Journal of Dentistry, Shiraz University of Medical Sciences
Volume:23 Issue: 3, Sep 2022

Statement of the Problem: 

Bone morphogenetic protein (BMP), a potential osteoinductive agent, was systematically reviewed for merits and demerits when used as a bone additive that was intervened during the surgical phase of dental implant placement; and suitable drug carriers that could withstand the functional load and deliver BMP at its lowest concentration.

To identify the carriers and concentration of BMP acceptable during surgical phase of implant placement and evaluate its efficacy in bone gain and osseointegration.

The study design was systematic review. Literature search as per PICO format was carried out within a time range from 2000 to July 2021. The review followed PRISMA guidelines and registered with the PROSPERO (CRD42020171667). The focus question included the population with an intra-oral implant placed in both animal and human models that were intervened with BMP-2 as an external additive biomaterial during the surgical phase. 2631 articles selected from the initial search were systematically filtered and yielded 16 articles that were qualitatively analysed.

The inter-rater reliability and level of agreement were 93.71%, κ(Kappa)>0.81 respectively. Results revealed the collagen carrier was commonly used for BMP delivery but lacked the property to withstand functional load and sustained release. BMP concentration varied in the range of 0.215µg to 0.8mg and the study revealed significantly indifferent outcome with low dose compared to the highest dose. BMP supplement showed better osseointegration in comparison with non-supplemented sites during the early period (within 6 months).

BMP at lower concentrations and with appropriate carriers, collagen sponge, hydroxyapatite/tricalcium phosphate (HA/TCP) with a bio ceramic bulking agent, and poly (D, L-lactide-co-glycolic acid) (PLGA)  reinforced with gelatin/HA/TCP accelerated bone growth during the initial stages of healing. Further long-term clinical trials for dental implant, analysing the sustained release of BMP with biodegradable and load-bearing carriers should be considered.

Statement of the Problem: 

The administration of both platelet rich plasma (PRP) and silicon dioxide (SiO2) to the bone defects accelerates bone repair and regeneration. Application of both of them may show synergistic regenerative effects. 

Our objective was to evaluate the possible synergistic osteogenic effects of PRP and SiO2 by injecting them using an ad hoc device.

In this experimental study, PRP/SiO2 scaffolds were fabricated by in situ casting method with the help of CaCl2 as the gelation factor and alginate as the stroma; and then, the biodegradability and spatial arrangement were assessed. The injectable scaffold was introduced into the 40 rabbit mandibular defects by an ad hoc two-channel injecting device. Five defects received PRP/SiO2/alginate as the treatment; the other sets of defects were treated by PRP/alginate, SiO2/alginate, and the last five defects served as the control groups by getting only alginate injections. The osteogenicity of the scaffolds was evaluated by radiological and histological procedures; they were then compared with each other. Analysis of variance and least significant difference tests were used to analyze the data.

The SiO2-treated group showed a significant higher bone area compared to PRP/ SiO2-treated groups on day 40 (p= 0.013). The number of osteocytes was higher in SiO2-treated than the control groups on both 20 and 40 days (p= 0.032 and 0.022, respectively). The number of osteoclast was also higher in SiO2-treated than PRP-treated group (p= 0.028). In addition, the cells of this group had just started to create Haversian systems in newly formed bone tissues.

Silica demonstrated a superior osteogenic activity over PRP in both short and long term periods. Evidently, they showed no synergistic regenerative effects. Our ad hoc device was efficiently capable of inserting the scaffolds into the injured sites with no difficulties or complications.

Statement of the Problem: 

Oral lichen planus (OLP) is an important inflammatory disease concerning its tendency to malignancy. The etiopathogenesis of this disease is still unknown. Medical geography uses geographic techniques to study factors related to location that cause uneven distribution of disease.

This study was conducted to map OLP in patients referred to Shiraz Dental School with medical geography techniques and investigate any possible relationship between the number of dentists and health-centers in different regions of Fars province with the number of referrals.

In this cross-sectional study, we evaluated the records of OLP patients referred to Shiraz Dental School from 2007 to 2018. Age, sex, place of residence, occupation, level of education, location of involvement, duration, and cutaneous involvement were recorded. The number of dentists and healthcare centers was obtained from the statistical records of Fars province. A Geographic Information System was used for the assessment of the spatial distribution of OLP. Ordinary least squares (OLS) and geographically weighted regression (GWR) indices were used for evaluating the relationship between the number of dentists and health centers with the number of referrals.

From 1006 records, 457 were studied, from which 71% were female (age range of 41-60). The regression coefficient was 0.937 for the number of dentists in each county compared to OLP referrals indicating a strong relationship. The regression coefficient was 0.983 for the number of health-centers. According to GWR analyses in Shiraz neighboring counties like Marvdasht, Sepidan, and Sarvestan, there is a positive relationship between the number of dentists and OLP patients.

The results revealed that dentists and health care centers had a good cognition of referring patients with OLP (as a premalignant lesion) for definite diagnosis in Fars counties. But both groups need more education in this matter. Moreover, referrals from settlements near Shiraz were more common because of their easier access.

Statement of the Problem: 

Root dilaceration is a developmental anomaly, which was first described in the 19th century as an abrupt change in the axial inclination between the crown and root of a tooth. Such an anomaly would potentially alter the dental therapeutic procedures and often demands special care. Hence, it is of great importance to diagnose dilaceration before starting any treatment procedure on the tooth.

The aim of the current study was to evaluate the prevalence of dilaceration in the first and second maxillary and mandibular molar teeth in Shiraz, Iran, using cone-beam computed tomography (CBCT) radiography.

In this retrospective study, 472 teeth from 141 CBCT images were studied. Each tooth was assessed by CBCT to diagnose dilaceration, its severity, direction, and anomaly location.

In this study, among 472 studied teeth, 136 teeth (28.8%) were diagnosed with root dilaceration. The most frequently affected tooth was the maxillary second molar tooth (45%). The results showed a statistically significant relationship between the gender of the patients and the prevalence of dilaceration. Most dilacerations were observed in distal direction, with a mild intensity, and located in the apical third of the roots.

In this study, CBCT was presented as an advanced method for diagnosing dilaceration in maxillary second molar teeth and especially in the mesial root, which can be influenced by gender and it can play an important role in designing the treatment plans.

Statement of the Problem:

 Oral epithelial dysplasia (OED) is a common potentially malignant lesion of oral cavity that should be managed to prevent likely malignant transformation.

Here, we present a combination of binary grading system with complementary immunohistochemical (IHC) staining for Ki67 biomarker to provide a reproducible OED grading system.

In this cross-sectional study, seventy out of one hundred OED specimens, which were accompanied by IHC stained microscopic slides for Ki67 antigen were evaluated by four independent oral pathologists. Both three-tier and binary grading systems based on WHO microscopic criteria were employed , blindly in a four-step method with at least two-week interval between each observation. Intra- and inter-observational reliability was assessed using Kappa statistical analysis.

OED diagnosis based on binary system showed significant intra-observer reliability comparing to three-tier system without biomarker. Moreover, OED diagnosis based on binary system using Ki67 biomarker showed significant inter-observer reliability comparing to diagnosis in three tier system and based on binary system without Ki67 biomarker showed significant inter-observer reliability comparing to diagnosis based on three-tier system without Ki67.

Here, we found that application of IHC staining for Ki67 biomarker in binary system might provide a more reliable grading method for oral pathologist form different educational background.

Statement of the Problem:

 Marginal bone loss (MBL) is an important factor in dental implant failure. The number of implants may affect MBL.

The aim of this study was to compare MBL in patients who received two or three implants for replacement of three missing teeth in the posterior mandible.

This prospective cohort study evaluated patients who required replacement of three missing teeth in the posterior mandible with dental implants. The patients were assigned to two groups. In the group 1, the edentulous area was restored with two implants and a pontic while three implants were placed for this purpose in the group 2. The MBL was compared between the two groups at 12 and 24 months after loading.

Forty-two implants were studied in group 1 and 36 implants in the group 2. The mean MBL was 0.90±0.12mm in the group 1 and 0.89±0.12mm in the group 2 at 12 months after loading. The mean MBL was 1.00±0.10mm in the group 1 and 0.98±0.10mm in the group 2 at 24 months after implant loading. The mean of MBL was not statistically different between the two groups at 12 months and 24 months (p> 0.05).

It seems that the use of two or three implants for replacement of three missing teeth in the posterior mandible is not associated with an increase in MBL.

Statement of the Problem: 

Staphylococcus aureus (S.A) can colonize in the skin, nasal cavity, and oral cavity. In the oral cavity, it can cause dental caries and periodontal disease. Mouthwashes can be used as an adjunct to mechanical plaque control methods to decrease the load of oral microorganisms. Chlorhexidine (CHX) is a commonly used antimicrobial mouthwash with side effects such as changing the sense of taste, tooth discoloration, oral mucosal burning, allergy, and xerostomia. It also has adverse systemic effects, if swallowed.

This study aimed to assess the effect of photodynamic therapy (PDT) with curcumin and methylene blue (MB) photosensitizers and different laser parameters on S.A colony count.

In this in vitro experimental study, 99 samples of standard-strain S.A were subjected to PDT with curcumin and MB photosensitizers with/without irradiation of 660 and 445 nm laser with different exposure parameters, and CHX in 9 groups (n=11). The samples were cultured in microplates containing Mueller-Hinton agar, and the number of colony forming units (CFUs) was counted after 24 h of incubation at 37°C. Data were analyzed by the Kruskal-Wallis and Dunn tests.

The minimum colony count was noted in CHX group (CFUs=0) followed by MB and 660nm diode laser group irradiated for 100 s (CFUs=147.2727±169.35707). The difference in this respect was significant between MB+660nm diode laser for 100 s and other groups (p< 0.05) except for the MB + 660 nm diode laser for 60 s group.

CHX is superior to laser for elimination of S.A. However, PDT with 660 nm diode laser + MB has considerable antimicrobial efficacy against S.A; increasing the duration of laser irradiation enhances the antimicrobial effect.

Statement of the Problem:

 The dilemma of microleakage at the composite-tooth interface is still a major challenge in operative dental practice.

This study aimed to compare the microleakage of universal adhesive with self-etch and total-etch bonding strategies for restoration of class-II primary molar cavities.

This in vitro, experimental study was conducted on 75 extracted primary molars. Class-II cavities were prepared in mesial or distal surfaces. The teeth were randomly divided into five groups of Adper Single Bond 2 (3M ESPE; St Paul, MN, USA), Clearfil SE Bond (Kuraray Noritake, Osaka, Japan), G-Bond (GC Corp., Tokyo, Japan), G-Premio Bond (GC Corp., Tokyo, Japan) with total-etch mode and G-Premio Bond with self-etch mode. Cavities were also restored with Nano-hybrid resin composite (Grandio, VOCO, Cuxhaven, Germany) and incubated for 24 hours, followed by thermocycling at 1500× between 5-55°C within a dwell time of 20 seconds. Later, the cavities were placed in 1M silver nitrate solution and evaluated under a stereomicroscope. Finally, microleakage was assessed quantitatively and qualitatively. One tooth in each group was prepared and evaluated under a scanning electron microscope (SEM). Data were analyzed using One-way ANOVA, Tukey's post hoc test and Chi-square test (p< 0.05).

The microleakage values were significantly different in the study groups (p< 0.05). The highest level of microleakage was noted in G-Bond and the lowest in G-Premio Bond with total etching. There was a significant correlation between the qualitative and quantitative measurements of microleakage.

The G-Premio Bond yielded acceptable results in terms of microleakage in total-etch and self-etch modes. However, additional etching is recommended to improve the quality of bonding.

Statement of the Problem: 

Subepithelial connective tissue graft (SCTG) is the gold standard treatment for root coverage procedure; however, this technique has limitations such as the need for a donor site and the difficulty of the harvesting procedure.  The potential benefits of Mucoderm®, a collagen matrix derived from porcine dermis, as an alternative treatment for root coverage can be investigated.

This study aimed to evaluate the efficacy of Mucoderm® for root coverage and compare its results with SCTG.

This double-blind split-mouth randomized clinical trial was conducted on seven patients with 12 bilateral gingival recessions (24 recession sites). Coronally advanced flap + Mucoderm® was applied on one side and coronally advanced flap + connective tissue graft (CTG) was applied on the contralateral side. We measured the periodontal pocket depth (PPD), clinical attachment level (CAL), recession depth (RD), keratinized tissue width (KTW) and gingival thickness (GT) with a surgical stent at baseline (preoperatively) and at 1, 3 and 6 months postoperatively. The Wilcoxon and Friedman tests were used to analyse the data.

The mean percentage of root coverage was 26% in the Mucoderm® group and 60% in the SCTG group at 6 months, compared with baseline. The mean percentage of root coverage was significantly different between the two groups (p Value<0.05). The results indicated that Mucoderm® did not increase the KTW, while CTG significantly increased the KTW (p Value< 0.05 at 1, 3 and 6 months).

The results of this study showed that Mucoderm® might not be an appropriate alternative for the CTG in root coverage procedures.

Statement of the Problem: 

Severe early childhood caries (S-ECC) is common among infants and toddlers. It has many problems and challenges for families as well as dentists in fields of prevention and treatment.

The study aimed to investigate the relationship between occurrence of S-ECC and level of lactose in breast milk, in infants aged 12 to 24 months.

This cross-sectional descriptive-analytical study was carried out from April to July 2020 on 30 children aged 12 to 24 months with or without S-ECC, who were sol-ely breastfed; their mothers answered questions about their breastfeeding habits. After the child's dental visit, the mother was asked to express 10 to 20ml of her milk as a sample and give it to the researchers. The samples were immediately kept at -4°C and then they were tested for lactose measurement. Finally, the test results were analyzed by SPSS 21 software using independent t-test.

The average amount of lactose in the breast milk of cases with S-ECC infant was 5.74g/100 ml and the average amount of lactose in the breast milk of cases without S-ECC infant was 4.64g/100 ml. There was no significant difference in lactose concentration between the two groups (p Value=0.64). The average number of breastfeeding times in cases with S-ECC infants was 7.87 per day while in the healthy cases this was 7.33 per day. There was no significant difference between the numbers of breastfeeding times per day in two groups.

According to this study, the amount of lactose in breast milk of children with S-ECC was slightly higher than the amount of lactose in breast milk in children with healthy teeth.

Adenomatoid odontogenic tumor (AOT) is a benign slow-growing, asymptomatic epithelial odontogenic neoplasm. This lesion has been known for its varied clinical and histoarchitectural patterns. Most AOTs occur intra-osseously in the anterior maxilla associated with the unerupted tooth. Clinically, AOT is sometimes misdiagnosed as an odontogenic cyst. Although enucleation and curettage for AOT is the most common treatment modality, accurate histopathological diagnosis is essential to avoid unnecessary extensive surgery. Here, we present a rare challenging case of an extrafollicular cystic adenomatoid odontogenic tumor occurring in the body of the mandible in a 23-year-old female patient, which was diagnosed clinically and radiographically as glandular odontogenic cyst. The diagnosis of adenomatoid odontogenic tumor was confirmed through histopathological examination.

Odontogenic carcinosarcoma is an extremely rare malignant mixed odontogenic tumor, in which both epithelial and mesenchymal component showing malignant cytology features. Due to paucity of reported cases, clinical appearance is unclear. Present study reports a mandibular odontogenic carcinosarcoma in a 33 years-old male with a history of painless mass in the anterior of mandible. The histopathological examination demonstrated a biphasic malignant neoplasm with both epithelial and mesenchymal component malignant features. There were follicles and strands of odontogenic epithelium, which were lined peripherally by ameloblast-like cells. Mesenchyme of tumor was highly cellular resembling dental papilla. Partial mandibular resection, consisting wide surgical excision with immediate reconstruction was accomplished.