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The dynamics of tissue wound healing associated with dental implants placed in fresh extraction sockets or in healed alveolar ridges are not fully understood. Therefore, the aim of this preclinical in vivo investigation was to evaluate soft tissue healing and osseointegration after immediate implant placement, compared with delayed implant placement, using histomorphometric and immunohistochemical analyses. Methods: In 8 dogs, immediate postextraction implants and delayed implants were evaluated. After 2 and 8 weeks of healing, dissected tissue blocks were processed for calcified and decalcified histological analysis. Histometric measurements for soft tissue height and width were performed. Immunohistochemical analysis for the evaluation of bone metabolism, immune response and angiogenesis was performed. Results: At 2 weeks, histometric analysis showed that peri-implant soft tissue height was significantly greater in the immediate implant group (4.47 mm ± 0.78) compared to the delayed implant group (2.92 mm ± 0.51, p = 0.028), primarily due to the connective tissue height. Immunohistochemical analysis indicated significantly higher alkaline phosphatase (ALP) (6.85 ± 5.17 vs. 3.56 ± 2.31, p < 0.05) and matrix metalloproteinase (MMP2) activity (1.59 ± 1.64 vs. 0.58 ± 0.48, p < 0.05) in immediate implants, suggesting increased osteogenic and matrix metalloproteinase activity. At 8 weeks, the peri-implant soft tissue height remained higher in the immediate implant group (3.43 mm ± 0.83) compared to the delayed implant group (2.4 mm ± 0.37, p = 0.088), although the difference was less pronounced. Immunohistochemical differences between groups diminished in late healing stages. Conclusions: Soft tissue dimensions around immediate implants differ from those established around staged implants placed on healed alveolar ridges. Moreover, osseointegration dynamics around immediate implants may occur at a different rate compared with staged implants. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate osteogenic markers and alveolar ridge profile changes in guided bone regeneration (GBR) of chronic noncontained bone defects using a nonresorbable TiO2 block. Materials and Methods: Three buccal bone defects were created in each hemimandible of eight beagle dogs and allowed to heal for 8 weeks before GBR. Treatment was assigned by block randomization: TiO2 block: TiO2‐scaffold and a collagen membrane, DBBM particulates: Deproteinized bovine bone mineral (DBBM) and a collagen membrane, Empty control: Only collagen membrane. Bone regeneration was assessed on two different healing timepoints: early (4 weeks) and late healing (12 weeks) using several immunohistochemistry markers including alpha‐smooth muscle actin (α‐SMA), osteopontin, osteocalcin, tartrate‐resistant acid phosphatase, and collagen type I. Histomorphometry was performed on Movat Pentachrome‐stained and Von Kossa/Van Gieson‐stained sections. Stereolithographic (STL) models were used to compare alveolar profile changes. Results: The percentage of α‐SMA and osteopontin increased in TiO2 group after 12 weeks of healing at the bone‐scaffold interface, while collagen type I increased in the empty control group. In the defect area, α‐SMA decreased in the empty control group, while collagen type I increased in the DBBM group. All groups maintained alveolar profile from 4 to 12 weeks, but TiO2 group demonstrated the widest soft tissue contour profile. Conclusions: The present findings suggested contact osteogenesis when GBR is performed with a TiO2 block or DBBM particulates. The increase in osteopontin indicated a potential for bone formation beyond 12 weeks. The alveolar profile data indicated a sustained lateral increase in lateral bone augmentation using a TiO2 block and a collagen membrane, as compared with DBBM and a collagen membrane or a collagen membrane alone. [ABSTRACT FROM AUTHOR]

Root coverage in the anterior mandible is challenging due to a thin gingiva, shallow vestibule, and/or high frenulum. This case series reports on the flattening of the root surface to create a new emergence profile conceived with a two-step surgical approach aimed at providing more space for the graft, increasing the thickness of the gingival margin, and getting extra soft tissue in the open area of the recession. A total of 10 patients with recessions affecting the mandibular incisors were treated to evaluate this two-step approach, which included odontoplasty of the root followed by a connective tissue graft. At 1 year, the mean coverage was 100% in Class II recessions, and 80.5% in Class III. The mean keratinized tissue increase was 5.80 ± 1.75 mm. This surgical approach could be proposed as an alternative when treating mandibular anterior teeth with root prominence or with a buccally tilted position. [ABSTRACT FROM AUTHOR]

Purpose: To review the current literature to answer the focused question: in the experimental pig model (population), which types of peri-implant bone defects (exposure) have been used evaluate different modes of therapy and what is their capacity for spontaneous healing and regeneration (outcome)?, Methods: Following PRISMA guidelines, electronic databases were searched for studies reporting peri-implant bone defects in the maxillae or mandibles of pigs. Those studies which reported a control group of untreated defects with assessment of spontaneous regeneration [new bone area (BA)] and/or re-osseointegration [new bone-to-implant contact (BIC)] via quantitative radiography or histomorphometry were included in a random effects meta-analysis for the outcomes BA and BIC., Results: Overall, 21 studies, mostly performed in the mandibles of minipigs, were included. Most studies reported 'acute' intrabony (circumferential and/or dehiscence; n = 12) or supra-alveolar defects (horizontal; n = 4). Five studies attempted to induce 'chronic' peri-implantitis lesions using ligatures with conflicting results. Meta-analyses revealed pooled estimates (with 95% confidence intervals) of 48.07% BIC (30.14-66%) and 64.31% BA (42.71-85.91%) in intrabony defects, and 52.09% BIC (41.83-62.35%) and 28.62% BA (12.97-44.28%) in supra-alveolar defects. Heterogeneity in the meta-analysis was high (I 2  > 90%)., Conclusion: Current evidence for peri-implant bone regeneration in pigs is mainly based on acute intrabony defects, which demonstrate a high capacity for spontaneous regeneration and re-osseointegration. The evidence for chronic peri-implantitis is limited and does not clearly indicate a spontaneous progression of the disease in this animal model., Competing Interests: Declarations Consent for publication Not applicable. Competing interests The authors declare no competing interests. Ethical approval Not applicable. Registration The review was prospectively registered on PROSPERO: International Prospective Register of Systematic Reviews database (CRD42023450700)., (© 2024. The Author(s).)

Objectives: To evaluate osteogenic markers and alveolar ridge profile changes in guided bone regeneration (GBR) of chronic noncontained bone defects using a nonresorbable TiO 2 block., Materials and Methods: Three buccal bone defects were created in each hemimandible of eight beagle dogs and allowed to heal for 8 weeks before GBR. Treatment was assigned by block randomization: TiO 2 block: TiO 2 -scaffold and a collagen membrane, DBBM particulates: Deproteinized bovine bone mineral (DBBM) and a collagen membrane, Empty control: Only collagen membrane. Bone regeneration was assessed on two different healing timepoints: early (4 weeks) and late healing (12 weeks) using several immunohistochemistry markers including alpha-smooth muscle actin (α-SMA), osteopontin, osteocalcin, tartrate-resistant acid phosphatase, and collagen type I. Histomorphometry was performed on Movat Pentachrome-stained and Von Kossa/Van Gieson-stained sections. Stereolithographic (STL) models were used to compare alveolar profile changes., Results: The percentage of α-SMA and osteopontin increased in TiO 2 group after 12 weeks of healing at the bone-scaffold interface, while collagen type I increased in the empty control group. In the defect area, α-SMA decreased in the empty control group, while collagen type I increased in the DBBM group. All groups maintained alveolar profile from 4 to 12 weeks, but TiO 2 group demonstrated the widest soft tissue contour profile., Conclusions: The present findings suggested contact osteogenesis when GBR is performed with a TiO 2 block or DBBM particulates. The increase in osteopontin indicated a potential for bone formation beyond 12 weeks. The alveolar profile data indicated a sustained lateral increase in lateral bone augmentation using a TiO 2 block and a collagen membrane, as compared with DBBM and a collagen membrane or a collagen membrane alone., (© 2022 The Authors. Clinical Implant Dentistry and Related Research published by Wiley Periodicals LLC.)