Holland et al. [9] 2003 (Brazil) | Neoformed cementum in all specimens, with an average thickness of 83 µm. In most cases, the newly formed cementum repaired the areas of resorption and produced closure of the main canal (10 cases). Complete biological closure of all accessory canals was observed in only 4 cases. The average thickness of periodontal ligament was 302 µm. The inflammatory reaction was absent in only two specimens. Gram-negative and Gram-positive microorganisms were present in all but 3 specimens. | 07 days: Neoformed cementum was observed in all cases, with a mean thickness of 93 µm. The newly formed cementum repaired areas of resorption in almost all cases, and completely sealed the main root canal in 16 specimens. The periodontal ligament was well organized in 05 cases, and there was a partial organization in the other specimens. The average thickness of the apical periodontal ligament was 264 µm. In six cases there were no inflammatory cells. Gram-positive and Gram-negative microorganisms were found in 10 cases in some apical accessory root canals and cementum gaps. 14 days: Neoformed eosinophilic cementum with a mean thickness of 91 µm was observed in all specimens. This cementum repaired areas of resorption in all but two cases. There was complete closure of the main canal in 14 specimens. The periodontal ligament was well organized in three cases and partially organized in the other specimens. The apical ligament had a mean thickness of 298 µm and showed an inflammatory reaction in seven cases and no inflammation in nine specimens. The Brown and Brenn technique showed Gram-positive microorganisms in four cases and only in some gaps in the apical cementum. |
Machado et al. [20] 2009 (Brazil) | 30 days: All specimens in this subgroup showed intense acute and chronic inflammatory infiltrate, with the presence of neutrophils, macrophages, and plasma cells. 90 days: Persistence of the inflammatory condition present at 30 days was observed in all specimens. There were areas of cement resorption filled with intense inflammatory infiltrate and cementoclasts and reabsorbing hard tissue. | Neoformation of cementum and/or bone tissue was observed in six roots (three at 30 days and three at 90 days). Areas of resorption associated with neoformation processes were also visualized. Neoformed blood vessels could also be observed. Acute inflammatory infiltrate could be found in two specimens, whereas chronic inflammatory infiltrate occurred in eight specimens. |
Silveira et al. [21] 2007 (Brazil) | Success rate of 46% (6 of 13 cases). Histobacteriological analysis revealed that the majority of cases in this group still harbored bacteria on the root canal walls and sometimes within the dentinal tubules. Bacterial cells were also observed in the apical region. Scores: 0 = 31%, 1 = 15%, 2 = 15%, 3 = 39% | Periradicular tissues free of inflammation or with mild inflammation. Areas of root resorption were usually covered by cementum, indicating that these areas had been repaired and resorption had ceased. The vast majority of root canals were free of bacteria. Success rate of 74% (11 of 15 cases). Scores: 0 = 27%, 1 = 47%, 2 = 20%, 3 = 7% |
Leonardo et al. [22] 2006 (Brazil) | Inflammatory infiltrate - Absent: 0, Slight: 2, Moderate: 4, Severe: 0 / Periodontal ligament space - Normal: 0, Slightly increased: 3, Moderately increased: 3, Severely increased: 10/ Dentin resorption - Absent: 14, Present: 2/ Cementum resorption - Absent: 4, Present: 12/ Bone resorption - Absent: 0, Present: 16 | 15 days: Inflammatory infiltrate - Absent: 0, Slight: 12, Moderate: 4, Severe: 1/ Periodontal ligament space - Normal: 0, Slightly increased: 4, Moderately increased: 10, Severely increased: 3/ Dentin resorption- Absent: 17, Present: 0/Cementum resorption - Absent: 14, Present: 3 /Bone resorption - Absent: 16, Present: 1. 30 days: Inflammatory infiltrate- Absent: 0, Slight: 14, Moderate: 2, Severe: 1/ Periodontal ligament space - Normal: 1, Slightly increased: 6, Moderately increased: 8, Severely increased: 2/ Dentin resorption - Absent 17, Present: 0/ Cementum resorption - Absent: 15, Present: 2/ Bone resorption - Absent: 15, Present: 2. 180 days: Inflammatory infiltrate - Absent: 0, Slight: 13, Moderate: 3, Severe: 0/ Periodontal ligament space - Normal: 0, Slightly increased: 9, Moderately increased: 7, Severely increased: 0/ Dentin resorption - Absent: 16, Present: 0/ Cementum resorption- Absent: 15, Present: 1/ Bone resorption - Absent: 15, Present: 1 |
Paula-Silva et al. [23] 2009 (Brazil) | Extension of the inflammatory reaction - Absent: 0, Restricted to the apical foramen: 0, Up to half of the apical periodontal ligament: 4 (22.2%), Beyond half of the periodontal ligament: 14 (77.8%) / Tooth resorption - Absent: 3 (16.7%), Cementum resorption − 12 (66.6%), Dentin resorption − 3 (16.7%) / Apical opening sealed with mineralized tissue - Complete sealing: 1 (5.5%), Sealing beyond half: 2 (11.1%), Sealing up to half: 0, Absence of sealing: 15 (83.4%). | Extension of the inflammatory reaction - Absent: 0, Restricted to the apical foramen: 7 (33.3%), Up to half of the apical periodontal ligament: 8 (38.1%), Beyond half of the periodontal ligament: 6 (28,6%) / Tooth resorption - Absent: 9 (42,9%), Cementum resorption − 12 (57.1%), Dentin resorption − 0/ Apical opening sealed with mineralized tissue - Complete sealing: 15 (71.4%), Sealing beyond half: 2 (9.5%), Sealing up to half: 0, Absence of sealing: 4 (19.1%). |
De Rossi et al. [24] 2005 (Brazil) | 30, 75 and, 120 days: Periapical lesion and inflammatory infiltrate composed of neutrophils, histiocytes, xanthomatous histiocytes, plasma cells, and lymphocytes, and marked edema. Surface resorption areas (Howship’s lacunae) were evident, similar to those seen on the cementum surface. | 30 and 75 days: Two different patterns: one mainly showing scarring repair tissue characterized by proliferation of fibroblasts, small vessels, and increased connective tissue, and the other showing an inflammatory infiltrate similar to that of teeth filled in one-visit. 120 days: Marked reduction in the size of the periapical alterations. |
Paula-Silva et al. [25] 2010 (Brazil) | Mean (standard deviation) - Inflammatory infiltrate - Polymorphonuclear: 9.6 (± 6.6); Mononuclear: 59.5 (± 9.1); Fibroblast: 30.9 (± 4.4); Inflammatory activity index − 2.31. Presence of bacteria: 83.3% | Mean (standard deviation) - Inflammatory infiltrate - Polymorphonuclear: 4.3 (± 3.2); Mononuclear: 48.7 (± 9.5); Fibroblast: 46.9 (± 11.2); Inflammatory activity index: 1.23. Presence of bacteria: 42.8% |
Tanomaru et al. [26] 2002 (Brazil) | Group I − 5.25% NaOCl: No biologic sealing in 16 roots. The surface of cementum was irregular in 15 roots. There was severe inflammatory infiltrate in 12 roots at one or more sites located both near the root apex and distant. The periodontal ligament space was very thick in 12 roots, moderately thickened in 6 roots, and only slightly thickened in 1 root. The alveolar bone showed extensive areas of active resorption and 14 roots had osteoclasts. Group II - Chlorhexidine: There was partial apical closure of the root apex in 7 roots and no closure in 11. Diffuse inflammation was mild in 3 specimens, moderate in 11, and severe in 4 roots. The periodontal ligament space was slightly thickened in six roots, moderately thickened in seven, and severely thickened in five roots. The apical alveolar bone had areas of active resorption without medullary spaces and with osteoclasts. | Group III − 5.25% NaOCl: There was closure of the root apex in seven roots, partial closure in eight, and no closure in three roots. The periodontal ligament space was moderately thickened in 7 roots, nearly normal in 10, and severely thickened in 1. There were often osteoblasts on the surface of the alveolar bone, and active resorption was seen in only one case. Group IV − 2% Chlorhexidine digluconate: There was complete closure of the apex in seven specimens with cemento-mineralized tissue. The apical cementum was regular with newly formed mineralized tissue in previously resorbed areas. The periodontal ligament space was normal or moderately thick in 14 roots and severely thick in 4 roots. There was a severe inflammatory infiltrate in only one specimen. Normal alveolar bone contained osteocytes in its interior and osteoblasts on its surface. |
Leonardo et al. [27] 1995 (Brazil) | There was persistence of the lesion in 13 of the 15 specimens analyzed, with virtually no formation of repair cementum in any specimen. The periodontal space width was marked, with group 2 having the greatest periodontal width. The inflammatory reaction was also more severe, with more extensive areas of bone resorption. | The apical root surface was frequently covered with repair cementum. The periodontal space was normal in 3 cases, slightly thickened in 7, and severely thickened in 6. Less intense inflammation was seen near the apical region at the level of the ramifications. Newly formed trabecular bone was frequently present in alveolar bone, surrounded with numerous osteoblasts and occasional osteoclasts. The alveolar process presented wide medullar spaces and a discrete amount of neoformed trabecular bone. |
Katebzadeh et al. [28] 1999 (USA) | Overall results: Number of observations: 120, Mean: 1.73, SD: 0.80, Minimum: 1.0, Maximum: 3.0 / Frequency of inflammation scores: 0 = 0%, 1 = 48%, 2 = 30%, 3 = 22% | Overall results: Nº of observations: 105, Mean: 1.38, SD: 0.80, Minimum: 0, Maximum: 3.0 /Frequency of inflammation scores: 0 = 17%, 1 = 32%, 2 = 48%, 3 = 3% |
Hidalgo et al. [29] 2016 (Brazil) | 120 days: Periodontal ligament: 0% with normal ligament, 20% mildly increased, 70% moderately increased and 10% with severely increased ligament. Inflammatory infiltrate: 40% absent, 40% mild, 15% moderate, and 5% severe. Bone and cement resorption: 10% of groups with resorption. Presence of biological sealing: 95% absent sealing, 5% partial sealing, and 0% total sealing. 180 days: Periodontal ligament: 5% of specimens with normal ligament, 35% with mildly enlarged ligament, 55% moderately increased ligament, and 5% with severely increased ligament. Inflammatory infiltrate: 34% absent, 61% mild, and 5% moderate. Bone and cement resorption: 66% with no resorption and 34% with resorption. Presence of biological sealing: 89% no sealing, 11% partial sealing, and 0% total apical biological sealing. | 120 days: Periodontal ligament: The ligament was normal in 10% of the specimens, mildly enlarged in 60%, moderately enlarged in 30%, and 0% severely enlarged. Inflammatory infiltrate: 50% of specimens with no infiltrate and 50% with mild. Bone and cement resorption: 100% of the cases did not show resorption. Presence of biological sealing: 50% no sealing, 17% partial sealing, and 33% total sealing. 180 days: Periodontal ligament: normal in 35% of specimens, mildly increased in 20%, moderately increased in 20%, and severely increased in 25%. Inflammatory infiltrate: 40% no infiltrate, 55% mild, and 5% moderate. Bone and cement resorption: 85% with no resorption and 15% with resorption. Presence of biological sealing: 52% no sealing, 29% with partial sealing, and 19% with total sealing. |
Cintra, [30] 2008 (Brazil) | Group I – Saline solution: 100% of failure, determined by moderate to severe acute inflammatory infiltrate and/or chronic inflammatory infiltrate associated with the presence of microorganisms in all specimens. Group II – Natrosol: 1 specimen without microscopic evidence of bacteria, but isolated focus of acute inflammation was present. 100% of failure was considered in the group. Group III – 2.5% Sodium hypochlorite: 44% of endodontic treatment success, determined by the presence of chronic inflammatory infiltrate associated with extrusion of filling material. Group IV – 2% chlorhexidine gel: 44% success rate determined by the absence of acute inflammatory infiltrate and chronic inflammation associated with microorganisms. Group V – 2% chlorhexidine fluid: 27.3% of success determined by the absence of acute inflammatory infiltrate and chronic inflammation associated with the presence of microorganisms. | Group VI – Saline solution: 37.5% of success determined by the absence of acute inflammatory infiltrate and chronic inflammation associated with the presence of microorganisms. Group VII – Natrosol: 30% of success determined by the absence of acute inflammatory infiltrate and chronic inflammation associated with the presence of microorganisms. Group VIII – Sodium hypochlorite 2.5%: 54.6% of success. GROUP IX – 2% Chlorhexidine gel: 60% of success rate determined by the absence of acute inflammatory infiltrate and chronic inflammation associated with the presence of microorganisms. Group X – 2% Chlorhexidine fluid: 50% of success rate, determined by the absence of acute inflammatory infiltrate and microorganisms. |
Liévana, [31] 2018 (Brazil) | Inflammatory infiltrate - Absent: 0 (0%), Mild: 2 (16.66%), Moderate: 3 (25%), Severe: 7 (58.33%). Periodontal ligament thickness - Normal: 0 (0%), Slightly Increased: 1 (8.33%), Moderately Increased: 5 (41.66%), Severely Increased: 6 (50%). Reabsorption of mineralized tissues - Absent: 2 (16%), Present: 10 (83.33%) | Group III- Calen: Inflammatory infiltrate - Absent: 8 (72.72%), Mild: 2 (18.18%), Moderate: 1 (9.09%), Severe: 0 (0%). Periodontal ligament thickness - Normal: 1 (9.09%), Slightly Increased: 5 (45.45%), Moderately Increased: 5 (45.45%), Severely Increased: 0 (0%). Reabsorption of mineralized tissues - Absent: 6 (54.54%), Present: 5 (45.45%) |
Huamán, [32] 2018 (Brazil) | Group III: Persistence of periapical lesions and absence of repair. Inflammatory infiltrate - Absent: 0 (0%), Mild: 2 (16.7%), Moderate: 4 (33.3%), Severe: 6 (50%). Thickness of the periodontal ligament - Normal: 0 (0%), Slightly Increased: 0 (0%), Moderately Increased: 2 (16.6%), Severely Increased: 10 (83.4%); Cement resorption - Absent: 0 (0%), Present: 12 (100%); Biological Apical Sealing - Complete: 0 (0%), Partial: 0 (0%), Missing: 12 (100%); Bone resorption - Absent: 1 (8.3%), Present: 11 (91.7%); Mean thickness of periodontal ligament (mm): 1.26 (SD 0.45) | Group II: Inflammatory infiltrate - Absent: 0 (0%), Mild: 11 (84.6%), Moderate: 2 (15.4%), Severe: 0 (0%); Thickness of the periodontal ligament - Normal: 0 (0%), Slightly Increased: 3 (23.1%), Moderately Increased: 8 (61.53%), Severely Increased: 2 (15.4%); Cement resorption - Absent: 13 (100%), Present: 0 (0%); Apical Sealing - Complete: 4 (30.8%), Partial: 7 (53.84%), Absent: 2 (15.4%); Bone resorption - Absent: 13 (100%), Present: 0 (0%); Mean thickness of the periodontal ligament (mm): 0.31 (SD = 0.19) |
Otoboni Filho [33], 2000 (Brazil) | Group I (Sealapex) - Medium: Newly formed cementum - Thickness: 1.31; Extension: 1.12; Biological sealing accessory foramina: 1.81; Biological sealing of the main foramina: 1.62; Reabsorption: 1.37; Bone tissue resorption: 1.62; Presence of bacteria: 3.43; Acute inflammation: Internal 1,12; External: 1.06; Chronic inflammation: Internal: 2.87; External: 2.68; Periodontal Ligament: Thickness: 2.37; Organization: 2.12; Giant Cells: 1.43 – General average: 1.81. Group II (Sealer 26) - Average: Neoformed cement: Thickness: 1.62; Extension: 1.63; Biological sealing accessory foramina: 2.56; Biological sealing of the main foramina: 2.56; Reabsorption: 2.18; Bone tissue resorption: 1.93; Presence of bacteria: 3.62; Acute inflammation: Internal 1.87; External: 1.68; Chronic inflammation: Internal: 2.62; External: 2.62; Periodontal Ligament: Thickness: 2.75; Organization: 2.50; Giant Cells: 1.50 – Overall Average: 2.16 | Group III (07 days- Sealapex) - Average: Neoformed cement: Thickness: 1.06; Extension: 1.12; Biological sealing accessory foramina: 1.56; Biological sealing of the main foramina: 1.00; Reabsorption: 1.12; Bone tissue resorption: 1.43; Presence of bacteria: 2.87; Acute inflammation: Internal 1.00; External: 1.00; Chronic inflammation: Internal: 1.81; External: 1.75; Periodontal Ligament: Thickness: 2.18; Organization: 1.93; Giant Cells: 1.25 – General average: 1.5. Group IV (07 days – Sealer 26) - Average: Neoformed cement: Thickness: 1.50; Extension: 1.12; Biological sealing accessory foramina: 2.18; Biological sealing of the main foramina: 2.18; Reabsorption: 1.18; Bone tissue resorption: 1.56; Presence of bacteria: 2.50; Acute inflammation: Internal 1.06; External: 1.06; Chronic inflammation: Internal: 2.37; External: 2.56; Periodontal Ligament: Thickness: 2.62; Organization: 2.31; Giant Cells: 1.31 – General average: 1.80 Group V: (14 days – Sealapex) - Average: Neoformed cement: Thickness: 1.18; Extension: 1.12; Biological sealing accessory foramina: 1.56; Biological sealing of the main foramina: 1.12; Reabsorption: 1.12; Bone tissue resorption: 1.50; Presence of bacteria: 1.75; Acute inflammation: Internal 1.00; External: 1.00; Chronic inflammation: Internal: 1.75; External: 1.56; Periodontal Ligament: Thickness: 2.50; Organization: 1.93; Giant Cells: 1.06 – General average: 1.43. Group VI: (14 days – Sealer 26) - Average: Neoformed cement: Thickness: 1.18; Extension: 1.31; Biological sealing accessory foramina: 2.12; Biological sealing of the main foramina: 2.00; Reabsorption: 1.25; Bone tissue resorption: 1.31; Presence of bacteria: 1.93; Acute inflammation: Internal 1.00; External: 1.00; Chronic inflammation: Internal: 2.18; External: 1.93; Periodontal Ligament: Thickness: 2.75; Organization: 1.93; Giant Cells: 1.25 – Overall Average: 1.64 |
Silva [34], 2004 (Brazil) | Group I: The apical and periapical tissues presented severe inflammatory reaction in most of the analyzed cases. In all 20 cases there was apical inflammatory infiltrate in an extension greater than half of the apical periodontal space. Apical periodontal space was greater than 1.06 mm, corresponding to score 4. Large active areas of bone resorption were found in this group. Group III: Inflammatory cells were observed near the apical foramen with diffuse distribution throughout the periapical periodontal space. The level of periapical inflammatory infiltrate had score 4 in almost all cases in this group (n = 18) (located above half of the apical periodontal space). Apical root resorption was present in all cases in this group. | Group II: The apical and periapical inflammatory reaction was less intense than that for group I. As for the extent of the apical inflammatory infiltrate, the vast majority of cases (n = 11) were arranged with a score of 2 (restricted to the apical foramen). Apical root resorption was not observed in the vast majority of specimens, and in most cases, there was also bone repair. Group IV: The inflammatory reaction in the apical and periapical region was mild. The existing inflammatory cells were concentrated in the region of the apical foramen in most cases. Apical root resorption was present up to half of the cementum thickness in 7 cases and absent in the remaining cases. |
César [35], 2003 (Brazil) | Group I: Biological Apical Sealing (Average: 1.05) – Absent: 19, Partial: 1, Complete: 0; Inflammatory Infiltrate (Average: 3.75) – Absent: 0, Mild: 0, Moderate: 5, Severe: 15; Thickness of the periodontal ligament (Average: 3.80) – Normal: 0, Mild: 0, Moderate: 4, Severe or Extensive: 16; Cement Resorption (Average: 2.00) – Absent: 0, Present: 20; Dentin Resorption (Average: 1.00) – Absent: 20, Present: 0; Bone Resorption (Average: 2.00) - Absent: 0, Present: 0 | Group II (Calen PMCC): Biological Apical Sealing (Average: 2.10) – Absent: 4, Partial: 10, Complete: 16; Inflammatory Infiltrate (Average: 2.55) – Absent: 0, Mild: 12, Moderate: 5, Severe: 3; Thickness of the periodontal ligament (Average: 2.60) – Normal: 0, Mild: 10, Moderate: 8, Severe or Extensive: 2; Cement Resorption (Average: 1.10) – Absent: 18, Present: 2; Dentin Resorption (Average: 1.00) – Absent: 20, Present: 0; Bone Resorption (Average: 1.10) – Absent: 18, Present: 2. Group III (Calapset): Biological Apical Sealing (Average: 1.80) – Absent: 6, Partial: 12, Complete: 2; Inflammatory Infiltrate (Average: 3.25) – Absent: 0, Mild: 3, Moderate: 9, Severe: 8; Thickness of the periodontal ligament (Average: 3.35) – Normal: 0, Mild: 0, Moderate: 13, Severe or Extensive: 7; Cement Resorption (Average: 1.40) – Absent: 12, Present: 8; Dentin Resorption (Average: 1.00) – Absent: 20, Present: 0; Bone Resorption (Average: 1.30) - Absent: 14, Present: 6 |
Lopes [36], 2018 (Brazil) | Group I (120 days): There were some areas of unrepaired resorption in the apical cementum. The periodontal ligament was moderately enlarged, with few collagen fibers. The inflammatory infiltrate was moderate and predominantly mononuclear. Few collagen fibers were observed, and the alveolar bone was often bare. Average lesion area: 3.29 (± 1.07); Group III (180 days): same pattern, no significant differences; Average lesion area: 120 = 3.29 (± 1.07); 180 = 3.25 (± 2.97) | Group II (120 days): Showed areas of repaired resorption in most specimens. The periodontal ligament was slightly enlarged, with advanced repair and the presence of collagen fibers. There was a scarce and diffuse presence of inflammatory cells. Average lesion area: 120 = 1.18 (± 0.41). Group IV (180 days): same pattern, without significant differences. Periapical lesions were smaller compared to lesions in the groups treated with aPDT and single session. Average lesion area: 180 = 1.41 (± 0.47) |