Clinical and histological efficacy of a new implant surface in achieving early and stable osseointegration: An in vivo study.

An advantage of treated implant surfaces is their increased degree of hydrophilicity and wettability compared with untreated, machined, smooth surfaces that are hydrophobic. The present preclinical in vivo study aimed to compare the two implant surface types, namely SLActive (Straumann, Basel, Switzerland) and nanohydroxyapatite (Hiossen, Englewood Cliffs, NJ, USA), in achieving early osseointegration. The authors hypothesised that the nanohydroxyapatite surface is comparable to SLActive for early bone-implant contact. Six male mixed foxhounds underwent mandibular premolar and first molar extraction, and the sockets healed for 42 days. The mandibles were randomised to receive implants with either SLActive (control group) or nanohydroxyapatite surfaces (test group). A total of 36 implants were placed in 6 animals, and they were sacrificed at 2 weeks (2 animals), 4 weeks (2 animals) and 6 weeks (2 animals) after implant surgery. When radiographic analysis was performed, the difference in bone level between the two groups was statistically significant at 4 weeks (P = 0.024) and 6 weeks (P = 0.008), indicating that the crestal bone level was better maintained for the test group versus the control group. The bone-implant contact was also higher for the test group at 2 (P = 0.012) and 4 weeks (P = 0.011), indicating early osseointegration. In conclusion, this study underscored the potential of implants with nanohydroxyapatite surfaces to achieve early osseointegration.

Socket Preservation Following Tooth Extraction Using Polylactide-Polyglycolide Acid Scaffold: Radiologic and Histologic Evaluation.

PURPOSE: To assess the healing process of the extraction socket and the dimensional changes that occur after alveolar ridge preservation utilizing a polylactide-co-glycolide scaffold (PLGA). MATERIALS AND METHODS: The present study involved the extraction of 28 teeth from 14 patients. The total number of sockets was 28, which were divided into two groups consisting of 14 test sockets and 14 control sockets. The study group (SG) was subjected to socket preservation with a PLGA scaffold while the control group (CG) was left for spontaneous healing. The dimensions were measured before and after operation at 1, 3, and 5 mm below the alveolar crest horizontally and the height of buccolingual bone vertically. RESULTS: According to the histologic analyses, the PLGA scaffold was resorbed within 4 months. CBCT imaging revealed a decrease in the horizontal crest dimension at three distinct coronoapical levels in SG, measuring 2.05 ± 1.05 mm at -1 mm, 1.51 ± 0.89 mm at -3mm, and 0.92 ± 0.7 mm at-5mm.CG showed readings of 1.22 ± 1 at-1mm, 0.92 ± 0.67at-3mm, and 0.73 ± 0.69 at -5 mm. In comparison to CG, SG showed a significant reduction in horizontal losses at -1 mm. Vertical crest dimensions decreased by 1.64 ± 1.11 mm for the buccal bone height and by 1.56 ± 1.08 mm for lingual bone height in SG; in CG, the buccal and lingual bone height had mean values of 2.08 ± 1.44 mm and 1.73 ± 1.27 mm, respectively. There was no statistically significant difference observed in the vertical losses between the groups. CONCLUSIONS: Following a period of 4 months, the PLGA scaffold was completely resorbed. Based on CBCT measurements, horizontal resorption was lower than CG at -1 mm coronally.

Evaluation and comparison of autologous particulate dentin with demineralized freeze dried bone allograft in ridge preservation procedures - a prospective clinical study.

OBJECTIVES: To compare effectiveness of Autologous Particulate Dentin (APD) with Demineralized Freeze-Dried Bone Allograft (DFDBA) in ridge preservation, using radiographic and clinical parameters. MATERIALS AND METHODS: Thirty subjects with indication of mandibular posterior teeth extraction were randomly assigned to either test or control group. After atraumatic extraction, ridge preservation was performed using APD or DFDBA mixed with i-PRF in test and control groups respectively. Both groups had sockets sealed with A-PRF membrane. Clinical parameters (plaque, gingival and healing indices) and radiographic parameters (vertical ridge height, horizontal ridge width) were assessed at baseline and 6 months using CBCT. Statistical analysis was performed using an independent t-test to compare clinical and radiographic parameters between the groups. RESULTS: Both groups had significant decreases in ridge dimensions over 6 months (p < 0.001). The test group showed less reduction in ridge dimensions than control group at 6 months (p < 0.001). Mean change in vertical height was not significant (1.37 ± 1.32, 1.7311 ± 0.563), but in horizontal ridge width (1.3120 ± 1.13, 1.8093 ± 1.16) was significantly different between test and control groups respectively. There was no statistical difference in clinical parameters between the groups at 6 months (p > 0.001). CONCLUSIONS: APD grafts resulted in significant improvements in radiographic parameters, specifically in vertical ridge height and horizontal ridge width, compared to DFDBA group. CLINICAL RELEVANCE: Autologous particulate dentin is a promising, versatile substitute for regenerative procedures. While more research on its long-term efficacy and application is needed, current evidence suggests it could significantly improve patient care and outcomes.

Use of autologous tooth-derived material as a graft in the post-extraction socket. Split-mouth study with radiological and histological analysis.

BACKGROUND: The healing process after tooth removal involves bone remodelling which implies some loss of alveolar bone volume. Among materials proposed for minimising this remodelling and preserving the bone, autologous dental tissue is a promising option, but more data are needed. In this context, we evaluated size and density changes using cone beam computed tomography in autologous dental material (ADM)-preserved sockets compared to controls, and assessed biological responses by histological analysis. METHODS: A split-mouth study was conducted including 22 patients, who underwent removal of ≥ 2 single-rooted teeth with intact sockets, assigning one socket to the experimental group which received ADM for alveolar preservation and another to the control group, which only underwent blood clot stabilisation. Cone beam computed tomography was performed postoperatively (week 0) and at weeks 8 and 16 to assess socket size and bone density. Histological analysis was carried out on trephine biopsies taken (Ø4 × 4.5 mm) from the experimental group. RESULTS: Less horizontal shrinkage was observed in the ADM group, especially at week 16 considering the group-by-time interaction for the following variables: difference in height between the lingual and buccal alveolar crests (-1.00; p < .01; 95% CI: -0.28 - -1.73), and half-widths, measured as the distance from the long axis of the missing tooth to the buccal alveolar crest at 1 mm (-0.61; p < .01; 95% CI: -0.18 - -1.04) and at 3 mm (-0.56; p < .01; 95% CI: -0.15 - -0.97) below the crest, with mean decreases of 1.07 and 2.14 mm in height difference, 0.66 and 1.32 mm in half-width at 1 mm and 0.43 and 1.02 mm in half-width at 3 mm in ADM and control groups respectively. Densitometry analysis showed higher bone densities in Hounsfield units in the ADM group considering all factors analysed regardless of time point and socket third (coronal, middle, or apical). Histologically, there were no signs of inflammation or foreign body reaction, and dentin particles were surrounded by and in close contact with bone tissue. CONCLUSION: These results add to the evidence that dentin can be used successfully as a material for alveolar socket preservation, given its desirable mechanical and biological properties, and warrant larger studies.

Clinical and radiographic outcomes of a two-piece ceramic implant: one year results from a prospective clinical trial.

OBJECTIVE: To describe the clinical and radiographic performance and survival rate of a new two-piece ceramic implant system after at least 12 months of follow-up. MATERIALS AND METHODS: Sixty-five implants were placed and followed up for at least 12 months (12.3 ± 1.5), in 50 patients. The implants were installed both in fresh extraction sockets and in healed sites and received provisional restoration when the clinical insertion torque was greater than 35Ncm. The primary results describe the survival rate of these implants. Clinical performance was evaluated through the evaluation of the Pink Esthetic Score (PES) and the degree of satisfaction of the patients. Bone loss was measured through radiographic measurements of the marginal bone loss in the mesial (MBLM) and distal (MBLD) sites. RESULTS: The survival rate was 98.5%. The average MBLM was 0.24 mm (± 0.53) and the MBLD was 0.27 mm (± 0.57). A statistical difference was observed only when comparing immediate implants with delayed ones (MBLM - p = 0.046 and MBLD - p = 0.028) and when they received immediate provisionalization or not (MBLM - p = 0.009 and MBLD - p = 0.040). The PES before the intervention (T0) was 13.4 (± 0.8) and the PES at T2 (12-month follow-up) was 12.9 (± 1.5) (p = 1.14). CONCLUSION: The new two-piece ceramic implant used in the present study showed predictable and reliable results, similar to those found with titanium implants after one year of follow-up. CLINICAL RELEVANCE: These implants can be used as an alternative to titanium implants in terms of the marginal bone loss and the degree of patient satisfaction.

Effect of Sagittal Root Position, Angle, and Bone Thickness on Peri-implant Tissue Phenotype and Bone Level in Socket Shield Technique: A Retrospective Case Series.

There were only a few studies investigating the effect of sagittal root position (SRP), sagittal root angle (SRA), and buccal bone thickness (BBT) on peri-implant tissues using the socket shield technique (SST). This retrospective case series aimed to evaluate the SRP, SRA, and BBT in socket shield cases and examine the effect of these anatomical factors on the peri-implant tissue phenotype and bone level. Data from 27 patients (14 women, 13 men) treated with SST in the maxillary esthetic region between July 2019 and September 2021 were included. Clinical indices (modified plaque and bleeding indices, probing depth, keratinized mucosa width, mucosal thickness) and periapical radiographic recordings (marginal bone level) taken immediately after permanent prosthesis placement and 1 year later were used. Cone beam computerized tomography images were used to examine BBT, SRP, and SRA before implant placement and horizontal and vertical bone levels before implant placement and 1 year after prosthetic rehabilitation. The data were divided into groups based on BBT (<1 and ≥1 mm) and SRA values (<10° and ≥10°). There were no significant differences in 1-year clinical factors between the SRA <10° and SRA ≥10° groups. However, higher vertical bone loss was found in the SRA ≥10° group (P = .01, d = 0.53). There were no significant differences in clinical or radiographic factors between the BBT <1 mm and BBT ≥1 mm groups. In conclusion, BBT showed no significant effect on tissue phenotype and bone level, but SRA affected bone level in socket shield cases.

Influence of freeze-dried bone allograft on free gingival graft survival and alveolar ridge maintenance in socket seal procedures: a randomized controlled clinical trial.

PURPOSE: This study aimed to investigate the viability of free gingival grafts (FGG) and assess clinical and radiographic changes in the alveolar ridge following socket seal surgery with or without freeze-dried bone allograft (FDBA). MATERIALS AND METHODS: Twenty-eight anterior and premolar tooth extractions were randomly allocated to 2 groups: socket graft of FDBA sealed with FGG (n = 15) and control with empty sockets sealed solely with FGG (n = 13). Photographs taken at 3, 7, 14, and 30 days post-surgery assessed FGG viability. Alveolar ridge volume was clinically evaluated via intraoral scanners before surgery and at 1 and 3 months post-surgery. CBCT scans taken immediately post-surgery and 3 months later assessed alveolar ridge dimensions. RESULTS: FGG viability in both groups increased from day 3 and reached the maximum score on day 14. Alveolar ridge volume reduction at 3 months in the FDBA group was comparable to the control group. Buccal alveolar bone height reduction was significantly higher in the FDBA group than the control group, while palatal alveolar bone height was comparable. Alveolar bone width reduction was evident but not statistically significant between the groups. The FDBA group exhibited a significant alteration in bone volume compared to the control group. CONCLUSION: Viability of FGG was not affected by graft filling materials. Sealing the socket with FGG effectively preserved socket integrity and ridge volume in minor socket defects using either graft filling material or not. This study was registered on 4 January 2021 on Thai Clinical Trials Registry (TCTR20210104001).

Synchrotron Analysis of Damaged Extraction Sockets Augmented Using a Synthetic Bone Block: A Pilot Study.

This study aimed to investigate the dimensional stability and quality of the alveolar ridge augmented using a synthetic bone block (SBB) at damaged extraction sockets. Four participants were included, and socket augmentation was performed using SBB and a collagen membrane. Intraoral and CBCT scans were performed before extraction (baseline), immediately postoperative (IP), and at 6 months postoperative (6M). At 6M, a trephine biopsy sample was obtained during implant placement, and the sample was observed using synchrotron. Soft tissue profile changes were assessed using profilometric analysis of the intraoral scan data, while dimensional changes in hard tissue were evaluated based on CBCT measurements. Bone quality was analyzed using synchrotron imaging. There were minimal changes in the soft tissue profile between baseline and IP, baseline and 6M, and IP and 6M (0.11 ± 1.08 mm3, 0.02 ± 0.8 mm3, and -0.65 ± 0.82 mm3, respectively). Horizontal bone width was measured at 1-mm increments from the augmented bone crest to 5 mm apically and revealed only a slight reduction (< 1 mm) at all levels between IP and 6M. The augmented bone height was well maintained from IP until 6M (-0.21 ± 0.53 mm). Synchrotron analysis revealed low to moderate bone quality after 6M (percentage of new bone: 16.49% ± 4.91%). Socket augmentation using SBB appears to be a viable technique for regenerating damaged extraction sockets, with the augmented ridge dimensions maintained up to 6M. Further long-term randomized clinical trials are needed.

The adjunctive effect of polydeoxyribonucleotide on bone formation in alveolar ridge preservation: A pre-clinical in vivo study.

AIM: This study investigated the adjunctive effect of polydeoxyribonucleotide (PDRN) on bone formation in alveolar ridge preservation (ARP) sockets. MATERIALS AND METHODS: Both mandibular second, third and fourth premolars of eight beagle dogs were randomly divided into ARP and ARP/PDRN groups. Following tooth extraction, ARP procedures were conducted using collagenized alloplastic graft material and bilayer collagen membrane soaked with normal saline (ARP group) or PDRN (ARP/PDRN group) for 10 min before application. Both groups were also randomly allocated to 2-, 4- or 12-week healing subgroups. The primary endpoint of this study was to compare histomorphometric differences between ARP and ARP/PDRN. The secondary endpoints of this study were to compare micro-CT analysis and three-dimensional volumetric measurement between the two groups. RESULTS: In the histomorphometric analysis, the ARP/PDRN group exhibited greater new bone formation at coronal, middle and total position compared with the ARP group at 2-week healing. The number of newly formed blood vessels was higher in the ARP/PDRN group than in the ARP group at 2- and 4-week healing. In micro-CT analysis, the mean new bone volume/total bone volume between ARP and ARP/PDRN was statistically significant at 2-week healing. Ridge volume alterations were significantly decreased in the ARP/PDRN group during entire healing time compared with the ARP group, especially on the buccal side. CONCLUSIONS: The application of PDRN in ARP might provide additional benefits for early bone regeneration and maintenance of buccal ridge volume.

A radiographic and histological study to compare red (650 nm) versus near infrared (810 nm) diode lasers photobiomodulation for alveolar socket preservation.

Previous findings indicated that the laser photobiomodulation is more effective than the control or placebo in preserving the alveolar socket. This study aimed to compare two different lasers regarding their effectiveness in aiding alveolar socket preservation. Twenty extraction sockets were selected then divided into two equal groups. Group A was exposed to 650 nm Diode laser, and Group B to 810 nm Diode laser following the same protocol and parameters after a standard alveolar socket preservation procedure with collagen plug. Radiographic analysis with cone beam computed tomography was done to compare the alveolar bone surface area immediately after extraction and three months post-operatively, while bone samples collected before implant drilling were histologically examined for newly formed bone evaluation and histomorphometric analysis in terms of percentage of new bone surface area, percentage of unmineralized bone and finally, immunohistochemical analysis of Osteocalcin reaction surface area as well as optical density. Radiographically, infrared (810 nm) Diode effect on alveolar bone surface area has significantly exceeded the red laser, while histologically, red (650 nm) Diode has demonstrated statistical significance regarding all parameters; newly formed bone surface area percentage, unmineralized bone area percentage and finally Osteocalcin bone marker reaction surface area percentage and optical density. Under the specified conditions and laser parameters, photobiomodulation using the 810 nm Diode got the upper hand radiographically, yet histologically, the red 650 nm Diode managed to dominate all histological parameters when both employed as an adjunct to alveolar socket preservation procedures.

Regeneration of alveolar bone defects in the experimental pig model: A systematic review and meta-analysis.

OBJECTIVE: Pigs are emerging as a preferred experimental in vivo model for bone regeneration. The study objective was to answer the focused PEO question: in the pig model (P), what is the capacity of experimental alveolar bone defects (E) for spontaneous regeneration in terms of new bone formation (O)? METHODS: Following PRISMA guidelines, electronic databases were searched for studies reporting experimental bone defects or extraction socket healing in the maxillae or mandibles of pigs. The main inclusion criteria were the presence of a control group of untreated defects/sockets and the assessment of regeneration via 3D tomography [radiographic defect fill (RDF)] or 2D histomorphometry [new bone formation (NBF)]. Random effects meta-analyses were performed for the outcomes RDF and NBF. RESULTS: Overall, 45 studies were included reporting on alveolar bone defects or extraction sockets, most frequently in the mandibles of minipigs. Based on morphology, defects were broadly classified as 'box-defects' (BD) or 'cylinder-defects' (CD) with a wide range of healing times (10 days to 52 weeks). Meta-analyses revealed pooled estimates (with 95% confidence intervals) of 50% RDF (36.87%-63.15%) and 43.74% NBF (30.47%-57%) in BD, and 44% RDF (16.48%-71.61%) and 39.67% NBF (31.53%-47.81%) in CD, which were similar to estimates of socket-healing [48.74% RDF (40.35%-57.13%) and 38.73% NBF (28.57%-48.89%)]. Heterogeneity in the meta-analysis was high (I2 > 90%). CONCLUSION: A substantial body of literature revealed a high capacity for spontaneous regeneration in experimental alveolar bone defects of (mini)pigs, which should be considered in future studies of bone regeneration in this animal model.

Alveolar Ridge Preservation Using the One-Piece Autologous Tuberosity Graft: A Clinical, Radiological, and Histological Pilot Study.

This prospective study investigated clinically and radiologically the effectiveness of the use of a combined hard and soft tissue graft retrieved from the maxillary tuberosity and designed for alveolar ridge preservation following tooth extraction. Seven patients scheduled for a single mono-rooted tooth extraction were included in the study. After atraumatic extraction, sockets were filled with a "one-piece" dual tissue graft harvested from the tuberosity using an adjusted trephine. CBCTs were performed before the extraction and 4 months after ridge preservation, to analyze the vertical and horizontal alterations of the ridge, using ITK-Snap software. Clinical measurements of both soft and hard tissues were also assessed during the extraction and implant placement. All sites healed uneventfully. After 4 months, the 3D super-imposition of both CBCTs showed a mean bone volume resorption of 65 ± 76.7 mm3 (10.2 ± 10%). The mean horizontal reduction at 2, 4, and 6 mm from the top of the crest was respectively 1.5 ± 1.3 mm, 0.47 ± 1.4 mm and 0.57 ± 0.7 mm, while the mean vertical loss was 0.026 mm ± 2 mm. The mean soft tissue horizontal gain was 1.73 ± 1.12 mm. The "one-piece" autologous tuberosity graft was proven to be a safe and effective alveolar ridge preservation technique and may represent a feasible, user-friendly, time saving, low-cost solution for minimizing dimensional loss following tooth extraction.

Five-Year Clinical, Radiographic, and Cone-Beam Follow-Up of Socket Shield Technique in Two Cases Treated with a Split Mouth Design.

The two presented cases of socket shield technique were done following a split mouth protocol in two patients, each received an immediate implant inserted conventionally on maxillary one side and another implant inserted applying the socket shield technique on the contralateral side. The outcomes including soft and hard tissue changes were compared clinically and radiographically. The four implants were followed for 5 years, and the outcomes were successful.

Clinical and radiographic outcomes of implants placed in extraction sites treated with alveolar ridge preservation: a 10-year retrospective analysis of a case series.

OBJECTIVES: The aim of the present study was to evaluate clinical and radiographic outcomes of implants placed in alveolar sockets treated by means of alveolar ridge preservation after 10 years of follow-up. METHOD AND MATERIALS: Eleven patients treated with 11 implants placed after alveolar ridge preservation using bovine-derived xenograft particles and collagen membrane were selected. Full-mouth plaque score, full-mouth bleeding score, probing depth at four sites per implant, and radiographic marginal bone level at mesial and distal aspects for each implant were recorded at baseline and after 10 years of follow-up. The primary outcome was the radiographic marginal bone loss. The marginal bone loss was considered as the difference between marginal bone level at baseline and after 10 years of observation time. RESULTS: After 10 years of follow-up, full-mouth plaque score increased significantly (P < .05), while no statistically significant differences were found in the change in full-mouth bleeding score (P ≥ .05). At the 10-year observation period, a significant increase in probing depth was observed at all sites (P < .05), except at the mesial aspects (P ≥ .05). Radiographic marginal bone loss was 1.1 ± 0.1 mm and 1.0 ± 0.1 mm at mesial and distal sites, respectively. CONCLUSION: Whitin the limitations of the present study, implants placed in post-extraction sockets treated with alveolar ridge preservation yielded stable clinical and radiographic results after 10 years of follow-up.

The facial-coronal ridge crest alterations after single immediate implant placement and provisionalization with thin buccal plate phenotype in anterior maxilla: A radiographic case-series study.

AIM: To explore the features of and potential landmarks that predict crestal ridge remodeling after immediate implant placement and provisionalization (IIPP) with thin buccal plate phenotype in the anterior maxilla. MATERIALS AND METHODS: Patients requiring IIPP of single maxillary incisor with thin buccal bone plate (<1 mm) were recruited. Cone-beam computed tomography (CBCT), performed before and 6 months after the intervention, were three-dimensionally superimposed. A virtual line connecting the bony emergence points of adjacent teeth was drawn as a reference. The facial-coronal alveolar crest of the extraction socket and healed ridge were located in mesial, middle and distal cross-sectional planes, and linear ridge reductions were measured. The correlation between ridge reduction and local factors was analyzed. RESULTS: Fifty patients were included. From the extraction socket to healed ridge, the alveolar crest underwent linear bone reduction of 1.50 ± 0.50, 1.54 ± 0.66 and 1.65 ± 0.73 mm in the mesial, middle, and distal regions in an apical-palatal direction. The middle region had significantly higher horizontal (facial-palatal) but lower vertical (coronal-apical) bone reduction than the mesial and distal areas (P < 0.01). The facial-coronal ridge crest of the healed ridge located close to the reference line. Ridge reduction positively correlated with the distance between the initial facial-coronal crest of the extraction socket and the reference line (P < 0.01). CONCLUSIONS: Alveolar crest of the socket lost its curvature and tended to attain a flat profile after IIPP due to inconsistent ridge reduction in middle, mesial and distal areas. The reference line may be a potential landmark for predicting the ridge crest after remodeling.

Immediate Implant Placement Using the Socket Shield Technique: Clinical, Radiographic, and Volumetric Results Using 3D Digital Techniques-A Case Series.

Extraction-site alveolar remodeling is a major concern due to negative volumetric hard and soft tissue changes that inevitably limit rehabilitation options and diminish esthetic outcomes. Surgical techniques employed to minimize alveolar dimensional changes are not always predictable. Utilizing a socket shield with an immediate surgical implant procedure helps maintain a thin portion of the root in the vestibular area and thus minimizes bone resorption, especially at the coronal cortical aspect. This case series assesses the dimensional changes in peri-alveolar structures via superimposition of the preoperative and 6-month postoperative 3D digital quantification of soft tissue. Fifty patients with 50 sites fulfilled the inclusion criteria. Implant survival was 100%, with no incidence of complications. Tissue changes were as follows: -0.85 mm at the mesial papilla, -0.95 mm at the distal papilla, -0.7 mm at both the vertical and horizontal central margins, -0.21 mm at a distance 4 mm from the margin, and -0.64 mm at the palatal central margin. The buccal contour was clinically convex in all cases. The site with highest frequency of > 1 mm of dimensional loss was the distal papilla (42% of sites), and the site with the lowest frequency was the point 4 mm from the midfacial margin (0% of sites).

Alveolar ridge changes 1-year after early implant placement, with or without alveolar ridge preservation at single-implant sites in the aesthetic region: A secondary analysis of radiographic and profilometric outcomes from a randomized controlled trial.

OBJECTIVES: To assess both the radiographic and profilometric outcomes of early implant placement with or without alveolar ridge preservation (ARP) (using two different ARP techniques) after 1 year of loading. MATERIALS AND METHODS: Seventy-five patients with a failing single tooth in the anterior maxilla were randomly allocated to three groups (1:1:1): (a) ARP using demineralized bovine bone mineral containing 10% collagen (DBBM-C) covered by a collagen matrix (CM), (b) ARP using DBBM-C covered with a palatal graft (PG), and (c) unassisted socket healing (control). Eight weeks after tooth extraction, early implant placement was performed in all patients. Cone-beam computed tomography (CBCT) and impressions were taken 8 weeks after tooth extraction (ARP/unassisted healing) prior to implant placement and 1-year post-loading. Radiographic and profilometric outcomes were evaluated. RESULTS: Out of the 70 patients available for re-examination at 1-year post-loading, 55 datasets could be assessed (ARP-CM 19; ARP-PG 17; Control 19). The need for additional guided bone regeneration (GBR) at implant placement amounted to 31.6% (ARP-CM), 29.4% (ARP-PG), and 68.4% (unassisted healing). Adjusted models revealed that residual buccal bone height and additional GBR at implant placement significantly influenced the magnitude of the alveolar changes at 1 year (p < 0.05). In patients with ARP (group ARP-CM or ARP-PG) without additional GBR, the presence of bone convexity amounted to 36.0% (9/25) at 1-year post-loading. For patients that received ARP and additional GBR at implant placement, the frequency of bone convexity increased to 72.7% (8/11) (p = 0.042). Regarding profilometric measurements, a tendency toward agreement with radiographic outcomes was observed. CONCLUSIONS: Early implant placement with ARP can attenuate alveolar ridge changes at 1-year post loading by minimizing both radiographic and profilometric alterations. However, early implant placement with simultaneous GBR consistently yields superior radiographic and profilometric outcomes, regardless of whether ARP is performed.

The impact of immediate versus delayed mini-screw placement on alveolar bone preservation and bone density following tooth extraction: evidence from a canine model.

The aim of this study was to evaluate the impact of mini-screw placement on the alveolar ridge using a split-mouth design. Twelve beagles underwent bilateral extraction of their lateral teeth. In the immediate group, a mini-screw was unilaterally placed approximately 3-4 mm below the alveolar crest of the extraction site on the experimental side. The delayed group received mini-screws six weeks after tooth extraction. On average, the dogs were sacrificed after 11 weeks, and the maxillary bones were excised and scanned using cone-beam computed tomography (CBCT). Histopathological examinations were conducted to assess inflammation and bone formation scores. The results showed that in the immediate group, bone height was significantly greater on the intervention side compared to the control side (p < 0.05), whereas there was no significant difference in the delayed group. In both groups, there was a significant increase in bone density around the mini-screws compared to the control sides (p < 0.05). Mini-screw insertion led to a significant enhancement of bone growth in both groups (p < 0.05), with no notable differences between the two groups. The mini-screws did not have any impact on bone inflammation or width. Overall, both immediate and delayed mini-screw placement in the extraction socket positively influenced bone dimensions, density, and histological properties. However, immediate insertion was more effective than delayed placement in preserving vertical bone height, despite delayed insertion resulting in higher bone density.

Radiographic comparison of atelocollagen versus deproteinized bovine bone minerals covered with a collagen membrane in alveolar ridge preservation: a retrospective study.

BACKGROUND: Atelocollagen (AC) is a low-immunogenic collagen derivative with longer degradation time, which can be a suitable material for alveolar ridge preservation (ARP). However, there are few human studies on AC using for ARP. This research aims to radiographically evaluate the efficacy of AC in comparison to deproteinized bovine bone minerals covered with a collagen membrane (DBBM/CM) in ARP. METHODS: Medical records in the Implantology Department of the Hospital of Stomatology of Wuhan University were screened for patients who received flapless ARP using either AC or DBBM/CM. A total of 58 patients were included in this retrospective study. 28 patients were treated with AC, while 30 patients were used DBBM/CM. Cone-beam computed tomography (CBCT) scans were taken before extraction and after 6 months of healing. To assess the dimensional change of the extraction sockets, the scanning data were output and transferred to the digital software to measure horizontal bone width change, vertical bone height change and bone volume change in region of interest. To evaluate the bone quality of healed sockets, the bone density of virtual implants was evaluated. RESULTS: The horizontal bone width changes at all five different levels showed no significant difference between the two groups. The largest horizontal bone width decrement in both groups occurred at the crest of ridge, which decreased 3.71 ± 1.67 mm in AC group and 3.53 ± 1.51 mm in DBBM/CM group (p = 0.68). At the central buccal aspect, the ridge height reduced 0.10 ± 1.30 mm in AC group, while increased 0.77 ± 2.43 mm in DBBM/CM group (p = 0.10). The vertical bone height differences between two groups showed no statistical significance. The percentages of volume absorption in AC group and DBBM/CM group were 12.37%±6.09% and 14.54%±11.21%, respectively. No significant difference in volume absorption was found (p = 0.36). The average bone density around virtual implants in AC group (649.41 ± 184.71 HU) was significantly lower than that in DBBM/CM group (985.23 ± 207.85 HU) (p < 0.001). CONCLUSIONS: ARP with AC had a similar effect on limiting the dimensional alteration of alveolar ridge, when radiographically compared with DBBM/CM.

Mixing Allograft and Xenograft for a Predictable Alveolar Ridge Preservation Procedure: A Case Series.

BACKGROUND: An alveolar ridge preservation (ARP) procedure is commonly performed to preserve ridge width and height for optimal dental implant placement. Mixing different sources of bone grafts may help maximize their properties to obtain predictable ARP results. OBJECTIVE: The aim of this case series is to highlight the clinical and radiographic outcomes of a combined allograft and xenograft approach for a predictable ARP procedure. MATERIALS AND METHODS: Eleven clinical cases that required tooth extraction and future implant placement were selected for this case series. All surgeries were performed by a single clinician in a private practice setting. All cases underwent an ARP procedure, which included atraumatic extraction, degranulation, assessment of the socket, and the use of a combination of allograft and xenograft fibers/granules in a 1:1 mixing approach. Based on the socket defect, either a type I or type III collagen membrane was used during the procedure. In all cases CBCT imaging was done prior to surgical implant placement, and digital implant planning was performed integrating interdisciplinary best practices. Implant placement was carried out using manufacturer's recommendations. RESULTS: Five male and five female patients were included in the study, with one of the male patients having two teeth extracted for a total of 11 cases. The reasons for teeth extraction included fracture, endodontic failure, periodontal infection, and subgingival decay. Healing was uneventful after the ARP procedure for all patients. A minimum of 120 days elapsed between ARP and the surgical implant procedure. Complete radiographic bone fill was observed in the CBCT image for all extraction sites, and no additional bone augmentation was needed at the time of implant placement. CONCLUSION: This case series demonstrates that based on clinical and radiographic outcomes, a combination of allogenic and xenogenic bone substitute can be utilized to obtain predictable results following ARP. Future randomized controlled trials that can compare different ratios between the two biomaterials are indicated to guide clinicians in the mixing protocols and their outcomes.