Efficacy of soft tissue augmentation procedures on tissue thickening around dental implants: A systematic review and meta-analysis.

OBJECTIVES: The first focused question (FQ1) was: What is the efficacy of connective tissue graft (CTG), as compared to the absence of soft tissue grafting procedure, in terms of gain in peri-implant soft tissue thickness (STT) reported by randomized controlled clinical trials (RCTs) or controlled clinical trials (CCTs)? The second focused question (FQ2) was: What is the efficacy of CTG, as compared to soft tissue substitutes, in terms of gain in peri-implant STT reported by RCTs or CCTs? MATERIALS AND METHODS: A manual and electronic search was performed for each question to identify RCTs and CCTs published up to July 2020. The primary outcome variable was changes in peri-implant STT and secondary outcomes were marginal bone level (MBL), clinical parameters for the diagnosis of peri-implant health, changes in the position of peri-implant soft tissues, esthetic outcomes, and patient-related outcome measures (PROMs). For primary and secondary outcomes, data reporting mean values and standard deviations for each study were extracted. Weighted mean differences (WMDs) or standardized mean differences as well as 95% confidence intervals (CIs) and prediction intervals (PIs) were calculated. RESULTS: Eight trials were included to answer the first focused question and eight to answer the second one, providing data for 254 and 192 patients, respectively. For the first focused question, a statistically significant difference of 0.64 mm in STT was found in favor of the grafted group (n = 8; 95% CI [0.16; 1.13]; 95% PI [-1.06; 2.35]; p = .01). Moreover, sites treated with CTG exhibited statistically significant less recession than implants without a graft (n = 4; WMD = 0.50 mm; 95% CI [0.19; 0.80]; 95% PI [-0.70; 1.69]; p < .001). For the second focused question, the meta-analysis showed a statistically significant gain of STT in the CTG group when compared to soft tissue substitutes (n = 8; WMD = 0.51 mm; 95% CI [0.28; 0.75]; 95% PI [-0.09; 1.12]; p < .001). Furthermore, the use of CTG resulted in significantly higher pink esthetic score values (n = 3; WMD = 1.02; 95% CI [0.29; 1.74]; 95% PI [-3.67; 5.70]; p = .01) and less recession (n = 2; WMD = 0.50 mm; 95% CI [0.10; 0.89]; 95% PI [not estimable]; p = .014) when compared to soft tissue substitutes. No statistically significant differences between groups were observed for any of the following secondary variables: MBL, clinical parameters for the diagnosis of peri-implant health, position of the interproximal tissues, keratinized mucosa or PROMS (p > 0.05), except for medication intake, which was significantly higher when using CTG as compared to soft tissue substitutes (n = 2; WMD = 1.68; 95% CI [1.30; 2.07]; 95% PI [not estimable]; p < .001). CONCLUSIONS: Soft tissue augmentation procedures are efficacious on soft tissue thickening and, in particular, CTG demonstrated a significant STT gain when compared to no graft or soft tissue substitutes.

Intra- and inter-examiner reliability in classifying periodontitis according to the 2018 classification of periodontal diseases.

AIM: To evaluate the inter-examiner reliability in classifying periodontitis using the 2018 classification of periodontal diseases, when used by postgraduate students, academics, and specialist clinicians trained in European Federation of Periodontology (EFP) and American Academy of Periodontology (AAP) postgraduate-accredited programmes. MATERIALS AND METHODS: An online survey including five patients with periodontitis was sent twice to seven specialists in periodontology to provide the staging and grading characteristics. After agreeing on a "gold-standard" classification, the same questionnaire was sent to 16 EFP and 73 AAP postgraduate programmes, to be answered by their faculty, graduates, and students. The responses were compared with the gold-standard classification, and the inter-examiner agreement was calculated. RESULTS: One-hundred and seventy-four participants completed the survey. The inter-examiner agreement resulted in 68.7% in assigning the stage, 82.4% in assigning the grade, and 75.5% in assigning the extent. The academic position and the experience of the participants did not have any significant influence on classifying periodontitis as the gold standard. CONCLUSIONS: The use of the 2018 periodontitis classification resulted in high inter-examiner reliability when used by a specialist group of clinicians, postgraduate students, and academicians, irrespective of their current position and experience. Given the low response rate and potential selection bias, results pertaining to the use of this system in classifying periodontitis should be interpreted with caution.

Ridge preservation in molar sites comparing xenograft versus mineralized freeze-dried bone allograft: A randomized clinical trial.

OBJECTIVES: The main objective of the study was to compare the dimensional ridge changes and the histological composition after the use of an allograft or xenograft and a resorbable membrane in ridge preservation in molar sites and to evaluate the influence of bone plate thickness on dimensional changes and the need of lateral sinus augmentation following ridge preservation. MATERIALS AND METHODS: Twenty-four patients in need of maxillary or mandibular first or second molar extraction and subsequent implant placement were included and randomly assigned to a group; allograft or xenograft, plus a collagen membrane. Cone-beam computed tomographies were obtained after molar extraction and after 5 months. A bone sample was harvested at the time of implant placement and analyzed by histomorphometry. RESULTS: Bone ridge was reduced significantly. Major changes in width occurred at 1 mm from the bone crest (-2.93 ± 2.28 mm) (p = .0002), while in height, the greatest reduction occurred at the buccal area (-1.97 ± 2.21 mm) (p = .0006). However, differences between groups were not significant. Thicker buccal bone plates exhibited less bone remodeling, while histologically, both biomaterials resulted in similar tissue composition. The resulting available bone height in the implant site measured 7.30 ± 3.53 mm initially and 6.8 ± 3.61 mm after 5 months which allowed implant placement without the need for lateral sinus augmentation in all cases. Still, 55% of the preserved areas needed transcrestal sinus lift. CONCLUSION: Ridge preservation in molar sites using a mineralized allograft or xenograft provides similar dimensional and histomorphometrical results after 5 months.

Fracture Resistance in Non-Vital Teeth: Absence of Interproximal Ferrule and Influence of Preparation Depth in CAD/CAM Endocrown Overlays-An In Vitro Study.

There is ample evidence to support the use of endocrowns to restore endodontic teeth. However, the influence of the position of the interproximal margins on fracture strength has not yet been studied. The aim was to determine the relationship between the apicocoronal position of the interproximal restorative margins and fracture resistance in nonvital teeth restored with CAD/CAM endocrown overlays. Forty extracted human maxillary premolars were prepared for endocrown overlay restorations without ferrule on the interproximal aspects and classified according to the position of the interproximal restoration margins in relation to the alveolar crest: 2 mm (group A), 1 mm (group B), 0.5 mm (group C), and 0 mm (group D). Fracture strength was measured using a universal testing machine applying a compressive force to the longitudinal tooth axis. Group A had a mean fracture resistance of 859.61 (±267.951) N, group B 1053.9 (±333.985) N, group C 1124.6 (±291.172) N, and group D 780.67 (±183.269) N, with statistical differences between groups. Group C had the highest values for fracture strength compared to the other groups (p < 0.05). The location of the interproximal margins appears to influence the fracture resistance of CAD/CAM endocrown overlays. A distance of 0.5 mm between the interproximal margin and the alveolar crest was associated with increased fracture resistance.

Keratinized tissue gain after free gingival graft augmentation procedures around teeth and dental implants: A prospective observational study.

AIM: The primary goal was to compare the amount of keratinized tissue width (KTW) gain after free gingival graft (FGG) procedures around implants and teeth after 6 and 12 months of healing. MATERIALS AND METHODS: Patients with mucogingival defects (<2 mm of KT) around teeth and implants underwent a gingival augmentation procedure by means of a FGG. Clinical measurements were performed with an individual stent to determine keratinized tissue width (KTW), length (KTL), graft shrinkage (GS) and gingival margin position (GMP) at 2 weeks, 6 weeks, 3 months, 6 months and 12 months after surgery. RESULTS: Twenty-nine patients (35 sites) participated in this prospective study. After surgery, KTW decreased and GS increased significantly in both treatment groups during the whole follow-up period, but the biggest changes were observed at 6 weeks. When comparing both treatment groups, implant sites showed significantly more reduction in KTW and more GS. Thus, at 12 months, KTW and GS reduced 2.03 ± 2.1 mm and 36.74 ± 38.2% in the teeth group and 2.91 ± 12.03 mm and 61.8 ± 36.25% around implants, respectively. CONCLUSIONS: A significantly greater reduction in KTW and more GS might be expected at implant sites.

Evaluation of the effect of probiotics in the treatment of peri-implant mucositis: a triple-blind randomized clinical trial.

OBJECTIVES: To determine if the treatment of mucositis with mechanical debridement, 0.12% chlorhexidine, and a further application of Lactobacillus reuteri (L. reuteri) will result in an improvement of the clinical and microbiological parameters in comparison to the treatment with mechanical debridement and 0.12% chlorhexidine alone. MATERIAL AND METHODS: Fifty dental implants with mucositis in 50 patients were randomly assigned to one of the following groups: mechanical debridement, 0.12% chlorhexidine mouthwash, and the subsequent administration of a probiotic agent (test group) or mechanical debridement and 0.12% chlorhexidine mouthwash (control group). Data were analyzed to determine clinical and microbiological changes during treatment and after a follow-up period of 3 months. RESULTS: After the administration of 0.12% chlorhexidine, all clinical parameters improved in the test and the control group, observing a significant decrease in Full Mouth Plaque Index (FMPI), full mouth bleeding on probing (FMBOP), Plaque Index (PI), and bleeding on probing (BOP) at the implant. However, following the administration of probiotics or placebo, the clinical variables, except for probing pocket depth, slightly and progressively increased up to 3 months of follow-up, but without reaching baseline levels. From a microbiological point of view, no major alterations of the subgingival microflora were recorded at different time points between groups during the study. CONCLUSIONS: Treatment with mechanical debridement, oral hygiene reinforcement, and administration of 0.12% chlorhexidine was effective in reducing mucositis, but it did not always result in complete resolution of inflammation. The administration of probiotics did not seem to provide an additional clinical or microbiological benefit. CLINICAL RELEVANCE: The use of probiotics does not seem to provide an additional benefit in the treatment of peri-implant mucositis.

Comparison of Periodontal Biotypes Between Maxillary and Mandibular Anterior Teeth: A Clinical and Radiographic Study.

Periodontal biotype is a key element influencing esthetic treatment outcomes in clinical practice. However, while the soft and hard tissue thicknesses of maxillary anterior teeth have been widely studied, information regarding mandibular anterior teeth is scarce. Therefore, the aim of this study was to determine whether there is a relationship in terms of hard and soft tissue thickness between maxillary and mandibular anterior teeth. The present study included 90 maxillary and 90 mandibular anterior teeth in 15 healthy patients. Clinical and cone beam computed tomography measurements were taken to determine gingival and buccal bone thickness, respectively, and a correlation was made between maxillary and mandibular anterior teeth. No statistically significant differences were found when comparing gingival and buccal bone thickness at the crestal third and midpoint of maxillary and mandibular teeth (P > .05). However, some differences were observed at the apical third between the two groups. The results suggest that soft and hard tissue dimensions of maxillary and mandibular anterior teeth are comparable, especially in the coronal third. However, more studies are necessary to confirm that maxillary anterior teeth can be used as a reference when dealing with mandibular incisors and canines.

Bone volume changes after immediate implant placement with or without flap elevation.

OBJECTIVES: The aims of this prospective study were to evaluate bone dimensions after immediate implant placement with simultaneous grafting of the buccal gap, to determine if initial buccal bone width had an influence on bone remodelling and to compare bone volume changes using a flap or a flapless approach after 6 months of healing. MATERIAL AND METHODS: This prospective study included patients who required an extraction and a subsequent immediate implant placement at a non-molar site. In those cases where tooth extraction was not feasible with a flapless approach (test group) a mucoperiosteal flap was carefully elevated (control group). After extraction, a cone beam computed tomography (CBCT) was taken. Then, an implant was placed and the buccal gap was grafted using anorganic bovine bone. After 6 months of healing, a second CBCT was performed. A blinded investigator superimposed both images and performed a series of measurements to determine bone volume changes between the two time points. RESULTS: Thirty-five patients were included in this study, 20 of which belonged to the test group. All together, the differences between baseline and 6 months in buccal plate height, lingual plate height and in ridge width at 2, 4 and 6 mm were 0.48 ± 1.35; 0.58 ± 1.51; 0.64 ± 0.81; 0.59 ± 1.36 and 0.52 ± 1.16, respectively. Only a moderate correlation was observed between initial buccal plate width and buccal plate height at 6 months (P = 0.0001). No statistically significant differences were observed between flap and flapless approach. CONCLUSIONS: A mean reduction of around 0.5 mm in height and width after placing immediate implants and filling the residual gap with anorganic bovine bone may be expected. No significant association between initial buccal bone width and ridge width at 6 months was seen. No statistically significant differences were found between the two treatment protocols although more ridge reduction was observed for the flap group.

Radiographic and histological evaluation of deproteinized bovine bone mineral vs. deproteinized bovine bone mineral with 10% collagen in ridge preservation. A randomized controlled clinical trial.

OBJECTIVES: The aims of this randomized clinical trial were to compare the dimensional changes and the histological composition after using deproteinized bovine bone mineral (DBBM) or deproteinized bovine bone mineral with 10% collagen (DBBM-C) and a collagen membrane in ridge preservation procedures. MATERIAL AND METHODS: Patients who required an extraction and a subsequent implant-supported rehabilitation at a non-molar site were recruited. After extraction, a cone beam computed tomography (CBCT) was performed and sites were randomly treated either with DBBM or DBBM-C plus a collagen membrane. At 5 months, before implant placement, a second CBCT was performed and a biopsy of the area was obtained. A blinded investigator superimposed the CBCTs and performed measurements to determine bone volume changes between the two time points. Additionally, a histomorphometric analysis of the biopsies was performed in a blinded manner. RESULTS: Eleven sites belonged to the DBBM group and eleven to the DBBM-C group. All together, a significant reduction in height and width was observed at 5 months of healing, but no statistically significant differences were observed between the DBBM and the DBBM-C group. The histomorphometric analysis revealed a similar composition in terms of newly formed bone, connective tissue and residual graft particles in both groups. CONCLUSIONS: Deproteinized bovine bone mineral with 10% collagen showed a similar behaviour as DBBM not only in its capacity to minimize ridge contraction but also from a histological point of view. Thus, both graft materials seem to be suitable for ridge preservation procedures.

Histomorphometric results in ridge preservation procedures comparing various graft materials in extraction sockets with nongrafted sockets in humans: a systematic review.

INTRODUCTION: The aim of this systematic review was to evaluate, from a histological point of view, the amount of newly formed bone in ridge preservation procedures using various graft materials in comparison with natural healing (NH) and to determine which is the ideal type of graft to be used. MATERIALS AND METHODS: A search strategy was developed to find articles in a human model published between 1990 and January 2013 in English language using MEDLINE database. RESULTS: Thirty-four articles were included in this systematic review. When comparing the percentage of newly formed bone using various grafting materials with NH, calcium sulfate, magnesium enriched hydroxyapatite, and porcine-derived bone grafts offered the best outcomes. However, due to the heterogeneity of the included studies, the search was extended to determine which type of graft resulted in greatest bone formation. CONCLUSION: When comparing ridge preservation with NH, only 3 studies encountered a greater amount of newly formed bone in the ridge preservation group, whereas the rest did not find statistically significant differences or even observed a greater percentage of newly formed bone in the control group. Therefore, more studies are needed to determine whether the use of graft materials enhances new bone formation in contrast to NH alone and to determine the most effective bone grafting material.