PF or PRP exhibited a statistically significant difference in implant stability but not with other outcomes.

What grafting materials produce greater alveolar ridge preservation after tooth extraction? A systematic review and network meta-analysis

A systematic review and network meta-analysis was conducted to compare different bone-substitute materials used for alveolar ridge preservation after tooth extraction. The electronic search was carried out on Embase, PubMed, Cochrane Library, Web of Science, Scopus, LILACS, and grey literature up to March 22, 2020 (registration number INPLASY202030005). Only randomized controlled trials were included to answer the following PICOS question: 'What grafting materials produce greater alveolar ridge preservation after tooth extraction?' The primary outcomes were the alveolar width resorption 1 mm below the alveolar crest and buccal height resorption in millimeters. Of the 4379 studies initially identified, 31 studies involving 1088 patients were included in the quantitative analyses. Out of 25 revised biomaterials, eight showed a statistically significant difference compared with unassisted healing in both alveolar width and height measurements (mean width differences: ApatosⓇ, 2.27 [1.266-3.28]; Bio-OssⓇ, 0.88 [0.33-1.42]; Bio-Oss CollⓇ, 0.53 [0.04-1.01]; Bond-apatiteⓇ, 2.20 [1.30-3.11]; freeze-dried bone allograft, 1.35 [0.44-2.26]; Gen-OsⓇ, 1.90 [0.60-3.20]; platelet-rich fibrin, 1.66 [0.66-2.67]; and MP3Ⓡ, 2.67 [1.59-3.75]). Overall, xenograft materials should be considered as among the best of the available grafting materials for alveolar preservation after tooth extraction.

Immediate single-tooth implant placement with simultaneous bone augmentation versus delayed implant placement after alveolar ridge preservation in bony defect sites in the esthetic region: A 5-year randomized controlled trial

BACKGROUND

It is unclear if an intact buccal bony plate is a prerequisite for immediate implant placement in post-extraction sockets. The aim of this 5-year randomized controlled trial was therefore comparison of peri-implant soft and hard tissue parameters, esthetic ratings, and patient-reported satisfaction of immediate implant placement in post-extraction sockets with buccal bony defects of ≥ 5 mm in the esthetic zone, with delayed implant placement after ridge preservation.

METHODS

Patients presenting a failing tooth in the esthetic region and a buccal bony defect of ≥ 5 mm after extraction were randomly assigned to immediate (Immediate group, n = 20) or delayed (Delayed group, n = 20) implant placement. Second-stage surgery and placement of a provisional restoration occurred 3 months after implant placement in both groups, followed by definitive restorations 3 months thereafter. The follow-up was 5 years. Marginal bone level (primary outcome), buccal bone thickness, soft tissue parameters, esthetics, and patient-reported satisfaction were recorded.

RESULTS

Mean marginal bone level change was -0.71 ± 0.35 mm and -0.54 ± 0.41 mm in respectively the Immediate group and the Delayed group after 5 years (P = 0.202). This difference, and in other variables, was not significant.

CONCLUSIONS

Marginal bone level changes, buccal bone thickness, clinical outcomes, esthetics, and patients' satisfaction following immediate implant placement, in combination with bone augmentation in post-extraction sockets with buccal bony defects of ≥ 5 mm, were comparable to those following delayed implant placement after ridge preservation in the esthetic zone.

Is ridge preservation effective in the extraction sockets of periodontally compromised teeth? A randomized controlled trial

OBJECTIVE

To verify whether ridge preservation is effective in the reduction of dimensional loss and in bone formation compared to spontaneous healing in extraction sockets of periodontally compromised teeth.

METHODS

Twenty-six subjects requiring tooth extraction for stage III/IV periodontitis were randomly assigned to one of two interventions: alveolar ridge preservation using collagenated bovine bone mineral and a resorbable collagen membrane (test, RP) or spontaneous healing (control, SH). Six months later, postoperative cone-beam computed tomography (CBCT) was performed to measure the linear and volumetric changes of the sockets compared to baseline scans. Biopsies were retrieved at the implant site for histomorphometric calculations. Nonparametric tests were applied for statistical analysis.

RESULTS

Significantly less shrinkage occurred in RP compared to SH, mainly in the crestal zone. The width loss difference between groups was 3.3 mm and 2.2 mm at 1 mm and 3 mm below the crest, respectively (p < .05). RP yielded a gain in socket height of 0.25 mm, whereas a loss of -0.39 mm was observed in SH (p < .05). The percentage of volume loss recorded in RP was also less than that recorded in SH (-26.53% vs -50.34, p < .05). Significantly less bone proportion was detected in biopsies from RP (30.1%) compared with SH (53.9%). A positive association between baseline bone loss and ridge shrinkage was found in SH but not in RP.

CONCLUSION

Ridge preservation in extraction sockets of periodontally compromised teeth was effective in reducing the amount of ridge resorption.

Immediate implant placement in fresh extraction sockets

Immediate implant placement (IIP) in fresh extraction sockets exhibits similar survival and success rates to delayed implant placement in healed sockets. Several advantages of IIP involve shortened total treatment time, reduction of the number of invasive surgeries, and subsequent reduction of patient discomfort due to lack of additional surgeries. The major shortcomings in IIP, however, include the inability to obtain early bony support, presence of a gap between the extraction socket and fixture, and the inability to cover the fixture with soft tissue, leading to increased risk of infection and implant loss. When IIP is performed, atraumatic or minimally traumatic extractions, conservation of the septal bone in molars, minimal flap elevation or flapless surgery, bone grafting the gap between the fixture and the extraction socket, and coverage with soft tissue or a membrane must be considered.

Prosthodontic Principles in Dental Implantology: Adjustments in a Coronavirus Disease-19 Pandemic-Battered Economy

More patients are requesting fixed prosthesis to replace missing teeth. More than 5 million dental implants are placed annually in the United States. This number will decrease in 2020 owing to the coronavirus disease-19 pandemic. The edentulous patient has a decreased quality of life. Prosthodontic rehabilitation/reconstruction of edentulism improves overall quality of life. Patient-reported outcome measures are subjective reports of patients' perceptions of their oral health status and the impact that it has on their quality of life. This chapter contains a variety of prosthodontic principles for the reader to help satisfy the needs and expectations of the patient.

Postextraction Ridge Width Alterations Following Socket Seal Surgery—A Retrospective Study

Background and objectives: Preservation of alveolar ridge contour following tooth extraction is important to allow for restoration with prosthetics and implants. Socket seal surgery was introduced more than two decades ago for preservation of the form, volume and bone quality of the postextraction ridge. The aim of this retrospective study was to assess the changes in alveolar ridge contour following socket seal surgery and to evaluate the survival of the soft tissue grafts sealing the extraction site. Materials and Methods: Digital images of the extraction sites treated with the socket seal surgery were obtained immediately after extraction and after a healing time of 6 months to measure the changes in the alveolar width. In addition, the sites were photographed 1 week postsurgery to evaluate the vitality of the soft tissue grafts. Results: The overall mean loss of buccal width following socket seal surgery was 5.3% (SD = 13.4%). The mean change in width at the incisor area (1.5% ± 13.1) was significantly lesser than those in the canine area (−17.0% ± 2.1, p < 0.01) or premolar area (−10.5% ± 11.2, p < 0.01). One-week post-surgery 69% of the grafts were vital, and 31% were partially vital. Complete necrosis of the grafts did not occur. Conclusions: Our results suggest that socket seal surgery has a beneficial effect on alveolar dimensional changes 6 months following tooth extraction and that the teeth that benefit mostly from socket seal surgery are incisors.

Bone marrow aspirate concentrate and platelet-rich fibrin in fresh extraction sockets: A histomorphometric and immunohistochemical study in humans

The aim of this study was to evaluate the level of mineralized tissue and expression of bone markers in sockets grafted with platelet-rich fibrin and bone marrow aspirate concentrate (BMAC). Patients requiring extraction of one maxillary anterior tooth were randomized into three groups. After tooth extraction, the sockets in the control group (CG) were permitted to fill with blood clot. In the platelet-rich fibrin group (PRFG), after blood processing, the sockets were grafted with PRF plug. In the bone marrow aspirate concentrate combined with platelet-rich fibrin group (BM/PG), after blood and bone marrow processing, the sockets were grafted with a mixture of PRF plug and BMAC. After 6 months, the sites were reopened and bone cores were harvested and prepared for histomorphometric and immunohistochemical evaluation. The following levels were measured: mineralized tissue, expression of RUNX-2, and osteocalcin. Fifteen patients were included in this study. The histomorphometric analysis showed a more pronounced level of mineralized tissue in PRFG and BM/PG (54.20 ± 4.31% and 64.70 ± 6.74%, respectively) when compared with CG (40.60 ± 5.98%) (p = 0.0283 and p = 0.0090, respectively). The expression of RUNX-2 was very low in BM/PG (0.80 ± 0.84%) and absent in CG and PRFG (p = 0.0528). Osteocalcin expression was higher for BM/PG (23.40 ± 1.52%) when compared with CG and PRFG (18.40 ± 2.07% and 16.20 ± 1.92%, respectively) (p = 0.0117 and p = 0.0088, respectively). This preliminary study indicates that clinical use of bone marrow aspirate concentrate, when combined with platelet-rich fibrin as a carrier, might have some potential to increase mineralization in fresh extraction sockets.

Immediate placement of single implants with or without immediate provisionalization in the maxillary aesthetic region: A 5-year comparative study

Aim

To compare marginal bone level changes around immediately placed and immediately provisionalized implants with immediately placed and delayed provisionalized implants in the aesthetic region after five years of function.

Materials and Methods

Forty patients with a failing tooth in the maxillary anterior region were randomly assigned immediate implant placement with immediate (Group A: n = 20) or delayed (Group B: n = 20) provisionalization. Definitive crown placement occurred three months after provisionalization. The primary outcomes were changes in marginal bone level. In addition, survival rates, buccal bone thickness, soft peri‐implant tissues, aesthetics and patient‐reported outcomes were assessed.

Results

After 5 years, the mean mesial and distal marginal bone level changes were 0.71 ± 0.68 mm and 0.71 ± 0.71 mm, respectively, in group A and 0.49 ± 0.52 mm and 0.54 ± 0.64 mm, respectively, in group B; the difference between the groups was not significant (p = .305 and p = .477, respectively). Implant and restoration survivals were 100%. No clinically relevant differences in buccal bone thickness or in mid‐facial peri‐implant mucosal level, aesthetic and patient outcomes were observed.

Conclusions

The mean marginal bone level changes following immediate implant placement and provisionalization were comparable with immediate implant placement and delayed provisionalization. (www.isrctn.com: ISRCTN57251089 and www.trialregister.nl: NL8255).

Immediate Implant Placement in Non-Infected Sockets versus Infected Sockets: a Systematic Review and Meta-Analysis

Objectives

The aim of this systematic review is to compare immediate implant placement in infected extraction sockets with non-infected extraction sockets in terms of implant survival and function.

Material and Methods

An electronic search was conducted in PubMed, ScienceDirect, ISI Web of Knowledge and Google Scholar between January 2010 and February 2020. Studies evaluating implant survival rate and main clinical parameters were included for a qualitative and quantitative analysis.

Results

In total, nine studies were included and a pool of 2281 sockets were analysed. Compared with the non-infected group, the infected group showed no significant differences in implant survival rates (risk ratio [RR] = 0.99; 95% confidence interval [CI] = 0.98 to 1; P = 0.08). No significant statistical differences were found in marginal bone level (mean difference [MD] = -0.03; 95% CI = -0.1 to 0.04; P = 0.41), marginal gingival level (MD = -0.07; 95% CI = -0.17 to 0.04; P = 0.23), probing depth (MD = 0.06; 95% CI = -0.24 to 0.36; P = 0.7), modified bleeding index (MD = -0.00162196; 95% CI = -0.09 to 0.09; P = 0.97) and slight but significant changes were seen in width of keratinized gingiva (MD = 0.25; 95% CI = -0.3 to 0.8; P = 0.38) between the groups at the latest follow-up.

Conclusions

There were no significant difference in implant survival rates, marginal bone level, marginal gingival level, modified bleeding index and probing depth between infected sockets and non-infected sockets. However, slight but significant changes were seen in width of keratinized gingiva favouring the non-infected group.

Mandibular dental implant placement immediately after teeth removal in head and neck cancer patients

BACKGROUND

Little is known about immediate implant placement in head and neck cancer patients. We studied implant survival and functional outcomes of overdentures fabricated on implants placed immediately after removal of the lower dentition during ablative surgery or preceding primary radiotherapy (RT).

METHODS

Inclusion criteria were primary head and neck cancer, dentate lower jaw, and indication for removal of remaining teeth. Two implants to support a mandibular overdenture were placed immediately after extraction of the dentition during ablative surgery, or prior to starting primary radiotherapy. Standardized questionnaires and clinical assessments were conducted (median follow-up 18.5 months, IQR 13.3).

RESULTS

Fifty-eight implants were placed in 29 patients. Four implants were lost (implant survival rate 93.1%). In 9 patients, no functional overdenture could be made. All patients were satisfied with their dentures.

CONCLUSIONS

Combining dental implant placement with removal of remaining teeth preceding head neck oncology treatment results in a favorable treatment outcome.

Tomographic and histomorphometric evaluation of socket healing after tooth extraction using leukocyte- and platelet-rich fibrin: A randomized, single-blind, controlled clinical trial

The use of platelet concentrate in alveolar ridge preservation has been broadly studied. However, no randomized clinical trials with histomorphometric analysis and low risk of bias are available in the literature. We conducted a prospective, single-blind, parallel, randomized, controlled clinical trial to evaluate the efficacy of leukocyte- and platelet-rich fibrin (L-PRF) in socket preservation after tooth extraction. Additionally, the effect of L-PRF on bone formation was analyzed histologically using bone biopsy specimens obtained during implant placement. A total of 48 subjects who underwent a non-molar tooth extraction were randomly assigned to the L-PRF group (n = 24) or the control group (n = 24). Cone-beam computed tomographies were performed immediately after tooth extraction and at 3 months after tooth extraction, prior to implant surgery. A significant difference in bone resorption was registered 1 mm below the crest: 0.93 ± 0.9 mm for the L-PRF group and 2.27 ± 1.2 mm for the control group (p = 0.0001). Histomorphometric analysis showed a higher percentage of new bone formation in the L-PRF group compared with the control group. The values were 55.96 ± 11.97% and 39.69 ± 11.13%, respectively (p = 0.00001). These findings indicate that the administration of L-PRF should always be considered when socket preservation is planned (Clinicaltrials.gov NCT03408418).