Assessment of the effect of the corticotomy-assisted orthodontic treatment on the maxillary periodontal tissue in patients with malocclusions with transverse maxillary deficiency: a case series.

BACKGROUND: The aim of the study was to assess the effect of corticotomy-assisted orthodontic treatment on soft tissue clinical parameters in patients with malocclusions with transverse maxillary deficiency. METHODS: The study included 20 generally healthy adult individuals with malocclusion, who underwent a corticotomy-assisted orthodontic treatment in maxilla. During the corticotomy performed after full-thickness flap elevation, only the buccal cortical plate was cut with the use of OTS-7, OTS7-4, OTS7-3 ultrasound tips of the piezosurgery device (Mectron s. p. a., Italy). A clinical examination was performed prior to the corticotomy procedure, then repeated - 3, 6, 9 and 12 months after the procedure. The following parameters were assessed: FMPI (full mouth plaque index), FMBOP (full mouth bleading on probing), PD (probing depth), CAL (clinical attachment level), GR (gingival recession height), RW (recession width), PH (papilla height), PW (papilla width), BS (bone sounding), biotype and KT. RESULTS: There was a statistically significant reduction in PD (mean difference: 0.06; 95% Cl: - 0.33, - 0.18), CAL (mean difference: 0.07; 95% Cl: - 0.33, - 0.19), PH (mean difference: 0.26; 95% Cl: - 0.47, 0.05) and BS (mean difference: 0.13; 95% Cl: - 0.41, - 0.14) after the treatment. Statistically significant changes were also noted in relation to KT (mean difference: 0.17; 95% Cl: - 0.07, 0.27) and biotype (mean difference: 0.07; 95% Cl: 0.26, 0.39), which thickness increased significantly after the treatment. No statistically significant differences were observed in GR, RW and PW. CONCLUSIONS: The corticotomy-assisted orthodontic treatment did not jeopardize the periodontal clinical status in maxilla. There is a need for further studies on a larger number of patient to compare the clinical findings with a control group as well as in patients with conventional orthodontic treatment in a longer follow-up time to find out more about the post-treatment periodontal tissue changes and stability.

Evaluation of concordance between CAD/CAM and clinical positions of abutment shoulder against mucosal margin: an observational study.

BACKGROUND: While working on CAD/CAM-customized abutments, the use of standard impression copings with a circular diameter produces inconsistency within the emergence profile. It may begin with a collapse of the supra-implant mucosa during impression taking, then lead to a computer-generated mismatch of the position and outline of the abutment shoulder, and consequently result in a compromised outcome of anticipated treatment. The aim of the study was to compare the virtual and clinical positions of the abutment shoulder in relation to the mucosal margin after the abutment delivery. METHODS: Conventional open-tray impression takings followed uncovering surgery. Master casts were scanned with a desktop scanner. Clinical examinations took place after abutment's insertion and temporization (T1) and prior to cementation of the definitive crown (T2). The distances between the abutment shoulder and marginal soft tissue were measured intraorally in four aspects and juxtaposed with those on the virtual model. RESULTS: The study evaluated 257 dental implants and CAD/CAM-customized abutments. As T1 and T2 showed, there was a positive correlation between the virtually designed abutment shoulder position and matching clinical location relative to the mucosal margin. In 42.1% of cases, the distance between the mucosal margin and the abutment shoulder did not change. It increased in 36.3% of cases while a decrease occurred in 21.6% of them. CONCLUSIONS: Computer-set position of the abutment shoulder in relation to the mucosal margin can be predictably implemented in clinical practice.

Effect of nonsurgical periodontal treatment in conjunction with either systemic administration of amoxicillin and metronidazole or additional photodynamic therapy on the concentration of matrix metalloproteinases 8 and 9 in gingival crevicular fluid in patients with aggressive periodontitis.

BACKGROUND: To evaluate in patients with aggressive periodontitis (AgP) the effect of nonsurgical periodontal treatment in conjunction with either additional administration of systemic antibiotics (AB) or application of photodynamic therapy (PDT) on the gingival crevicular fluid (GCF) concentration of matrix metalloproteinases 8 and 9 (MMP-8 and -9). METHODS: Thirty-six patients with AgP were included in the study. Patients were randomly assigned to treatment with either scaling and root planing (SRP) followed by systemic administration of AB (e.g. Amoxicillin + Metronidazole) or SRP + PDT. The analysis of MMP-8 and -9 GCF concentrations was performed at baseline and at 3 and 6 months after treatment. Nonparametric U-Mann-Whitney test was used for comparison between groups. Changes from baseline to 3 and 6 months were analyzed with the Friedman's ANOVA test with Kendall's index of consistency. RESULTS: In the AB group, patients showed a statistically significant (p = 0.01) decrease of MMP-8 GCF level at both 3 and 6 months post treatment. In the PDT group, the change of MMP-8 GCF level was not statistically significant. Both groups showed at 3 and 6 months a decrease in MMP-9 levels. However, this change did not reach statistical significance. CONCLUSIONS: Within the limits of the present study, it may be suggested that in patients with AgP, nonsurgical periodontal therapy in conjunction with adjunctive systemic administration of amoxicilin and metronidazole is more effective in reducing GCF MMP-8 levels compared to the adjunctive use of PDT.

Retention force assessment in conical crowns in different material combinations.

The puprose of this study was to evaluate retention force of conical double crowns in two material connections: gold casting alloy/gold casting alloy and gold casting alloy/gold electroforming alloy. 12 crown pairs of both material connections with the cone angles of 2°, 4° and 6° were made. Experiment of 10.000 in-and-out cycles was performed using a new device which allows the retentive force to be measured in continuous way without necessity of moving the samples to another device. It has been found that the higher the retentive force values, the lower the cone angle. Dispersion of the retention value was similar in both groups, but when cone angle was 2° or 4°, stability of retention force with the passage of time was higher in combinations with electroformed copings. The optimum solution was the cast alloy/cast alloy connection but only with cone angle 6°. However, retentive values seem to be too low to achieve proper retention of dentures.

Nonsurgical treatment of aggressive periodontitis with photodynamic therapy or systemic antibiotics. Three-month results of a randomized, prospective, controlled clinical study.

The aim of this randomized, controlled clinical study was to compare the short-term effects of nonsurgical periodontal therapy with the additional administration of systemic antibiotics (AB) and the same therapy with additional photodynamic therapy (PDT) in the treatment of patients with aggressive periodontitis (AP). Thirty-six patients with AP received full-mouth nonsurgical periodontal treatment (SRP) and were then randomly divided into two groups of 18 subjects each. Group AB received amoxicillin and metronidazole three times a day for 7 days. Group PDT received two applications of PDT on the day of SRP as well as at follow-up after 7 days. The following clinical parameters were measured at baseline and 3 months after therapy: plaque index (PLI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and clinical attachment level (CAL). After 3 months, PD was significantly reduced in both groups (from 5.0±0.8 mm to 3.2±0.4 mm with AB, and 5.1±0.5 mm to 4.0±0.8 mm with PDT; both p<0.001), while AB revealed significantly lower values compared to PDT (p = 0.001). In both groups, GR was not significantly changed. CAL was significantly reduced in both groups (PDT: 5.7±0.8 mm to 4.7±1.1 mm; p=0.011; AB: 5.5±1.1 mm to 3.9±1.0 mm; p<0.001) and differed significantly between the groups (p=0.025). The number of residual pockets (PD ≥4 mm) and positive BOP was reduced by AB from 961 to 377, and by PDT from 628 to 394. Pockets with PD ≥7 mm were reduced by AB from 141 to 7, and by PDT from 137 to 61. After 3 months, both treatments led to statistically significant clinical improvements. The systemic administration of antibiotics, however, resulted in significantly higher reduction of PD and a lower number of deep pockets compared to PDT.

Long-term follow-up of conical crown-retained dentures fabricated using different technologies.

This study presents the results of a long-term clinical evaluation of conical crown-retained dentures fabricated using different technologies. Four different material connections between the outer and inner crowns were used: cast gold/cast gold, cast gold/electroforming, nonprecious alloy/electroforming, and titanium abutment/electroforming. Technical failures and retention values were assessed. The best clinical outcome was found with dentures in which both crowns were cast from gold alloy. The most frequent technical failures were observed in restorations with electroformed outer crowns. Better clinical outcomes were noted when the electroformed outer crowns were used in dentures retained by implants as compared to dentures on natural dentition.