Radiographic evaluation of the distance between the restoration margin and the alveolar bone crest in dental implant patients: A retrospective study.

OBJECTIVES: The recently introduced Implant Disease Risk Assessment (IDRA) identifies a restoration margin-alveolar bone crest (RM-AC) distance of less than 1.5 mm as a key risk factor for peri­implant disease among eight major risk factors. This study evaluated the impact of the RM-AC distance on marginal bone loss (MBL) through radiographic analysis. METHODS: This retrospective cross-sectional study included 77 partially edentulous patients (39 females and 38 males, aged 22 to 76 years) with 202 platform-switched conical connection implants, cement-retained, implant-supported fixed restorations, and bone-level implants placed between 2016 and 2021. Dental implants were followed for least 6 to 36 months at follow up functional loading. Study participants were categorized into Group A (RM-AC distance ≤ 1.5 mm, n = 69) and Group B (RM-AC distance > 1.5 mm, n = 133). Twelve patients in Group B and five patients in Group A had no history of periodontal disease. The MBL was measured radiographically from the most coronal point of the implant shoulder to the alveolar bone, and the RM-AC distance was measured from the restoration margin to the alveolar crest. Multinomial logistic regression analysis was used for statistical evaluation. RESULTS: The incidence of MBL in Group A was statistically significant and 3.42 times higher than that in Group B. The rate of MBL in periodontitis Stage 4 was found to be 26.31 times higher than that in periodontitis Stage 2. The incidence of MBL was 6.097 and 5.02 times higher with increasing implant diameter and length, respectively. CONCLUSION: This study conclusively demonstrates that RM-AC distance ≤ 1.5 significantly increases the risk of MBL, particularly in patients with a history of periodontal disease. CLINICAL SIGNIFICANCE: This study highlights the critical role of maintaining an RM-AC distance greater than 1.5 mm in the prevention of MBL, particularly in patients with a history of periodontal disease. Since implant diameter and length have a significant impact on the risk of MBL, it emphasizes that implant demographics should also be carefully evaluated.

The effect of different gingival phenotypes on dimensional stability of free gingival graft: A comparative 6-month clinical study.

BACKGROUND: The aim of this study is to compare the effect of mesial and distal adjacent gingival phenotypes of the tooth or teeth region of free gingival graft (FGG) on the shrinkage ratio of graft at 6 months postoperatively. METHODS: Thirty-one patients with inadequate keratinized gingival width (KGW) around mandibular incisors were included in this study. The phenotype of the mesial and distal terminal teeth was evaluated by the probe transparency method and keratinized gingival thickness measurements; study groups were divided as thick and thin phenotype. The plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL) and recession height (GRH), recession width (GRW) and KGW measurements were recorded at baseline and sixth month. Vertical dimension of graft (VDG), horizontal dimension of graft (HDG), recipient area horizontal width (RAHW), recipient area vertical depth (RAVD) were recorded during surgery. The shrinkage ratio was calculated with a Java-based analysis program. RESULTS: There was no significant difference in the clinical and surgical measurements between the groups. KGW mean values for both of adjacent teeth increased at 6th month compared to baseline but there was no difference between the groups at 6 months. GRH value has decreased significantly in thick phenotype group at the 6th month. The shrinkage ratio was found 23.14 ± 12.21% and 17.76 ± 11.05% in the thin and thick phenotype group, respectively. The difference between the groups was not statistically significant (p = 0.210). CONCLUSION: The phenotype of the adjacent teeth has a similar impact on FGG shrinkage ratio at the sixth month. Thick phenotype of adjacent teeth seems to be more supportive for root coverage.