The efficacy of a porcine collagen matrix in keratinized tissue augmentation: a 5-year follow-up study.

BACKGROUND: When keratinized tissue width around dental implants is poorly represented, the clinician could resort to autogenous soft tissue grafting. Autogenous soft tissue grafting procedures are usually associated with a certain degree of morbidity. Collagen matrices could be used as an alternative to reduce morbidity and intra-operatory times. The aim of this study was to assess the efficacy of a xenogeneic collagen matrix as a substitute for soft tissue grafting around dental implants. METHODS: Fifteen consecutive patients underwent a vestibuloplasty and keratinized tissue reconstruction around dental implants, both in the mandible and the maxilla, with a porcine collagen matrix. The so obtained keratinized tissues were measured and evaluated after 6 months and 1, 4, and 5 years. RESULTS: The average gain of keratinized tissue was 5.7 mm. After 6 months, it was observed a resorption of 37%, after 1 year 48%, and after 5 years 59%. The mean gain of keratinized tissue after 5 years was 2.4 mm. Hemostatic effect and post-operative pain were evaluated too. All subjects referred minimal pain with no bleeding. No adverse reaction nor infection was noted. CONCLUSIONS: The present study showed the efficacy of a porcine collagen matrix in keratinized tissue augmentation. The possibility to use a soft tissue substitute is a great achievement as morbidity decreases and bigger areas can be treated in a single surgery.

Long-term survival rate of implants placed in conjunction with 246 sinus floor elevation procedures: results of a 15-year retrospective study.

OBJECTIVES: The aim of the present long-term study was to retrospectively evaluate the survival rate of implants placed in regenerated maxillary sinuses and to assess the influence of hypothetical predictors of implant failure. METHODS: A database including 218 patients who received dental implants after sinus lift procedures was analyzed. The following variables were systematically included and evaluated: type of graft material used, number of surgeries performed, and use of membranes to cover the lateral antrostomy and/or to repair accidental Schneiderian membrane perforations. The Kaplan-Meier estimator was used for comparisons among the groups. RESULTS: A total of 589 dental implants were positioned in 246 grafted sinuses and were in function for 3-186 months. The Kaplan-Meier cumulative survival rate was 98.3% after 15.5 years of follow-up. All implant losses occurred within 52 months (4.3 years) after augmentation. According to the log-rank test, no statistically significant difference was shown between each patient/implant variable (p>0.05). CONCLUSIONS: Despite the limitations inherent in this type of study, no statistically significant differences between the groups could be found. Intraoperative Schneiderian membrane perforations did not affect the outcome of the implants positioned. CLINICAL SIGNIFICANCE: The present long-term study is intended as a reference for clinicians approaching sinus floor elevation surgery in order to provide them with relevant operative findings. Since all the drawbacks occurred within the first 5 years, medium-term follow-up studies could be suitable for further retrospective evaluations.

Juvenile paradental cyst: presentation of a rare case involving second molar.

The aim of this article was to describe a rare case of paradental cyst of the permanent mandibular second molar. A 14-year-old girl was referred to Oral Surgery Department, Dental Clinic, IRCSS Fondazione Ca' Granda, University of Milan, Italy, for the evaluation of the deep probing located on the buccal aspect of her erupted mandibular left second molar. Clinical signs of inflammation were absent and the mucosa around the second molar appeared clinically normal. Pulp tests for the second molar were positive. The evaluation of the panoramic radiograph did not revealed radiolucency. The Cone-beam tomography showed a well-defined semilunar-shaped radiolucency demarcated by a fine radiopaque line. The cyst was enucleated. The histopathologic analisys revealed the presence of hyperplastic, non-keratinized squamous epithelium with heavy, dense inflammatory cell infiltrate in the epitelium and connective tissue wall. This analysis associated with macroscopic, clinical and radiografic examination confirmed the diagnosis of paradental cyst. A clinic-pathologic correlation, incorporating the surgical, radiographic and histologic findings, is required to obtain the final diagnosis of paradental cyst. Today, the treatment of choice is simple enucleation and thorough curettage of the cyst without extraction of the involved tooth, but if CT demonstrates erosions in the buccal or lingual cortices, marsupialization should be the treatment of choice.

Paradental cyst of the first molar: Report of a rare case with bilateral presentation and review of the literature.

The paradental cyst is a lesion classified and recognized by World Health Organization quite recently, which is related to an inflammatory process, especially pericoronitis, involving a tooth in eruption. The aim of this article is to report a rare bilateral case of paradental cyst. An 8-year-old boy presented to the Oral Surgery Department, Dental Clinic, Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Fondazione Ospedale Maggiore Policlinico, University of Milan, with the complaint of swelling over the buccal gingiva of his unerupted lower left first molar. Radiographs revealed a radiolucency involving the bifurcation and root area of teeth 36 and 46. The cysts were enucleated, maintaining the affected teeth in site; microscopic evaluation revealed a chronically inflamed cyst lined by a non-keratinized stratified squamous epithelium; the histopathology associated with macroscopic and radiographic examinations permitted the definitive diagnosis of a paradental cyst on the mandibular left and right first molars. The most recent literature shows the rarity of the paradental cyst occurring with bilateral localization. Because the paradental cyst can present variable clinical and radiographic signs, it is mandatory to correlate all clinical, radiographic, and histological data to obtain a definitive diagnosis.

Paradental cyst of the first molar: a report of two cases.

OBJECTIVE: The paradental cyst is an uncommon lesion associated with the permanent mandibular first or second molar in children just prior to tooth eruption. The purpose of this article is to present two cases of paradental cyst affecting the buccal aspect of permanent mandibular first molar of both young patients. We also discuss diagnosis, treatment and radiographic findings of the cases. PATIENTS AND METHODS: In both cases was made only the enucleation of cyst without extraction of the adjacent tooth. Lesional samples were sent for histopathologic analysis. RESULTS: The histopathologic analysis of both cases, revealed a lining of hyperplastic, nonkeratinized squamous epithelium with heavy, dense inflammatory cell infiltrate in the epithelium and connective tissue wall. The histopathology associated with macroscopic and radiographic examination permitted the definitive diagnosis of a paradental cyst on the mandibular left first molar. A follow-up of 1 year was carried out in both cases and no recurrences was noted; in the first case was observed the correct eruption of the mandibular permanent left first molar. CONCLUSIONS: A clinicopathologic correlation, incorporating the surgical, radiographic, and histological finding, is required to obtain the final diagnosis of paradental cyst. Today, the treatment of choice is simple enucleation and thorough curettage of the cyst without extraction of the involved tooth.

Could local anesthesia while breast-feeding be harmful to infants?

BACKGROUND: Few studies have been carried out on the levels and possible toxicity of local anesthetics in breast milk after parenteral administration. The purpose of this study is to determine the amount of lidocaine and its metabolite monoethyl-glycinexylidide (MEGX) in breast milk after local anesthesia during dental procedures. METHODS: The study population consisted of seven nursing mothers (age, 23-39 years) who received 3.6 to 7.2 mL 2% lidocaine without adrenaline. Blood and milk concentrations of lidocaine and its metabolite MEGX were assayed using high-performance liquid chromatography. The milk-to-plasma ratio and the possible daily doses in infants for both lidocaine and MEGX were calculated. RESULTS: The lidocaine concentration in maternal plasma 2 hours after injection was 347.6 +/- 221.8 microg/L, the lidocaine concentration in maternal milk ranged from 120.5 +/- 54.1 microg/L (3 hours after injection) to 58.3 +/- 22.8 microg/L (6 hours after injection), the MEGX concentration in maternal plasma 2 hours after injection was 58.9 +/- 30.3 microg/L, and the MEGX concentration in maternal milk ranged from 97.5 +/- 39.6 microg/L (3 hours after injection) to 52.7 +/- 23.8 microg/L (6 hours after injection). According to these data and considering an intake of 90 mL breast milk every 3 hours, the daily infant dosages of lidocaine and MEGX were 73.41 +/- 38.94 microg/L/day and 66.1 +/- 28.5 microg/L/day respectively. CONCLUSIONS: This study suggests that even if a nursing mother undergoes dental treatment with local anesthesia using lidocaine without adrenaline, she can safely continue breastfeeding.

Heritability of 39 orthodontic cephalometric parameters on MZ, DZ twins and MN-paired singletons.

The twin method is one of the most effective methods available for investigating genetically determined variables in orthodontics, as well as in other medical fields, depending on the variance in the shape and the size of skull and teeth, both on genetic and environmental influences. The former have been extensively evaluated and, in particular, most of the facial and dental cephalometric parameters have shown high heritability, the vertical parameters have a higher genetic control compared with the horizontal ones. Nevertheless, most of the results provided by twin research have been considered arbitrary if directly transferred to a singleton population and in further studies, including extensive analysis of the parents, familial and nutritional habits have been recommended. In this study, heritability of 39 lateral orthodontic cephalometric parameters has been estimated by both statistical method of path analysis and Dahlberg' quotient in three orthodontic samples of young monozygotic and dizygotic twins and same-sex pairs of singletons living together, matched for sex and age, to evaluate genetic versus environmental factors affecting heritability of craniofacial features in the aim to obtain results not only statistically significant but also transferrable to a singleton population. Different inheritance trends, showing the highest concordance of values between monozygotic twin pairs when compared with dizygotic twin pairs or the same-sex singletons paired group, come from the 39 selected lateral cephalometric parameters, confirming the hypothesis that strong genetic control is exerted especially on the vertical ones. Heritability seems to have more influence on anterior vertical parameters than posterior. Mandibular structure seems to be more genetically determined than mandibular size. All five Ricketts' cephalometric typological parameters confirm high heritability coefficients, the same applies to the linear horizontal McNamara's measurement and lower incisor to A-Pg line. The two tested statistical methods showed relevant concordance of results.

Copper-zinc superoxide dismutase in human and animal dental pulp.

The activity of the enzyme superoxide dismutase, scavenger of the superoxide anion (O2-.), was assayed in the normal dental pulp of man, dog, rabbit and pig. Very low levels of Cu-Zn-containing superoxide dismutase found in the pulpal tissue investigated support the hypothesis of a relationship between the reactivity of the dental pulp to inflammatory processes and a low protection against oxy-radicals.

[Gingival hyperplasia from calcium antagonists]. / Iperplasia gengivale da calcio-antagonisti.

The Authors have studied a sample of forty-four patients suffering from cardiovascular pathology treated with calcium-antagonist. They have evaluated the incidence and clinical-histological characteristics of gingival hyperplasia.